# List of airline codes

This is a list of all airline codes. The table lists the IATA airline designators, the ICAO airline designators and the airline call signs (telephony designator). Historical assignments are also included for completeness.

## Airline codes for airlines beginning with:

* All
* 0–9
* A
* B
* C
* D
* E
* F
* G
* H
* I
* J
* K
* L
* M
* N
* O
* P
* Q
* R
* S
* T
* U
* V
* W
* X
* Y
* Z

## Codes

Airline codes :
| IATA | ICAO | Airline | Call sign | Country/Region | Comments |
| PR | BOI | 2GO | ABAIR | Philippines | |
| | EVY | 34 Squadron, Royal Australian Air Force | Multiple | | |
| | GNL | 135 Airways | GENERAL | United States | |
| 1A | n/a | Amadeus IT Group S.A. | n/a | Global | GDS and airline hosting system (CRS/PSS) |
| 1B | n/a | Sabre travel network Asia-Pacific (ex-Abacus) | n/a | APAC | Regional distribution |
| 1E | n/a | Travelsky | n/a | China | Local distribution system and hosting system (CRS/PSS) |
| 1F | n/a | Infini travel information, Inc. | n/a | Japan | Local distribution system (CRS) |
| 1G | n/a | Travelport (Galileo core) | n/a | Global | GDS (CRS) |
| 1H | n/a | Sirena travel | n/a | Russia | Local distribution system (CRS) and PSS |
| 1J | n/a | Axess international network, Inc. | n/a | Japan | Local distribution system (CRS) |
| 1K | n/a | AIRKIOSK | n/a | Global | Local distribution system (CRS) and PSS |
| 1M | n/a | Sirin | n/a | Russia | Local distribution system (CRS) and PSS |
| 1P | n/a | Travelport (Worldspan core) | n/a | Global | GDS (CRS) |
| 1S | n/a | Sabre travel network | n/a | Global | GDS and airline hosting system (CRS/PSS) |
| 1T | n/a | Hitit Computer Services | n/a | Turkey | Computer reservation system |
| 1U | n/a | Google/ITA | n/a | United States | Airline IT provider |
| 2T | TBS | Timbis Air | TIMBIS | Kenya | |
| | WYT | 2 Sqn No 1 Elementary Flying Training School | WYTON | United Kingdom | Royal Air Force |
| | TFU | 213th Flight Unit | THJY | Russia | State Airline |
| | CHD | 223rd Flight Unit | CHKALOVSK-AVIA | Russia | State Airline |
| | TTF | 224th Flight Unit | CARGO UNIT | Russia | State Airline |
| | TWF | 247 Jet Ltd | CLOUD RUNNER | United Kingdom | |
| | SEC | 3D Aviation | SECUREX | United States | |
| Q5 | MLA | 40-Mile Air | MILE-AIR | United States | |
| | QRT | 4D Air | QUARTET | Thailand | Defunct |
| | PIU | 43 Air School | PRIMA | South Africa | |
| 4D | ASD | Air Sinai | AIR SINAI | Egypt | Defunct |
| 4R | SEK | Star East Airline [de; fa; it; pl] | EAST RIDER | Romania | |
| 4O | AIJ | Interjet | ABC AEROLINEAS | Mexico | Defunct |
| 5W | WAZ | Wizz Air Abu Dhabi | WIZZ SKY | United Arab Emirates | |
| 7B | UBE | Bees Airline | FLOWER BEE | Ukraine | Defunct, AOC revoked due to not having any aircraft. |
| AQ | JYH | 9 Air | TRANS JADE | China | |
| | BRO | 2Excel Aviation | BROADSWORD | United Kingdom | |
| | GBT | A-Jet Aviation Aircraft Management | GLOBETROTTER | Austria | |
| | AJR | A-Jet Aviation Company | JET MONGOLIA | Mongolia | |
| | SFM | A-Safar Air Services | AIR SAFAR | Nigeria | |
| | AJJ | A2 Jet Leasing | ATLANTIC JET | United States | |
| | XXV | AASANA | | Bolivia | |
| | BBE | Ababeel Aviation | BABEL AIR | Sudan | |
| 1B | | Abacus International | | Singapore | Computer reservation system |
| BJ | ABJ | Abaeté Linhas Aéreas | ABAETE | Brazil | defunct |
| | NKP | Abakan Air | ABAKAN AIR | Russia | 2014 |
| RL | ABG | Abakan-Avia | ROYAL FLIGHT | Russia | |
| | ABE | Aban Air | ABAN | Iran | Former IATA code: K5 |
| | MRP | Abas | ABAS | Czech Republic | |
| | AHU | ABC Air Hungary | ABC HUNGARY | Hungary | defunct |
| | FTY | ABC Bedarfsflug | FLY TYROL | Austria | |
| W9 | AAB | Abelag Aviation | ABG | Belgium | defunct |
| | BDV | Aberdair Aviation | ABERDAV | Kenya | |
| | ROH | Aberdair Aviation Ghana | | Ghana | |
| | ADJ | Abidjan Air Cargo | ABICAR | Côte d'Ivoire | defunct |
| | ABP | ABS Jets | BAIR | Czech Republic | Named changed from Aba Air |
| M3 | TUS | ABSA Cargo | Turismo | Brazil | |
| | TTN | Absolute Flight Services | TITANIUM | South Africa | |
| GB | ABX | ABX Air | ABEX | United States | August 15, 2003 Air operations of former Airborne Express |
| | IAE | AC Insat-Aero | | Russia | defunct |
| | NCL | ACA (Ancargo Air) | ANCARGO AIR | Angola | defunct |
| | ACD | Academy Airlines | ACADEMY | United States | |
| ZA | CYD | AccessAir | CYCLONE | United States | defunct |
| | | Ace Air | ACE TAXI | South Korea | defunct as of September 2015 |
| | CFM | ACEF | ACEF | Portugal | Transportes Aéreos e Cargas, code no longer allocated |
| | ARO | Acero Taxi | ACERO | Mexico | |
| VX | AES | ACES Colombia | ACES | Colombia | defunct |
| | BVR | ACM Air Charter | BAVARIAN | Germany | |
| | BJT | ACM Aviation | BAY JET | United States | |
| | CRV | Acropolis Aviation | ACROPOLIS | United Kingdom | |
| | ORS | Action Air | AVIATION SERVICE | Italy | ICAO Code no longer allocated, defunct |
| | AXQ | Action Airlines (Action Air Charter) | ACTION AIR | United States | |
| | AVR | Active Aero Charter, Inc. | ACTIVE AERO | United States | |
| | RRM | Acvila Air-Romanian Carrier | AIR ROMANIA | Romania | defunct |
| | ADC | AD Astra Executive Charter | AD ASTRA | Poland | |
| | VUE | AD Aviation | FLIGHTVUE | United Kingdom | |
| | ADE | Ada Air | ADA AIR | Albania | defunct, former IATA code: ZY |
| KI | DHI | Adam Air | ADAM SKY | Indonesia | defunct |
| Z7* | ADK | ADC Airlines | ADCO | Nigeria | defunct; former name: Aviation Development Company |
| | ADW | ADC Airways | | Lebanon | defunct |
| | DSC | Addis Air Cargo Services | ADDIS CARGO | Ethiopia | |
| | DDS | Addis Airlines | ADDIS LINE | Ethiopia | DEFUNCT |
| | ADF | Ade, Aviación Deportiva | ADE AVIACION | Spain | |
| | TEC | ADI Shuttle Group | TECHJET | United States | |
| | SWH | Adler Aviation | SHOCKWAVE | Canada | |
| JP | ADR | Adria Airways | ADRIA | Slovenia | defunct as of September 2019 |
| | DRO | Adro Servicios Aereos | ADRO SERVICIOS | Mexico | |
| | ADV | Advance Air Charters | ADVANCE | Canada | defunct |
| | AXX | Advance Air Luftfahrtgesellschaft | SKY SHUTTLE | Germany | |
| | AAX | Advance Aviation | ADVANCE AVIATION | Thailand | |
| | XTJ | Advance Aviation Services | | United States | |
| 4G* | | Advance Leasing Company | | United States | |
| AN | WSN | Advanced Air | WINGSPAN | United States | 2015 |
| | ADD | Advanced Air Co. | | Japan | ICAO Code no longer allocated |
| | ADV | Advanced Flight Training | ADVANCED | United Kingdom | |
| | RDD | Adygea Airlines | ADLINES | Russia | defunct |
| | DVN | Adventia | | Spain | |
| | EBS | AEG Aviation Services | | United States | |
| A3 | AEE | Aegean Airlines | AEGEAN | Greece | |
| | ALS | Aeralp | AERALP | France | |
| | AEF | Aerea | | Spain | |
| | DRD | Aereo Dorado | AEREO DORADO | Mexico | |
| | FUT | Aereo Futuro | AEREO FUTURO | Mexico | |
| | MMG | Aereo Ruta Maya | RUTA MAYA | Guatemala | |
| | AGI | Aereo Transportes Los Angeles de America | ANGELES AMERICA | Mexico | |
| | WWG | Aereo WWG | AERO-W | Mexico | |
| | AED | Aernord | Aernspa | Italy | defunct |
| | AKR | Aero Clinker | AERO CLINKER | Mexico | |
| | RRB | Aero Club de Castellon | | Spain | |
| 9D | CND | Aero Continente Dominicana | CONDOMINICANA | Dominican Republic | defunct |
| | ARP | Aero Corporate | IVORYCORP | Côte d'Ivoire | |
| ML | AEK | Aero Costa Rica | ACORISA | Costa Rica | defunct |
| | EPU | Aero Elite Acapulco | ELITACAPULCO | Mexico | |
| | XPN | Aero Express | | Niger | |
| | AJP | Aero Jets Corporativos | AEROJETS | Mexico | |
| VF | TKJ | AJet | ANATOLIAN | Turkey | formerly AnadoluJet |
| | OWN | Aero Owen | AERO OWEN | Mexico | 2014 |
| | GHM | Aero Service Bolivia | | Bolivia | |
| | GLM | Aero Services Mali | GLOBAL MALI | Mali | |
| | GUE | Aero Servicio Guerrero | AERO GUERRERO | Mexico | |
| | ASR | Aero Sotravia | SOTRAVIA | France | 2014 |
| | ABA | Aero-Beta | AEROBETA | Germany | |
| DW | UCR | Aero-Charter Ukraine | CHARTER UKRAINE | Ukraine | |
| | EAP | Aero-Pyrenees | AERO-PYRENEES | France | |
| | AJH | Aeroaljarafe | ALJARAFE | Spain | |
| | AOB | Aerocaribe Coro | CARIBE CORO | Venezuela | |
| | ACR | Aerocenter, Escuela de Formación de Pilotos Privados de Avión | AEROCENTER | Spain | |
| | ERC | Aerocharter | | Guatemala | defunct |
| | BSO | Aeroclub Barcelona-Sabadell | | Spain | |
| | NVA | Aeroclub de Albacete | | Spain | |
| | LUE | Aeroclub de Alicante | | Spain | |
| | MLL | Aeroclub de Mallorca | MALLORCA | Spain | |
| | AVX | Aeroclub de Vitoria | | Spain | |
| | CTD | Aerocorporativos | AEROCORPORATIVOS | Mexico | |
| | RRO | Aerocredo | | Russia | |
| | DVI | Aerodavinci | AERO DAVINCI | Mexico | |
| | FAQ | Aerofaq | | Ecuador | |
| SU | AFL | Aeroflot | AEROFLOT | Russia | |
| P3 | PLS | Aeroflot-Plus | AEROPLUS | Russia | |
| | AEG | Aerofumigaciones Sam | FUMIGACIONES SAM | Chile | defunct |
| | AGQ | Aerogala | GALASERVICE | Chile | defunct |
| | ARH | Aerohelicopteros | AEROHELCA | Venezuela | 2014 |
| | BJU | AeroJet | JET EXPRESS | Angola | |
| | ARJ | Aerojet de Costa Rica, S.A. | | Costa Rica | |
| | LFT | Aerolift Company | LIFTCO | Sierra Leone | defunct |
| | LIN | Aerolimousine | AEROLIMOUSINE | Russia | |
| | PCP | Aerolínea Principal Chile | PRINCIPAL | Chile | |
| | ALT | Aerolíneas Centrales | AERLINEAS CENTRALES | Mexico | |
| | AHL | Aerolíneas Hidalgo | HIDALGO | Mexico | |
| | APR | Aerolíneas Primordiales | AEROPERLAS | Mexico | |
| | LDL | Aerologic | | Russia | |
| | VSC | Aeronautic de Los Pirineos | | Spain | |
| | PSE | Aeroservicio Sipse | SIPSE | Mexico | |
| | PSL | Aeroservicios Corporativos De San Luis | CORSAN | Mexico | |
| | EAE | Aeroservicios Ecuatorianos | AECA | Ecuador | |
| | AES | Aerosur Paraguay | AEROPARAGUAY | Paraguay | |
| | BTS | Aerotaxis Albatros | AEROLINEAS ALBATROS | Mexico | |
| | PRI | Aerotransportes Privados | AEROPRIV | Mexico | ICAO code in use by another company, call sign no longer allocated |
| | PVA | Aerotransportes Privados | TRANSPRIVADO | Mexico | |
| | VMX | Aeroventas de Mexico | VENTA | Mexico | 2014 |
| | ABU | Aerovías Bueno | AEROBUENO | Colombia | defunct |
| | ACB | African Cargo Services | AFRICARGO | Kenya | |
| | AAP | Arabasco Air Services | ARABASCO | Saudi Arabia | |
| | AAR | Americ Air | PATRIOT | United States | defunct |
| | AAS | Airtransservice | Aviaservice | Russia | defunct |
| | AAS | Austrian Air Services | AIR SERVICES | Austria | defunct |
| OB | AAT | Austrian Airtransport | AUSTRIAN CHARTER | Austria | defunct; former IATA code: U8, OG; former ICAO code: AUC |
| | AAV | Aly Aviation | | United Kingdom | defunct; former ICAO code: AAY |
| | AAW | Austin Airways | AUSTIN | Canada | defunct |
| SM | AAW | Allied Airways | | United Kingdom | defunct, taken over by British European Airways which went on to form British Airways. |
| | AAW | Almeta Air | ALMETA AIR | Austria | defunct |
| KJ | AAZ | Asian Air | | Kyrgyzstan | |
| | ABT | Ambeo | AMBITION | United Kingdom | |
| | ABE | Arberia Airlines | ARBERIA AIRLINES | Albania | defunct |
| | ACE | Air Charter Express | | Ghana | |
| YE | ACQ | Aryan Cargo Express | | India | |
| | ACS | Aircraft Sales and Services | AIRCRAFT SALES | Pakistan | |
| | ABS | Air Central | AIR CENTRAL | United States | defunct |
| | ADT | Arrendaminetos y Transportes Turisticos | ARRENDA-TRANS | Mexico | |
| | ADZ | Avio Delta | | Bulgaria | |
| | AED | Aie Experience Flight | AIE EXPERIENCE | United Kingdom | defunct |
| VJ | AFF | Africa Airways | AFRIWAYS | Benin | defunct |
| | AFM | AEROSPEED FORMATION ET MAINTENANCE | EPIC AIR | France | |
| | LBR | Air Costa (Lepl Project Limited) | | India | defunct |
| QH | FLA | Air Florida | PALM | United States | relaunching |
| 3O | MAC | Air Arabia Maroc | ARABIA MAROC | Morocco | This ICAO designator was previously used by Malta Air Charter |
| | MRY | Air Marine | AIR MARINE | France | |
| | PNK | Air Pink | AIRPINK | Serbia | |
| | PXG | Aitheras Aviation Group | | United States | |
| | AFN | African International Airlines | SIMBA | Lesotho | |
| HD | ADO | AIRDO | AIR DO | Japan | |
| | ACC | Airspeed Charter | | Jamaica | 2014 |
| | PNX | AIS Airlines | SPINNER | Netherlands | |
| | AVD | Álamo Aviación, S.L. | ALAMO | Spain | |
| | FSY | Algonquin Airlink | FROSTY | Canada | 2014 |
| | TTX | Alliance Air Charters | TWISTER | United States | |
| UJ | LMU | AlMasria Universal Airlines | ALMASRIA | Egypt | |
| | ALN | Alpha Jet, S.R.O. | TOLEMAC | Slovakia | 2014 |
| | APN | Alpine Airlines | AIR ALPES | France | |
| | BAH | The Amiri Flight | BAHRAIN | Bahrain | |
| A2 | AWG | Animawings | ANIMA WINGS | Romania | |
| | TLB | Atlantique Air Assistance | TRIPLE-A | France | |
| | UJX | Atlas Ukraine Airlines | ATLAS UKRAINE | Ukraine | 2014 |
| | AGM | Aviation West Charters | ANGEL MED | United States | 2015 |
| X9 | NVD | Avion Express | NORDVIND | Lithuania | Name changed from Nordic Solutions Air |
| | AZB | Azamat | TUMARA | Kazakhstan | defunct |
| 3S* | AEN | Aeroland Airways | AEROLAND | Greece | defunct, ICAO code no longer allocated |
| | NGF | Air Charity Network | ANGEL FLIGHT | United States | Re-allocated in 2014 was used by Angel Flight America |
| | WFT | Aircharters Worldwide | WORLD FLIGHT | United States | Allocated 2014 |
| JU | ASL | Air Serbia | AIR SERBIA | Serbia | Name changed from Aeroput to JAT Yugoslav Airlines to Jat Airways to Air Serbia. Formerly used JAT as ICAO code. |
| QH | LYN | Air Kyrgyzstan | ALTYN AVIA | Kyrgyzstan | Name changed from Kyrgyzstan |
| XK | CCM | Air Corsica | CORSICA | France | |
| | AHS | AHS Air International | HIGH SKY | Pakistan | |
| | ROO | Aero Roa | AERO ROA | Mexico | |
| | AWF | Aeroforward | | United States | |
| | SUP | Aeronautical Charters | SUN SPEED | United States | |
| | PSO | Aerotaxis Pegaso | AEROPEGASO | Mexico | |
| EI | EIN | Aer Lingus | SHAMROCK | Ireland | |
| EG | EUK | Aer Lingus UK | GREEN FLIGHT | United Kingdom | |
| | VLB | Air Volta | VOLTA | Bulgaria | |
| | FCJ | AirSprint US | FRACJET | United States | Previously used code "HAB" |
| | TEW | Airteam Charter | TEAMWORK | South Africa | |
| | STT | Alpha Star Charter | STAR CHARTER | Saudi Arabia | |
| | LBZ | Angkasa Super Service | | Indonesia | |
| | HEZ | Arrow Aviation | ARROW | Israel | |
| | UAH | Air Experience Flight, Cranwell | | United Kingdom | Royal Air Force |
| | RVQ | Aero Jet International | REVA AIR | United States | |
| | ASK | Aerosky | MULTISKY | Spain | |
| | AEH | Aero4m | AEROCUTTER | Slovenia | |
| | ERO | Aeroecom | AEROECOM | Venezuela | |
| A8 | XAU | Aerolink Uganda | PEARL | Uganda | |
| | NKY | Aeromonkey | AEROMON | Mexico | |
| | AWP | Aeroworld Pakistan | | Pakistan | |
| | AGA | AG Air | GEOLINE | Georgia | |
| | ABZ | Air Ambulance Services | ISLAND LIFEFLIGHT | Bahamas | |
| RV | ROU | Air Canada Rouge | ROUGE | Canada | |
| | CNM | Air China Inner Mongolia | MENGYUAN | China | |
| | VRE | Air Côte d'Ivoire | COTE DIVORIE | Ivory Coast | |
| | AWL | Air Walser | | Malta | |
| | AXY | Air X Charter | LEGEND | Malta | |
| | OES | ART Aviation | ART AUSTRIA | Austria | |
| | ASF | Austrian Air Force | AUSTRIAN AIRFORCE | Austria | |
| | AVG | Aviation Legacy | AVILEF | Gambia | |
| 7A | AZY | Aztec Worldwide Airlines | AZTEC WORLD | United States | |
| 6U | ACX | Air Cargo Germany | LOADMASTER | Germany | defunct |
| | AAD | Aero Aviation Centre Ltd. | SUNRISE | Canada | Ceased operations 1995 |
| | SII | Aero Servicios Ejecutivos Internacionales | ASEISA | Mexico | |
| | BZS | Aero Biniza | BINIZA | Mexico | |
| | | Aero Comondu | AERO COMONDU | Mexico | |
| | AET | Aero-Palma | AERO PALMA | Spain | defunct |
| | ABM | Aero Albatros | ALBATROS ESPANA | Spain | |
| ZI | AAF | Aigle Azur | AIGLE AZUR | France | Former name: Lucas Aigle Azur; former IATA code: LK |
| | AAM | Aim Air | | Moldova | |
| | AAO | Atlantis Airlines (USA) | ATLANTIS AIR | United States | |
| | AAP | Aerovista Airlines | AEROVISTA GROUP | Kyrgyzstan | defunct |
| AE | AE | Air Ceylon | CEYLON | Sri Lanka | defunct |
| 4K* | AAS | Askari Aviation | AL-ASS | Pakistan | |
| | AAU | Australia Asia Airlines | AUSTASIA | Australia | Subsidiary merged into Qantas; former IATA code: IM |
| | AAV | Astro Air International | ASTRO-PHIL | United States | |
| 8U | AAW | Afriqiyah Airways | AFRIQIYAH | Libya | |
| Q9 | AFU | Afrinat International Airlines | AFRINAT | Gambia | defunct, ICAO code no longer allocated |
| | AAX | Afric'air Express | AFREX | Côte d'Ivoire | defunct |
| | BRL | Air Brasd'or | BRASD'OR | Canada | |
| | AFH | Air Fecteau | FECTO | Canada | defunct |
| | BRM | Air 500 | BOOMERANG | Canada | defunct |
| | AAG | Atlantic Flight Training | ATLANTIC | United Kingdom | Changed from Air Atlantique in 2014 |
| KI | AAG | Air Atlantique | ATLANTIC | United Kingdom | Former name: Atlantic Air Transport; former IATA codes: 7M, DG, transferred to Atlantic Flight Training in 2014. |
| QB | AAJ | Air Alma | AIR ALMA | Canada | Ceased operations 10/01/2002; former IATA code: 4L |
| | ACS | Air Cess | | Liberia | defunct |
| | ADT | Air Dorval | AIR DORVAL | Canada | defunct |
| | AHN | Air Hungaria | AIR HUNGARIA | Hungary | |
| | AHR | Air Adriatic | ADRIATIC | Croatia | defunct |
| LD | AHK | Air Hong Kong | AIR HONG KONG | Hong Kong | |
| | AHS | Air Viggi San Raffaele | AIRSAR | Italy | |
| | AAI | Air Aurora | BOREALIS | United States | Former IATA code: AX |
| | ACU | Air Cargo Transportation System | AFRISPIRIT | Kenya | |
| | ACV | Air Charter Service | | United Kingdom | ICAO code no longer allocated |
| | ADC | Air Atlantic Dominicana | ATLAN-DOMINICAN | Dominican Republic | defunct |
| 2Y | ADW | Air Andaman | AIR ANDAMAN | Thailand | defunct 2004 |
| UX | AEA | Air Europa | EUROPA | Spain | |
| | AEQ | Air Express | LUNA | Sweden | |
| IG | AEY | Air Italy | AIR ITALY | Italy | merged into Meridiana |
| | ASW | Air Southwest Ltd. | AIRSOUTHWEST | Canada | defunct |
| | ASX | Air Special | AIRSPEC | Czech Republic | |
| NX | AMU | Air Macau | AIR MACAO | Macao | |
| 6A | AMW | Armenia Airways | ARMENIA | Armenia | |
| HM | SEY | Air Seychelles | SEYCHELLES | Seychelles | |
| | SFB | Air Sofia | AIR SOFIA | Bulgaria | defunct |
| | BRF | Air Bravo | AIR BRAVO | Uganda | |
| AF | AFR | Air France | AIRFRANS | France | |
| | ACG | Air Partner | AIR PARTNER | United Kingdom | |
| SB | ACI | Air Caledonie International | AIRCALIN | France | |
| | VSG | AirClass Airways | VISIG | Spain | formerly Visig Operaciones Aéreas |
| EH | AKX | Air Nippon Network Co. Ltd. | ALFA WING | Japan | merged into ANA Wings |
| | ALM | Air ALM | ANTILLEAN | Netherlands Antilles | defunct |
| | ALN | Air Lincoln | CHICAGO LINCOLN | United States | |
| | ACM | Air Caledonia | WEST CAL | Canada | |
| ED | AXE | AirExplore | GALILEO | Slovakia | |
| | AGM | Air Guam | AIR GUAM | United States | |
| ZW | AWI | Air Wisconsin | WISCONSIN | United States | |
| | ALU | Air Luxor STP | LUXORJET | São Tomé and Príncipe | |
| YI | RSI | Air Sunshine | AIR SUNSHINE | United States | |
| GN | AGN | Air Gabon | GOLF NOVEMBER | Gabon | defunct |
| 9T | RUN | Air ACT | CARGO TURK | Turkey | |
| | AFV | Air Afrique Vacancies | AFRIQUE VACANCE | Côte d'Ivoire | |
| ZB | ABN | Air Albania | AIR ALBANIA | Albania | |
| 3J | AAQ | Air Alliance | LIAISON | Canada | defunct |
| WP | ATW | Air Antwerp | DEVIL | Belgium | defunct |
| BX | ABL | Air Busan | AIR BUSAN | South Korea | |
| | ACH | Air Cargo Plus | AIR PLUS | Liberia | |
| | AAT | Air Central Asia | | Kyrgyzstan | |
| LB | LEP | Air Costa | LECOSTA | India | |
| | AFS | Air Data | | United Kingdom | |
| GL | GRL | Air Greenland | GREENLAND | Greenland | |
| 3S | GUY | Air Guyane Express | GREEN BIRD | French Guiana | |
| | AHO | Air Hamburg | AIR HAMBURG | Germany | |
| NQ | AJX | Air Japan | AIR JAPAN | Japan | |
| IJ | LIB | Air Liberté | LIBERTE | France | defunct |
| TT | KLA | Air Lithuania | KAUNAS | Lithuania | defunct |
| QM | AIM | Air Malawi | MALAWI | Malawi | defunct |
| L6 | AMI | Air Maldives | AIR MALDIVES | Maldives | defunct |
| ML | BIE | Air Mediterranee | MEDITERRANEE | France | defunct |
| P8 | MKG | Air Mekong | MEKONG | Vietnam | defunct |
| | AMG | Air Minas Linhas Aéreas | AIR MINAS | Brazil | defunct |
| 4O | MNE | Air Montenegro | MOUNT EAGLE | Montenegro | |
| | TAH | Air Moorea | AIR MOOREA | France | defunct |
| | ANV | Air Nevada | AIR NEVADA | United States | |
| NZ | ANZ | Air New Zealand | NEW ZEALAND | New Zealand | "NZ" used by New Zealand National Airways Corporation until its merger with Air New Zealand in 1978 "TE" used by TEAL from 1940-1965, then Air New Zealand from 1965-1990 |
| 4N | ANT | Air North Charter - Canada | AIR NORTH | Canada | |
| | AOE | Air One Executive | | Italy | |
| | AEI | Air Poland | POLISH BIRD | Poland | defunct |
| YP | APZ | Air Premia | AIR PREMIA | South Korea | |
| | AVZ | Air Valencia | AIR VALENCIA | Spain | |
| | AMO | Air Montreal (Air Holdings Inc.) | AIR MONTREAL | Canada | |
| BM | | Air Sicilia | | Italy | defunct |
| | AMR | Air Specialties Corporation | AIR AM | United States | Air American, Total Air |
| | AMS | Air Muskoka | AIR MUSKOKA | Canada | |
| | AOJ | Avcon Jet | ASTERIX | Austria | |
| | AJU | Air Jetsul | AIRJETSUL | Portugal | |
| | AKA | Air Korea Co. Ltd. | | Republic of Korea | |
| | LIV | Air Livonia | LIVONIA | Estonia | defunct |
| ZX | ABL | Air BC | AIRCOACH | Canada | Merged into Air Canada Jazz |
| | ABN | Air Fret Senegal | | Senegal | |
| | LJA | Air Jamahiriya Company | AIR JAMAHIRIYA | Libya | ICAO code no longer allocated |
| G8 | AGB | Air Service Gabon | | Gabon | defunct |
| 7T | AGV | Air Glaciers | AIR GLACIERS | Switzerland | |
| | MVM | Air Cargo America | PEGASUS | United States | |
| | AMY | Air Ambar | AIR AMBAR | Dominican Republic | |
| 6V | VGA | Air Vegas | AIR VEGAS | United States | defunct |
| | AOU | Air Tractor | AIR TRACTOR | Croatia | |
| | APA | Air Park Aviation Ltd. | CAN-AM | Canada | |
| | APG | Air People International | AIR PEOPLE | Thailand | |
| NH | ANA | All Nippon Airways | ALL NIPPON | Japan | |
| | ANB | Air Navigation And Trading Co. Ltd. | AIR NAV | United Kingdom | Former ICAO code: AAT |
| | NGO | Air-Angol | AIR ANGOL | Angola | |
| TZ | TWG | air-taxi Europe | TWINGOOSE | Germany | |
| | NGP | Air Nigeria | REGAL EAGLE | Nigeria | defunct |
| 2Q | SNC | Air Cargo Carriers | NIGHT CARGO | United States | |
| | SND | Air Samarkand | ARSAM | Uzbekistan | |
| V7 | SNG | Air Senegal International | AIR SENEGAL | Senegal | defunct |
| | SNY | Air Sandy | AIR SANDY | Canada | |
| | AII | Air Integra | INTEGRA | Canada | |
| | BFF | Air Baffin | AIR BAFFIN | Canada | renamed to Air Nunavut |
| | BDM | Air Bandama | BANDAMA | Ivory Coast | |
| AB | BER | Air Berlin | AIR BERLIN | Germany | defunct |
| | ABT | Air Brousse | AIR BROUSSE | Canada | defunct |
| | APV | Air Plan International | AIR PLAN | Democratic Republic of the Congo | |
| | ARX | Air Xpress, Inc. | AIREX | United States | |
| | HTT | Air Tchad | HOTEL TANGO | Chad | |
| | ARZ | Air Resorts | AIR RESORTS | United States | |
| | ASB | Air-Spray 1967 Ltd. | AIR SPRAY | Canada | |
| | ASC | Air Star Corporation | AIR STAR | Canada | |
| 4D | ASD | Air Sinai | AIR SINAI | Egypt | |
| | AQN | Air Queensland | BUSHAIR | Australia | defunct |
| | ARC | Air Routing International Corp. | | United States | |
| QN | ARR | Air Armenia | AIR ARMENIA | Armenia | |
| | AIL | Air Illinois | AIR ILLINOIS | United States | defunct |
| AI | AIC | Air India Limited | AIRINDIA | India | |
| | AIG | Air Inter Gabon | | Gabon | |
| PJ | SPM | Air Saint Pierre | SAINT-PIERRE | France | |
| SZ | WOW | Air Southwest | SWALLOW | United Kingdom | defunct |
| | ATJ | Air Traffic GmbH | SNOOPY | Germany | |
| 8C | ATN | Air Transport International | AIR TRANSPORT | United States | |
| | ATQ | Air Transport Schiphol | MULTI | Netherlands | |
| | ATS | Air Transport Service | | Democratic Republic of the Congo | |
| | AVG | Air Falcon | DJIBOUTI FALCON | Djibouti | |
| | AUX | Air Uganda International Ltd. | | Uganda | |
| NF | AVN | Air Vanuatu | AIR VAN | Vanuatu | |
| ZB | BUB | Air Bourbon | BOURBON | Reunion | defunct |
| CC | ABD | Air Atlanta Icelandic | ATLANTA | Iceland | |
| | AIE | Air Inuit | AIR INUIT | Canada | |
| | AIS | Air Sureste | SURESTE | Spain | |
| RB | SBK | Air Srpska | Air Srpska | Bosnia and Herzegovina | defunct |
| TN | THT | Air Tahiti Nui | TAHITI AIRLINES | France | |
| SW | NMB | Air Namibia | NAMIBIA | Namibia | defunct |
| | NSK | Air Intersalonika | INTERSALONIKA | Greece | |
| | NTL | Air Anatolia | AIR ANATOLIA | Turkey | defunct |
| | SGA | Air Saigon | AIR SAIGON | Vietnam | |
| | AFW | Afrique Regional Airways | AFRAIR | Côte d'Ivoire | defunct |
| AW | AFW | Africa World Airlines | BLACKSTAR | Ghana | |
| | ACX | Air Charters | PARAIR | Canada | defunct |
| PE | AEL | Air Europe Italy | AIR EUROPE | Italy | defunct |
| JM | AJM | Air Jamaica | JAMAICA | Jamaica | merged into Caribbean Airlines; ICAO and IATA codes no longer used. |
| | AWN | Air Niamey | AIR NIAMEY | Niger | |
| | AWT | Air West | AIR WEST | Canada | |
| 6G | AWW | Air Wales | RED DRAGON | United Kingdom | defunct, ICAO code no longer allocated |
| TX | FWI | Air Caraïbes | FRENCH WEST | France | |
| IX | AXB | Air India Express | EXPRESS INDIA | India | |
| | AXD | Air Express | AIR SUDEX | Sudan | |
| | BSB | Air Wings | ARBAS | Moldova | |
| BT | BTI | Air Baltic | AIRBALTIC | Latvia | |
| | ANI | Air Atlantic (Nig) Limited | NIGALANTIC | Nigeria | |
| EL | ANK | Air Nippon | ANK AIR | Japan | merged into All Nippon Airways, ICAO code no longer allocated |
| YW | ANE | Air Nostrum | AIR NOSTRUM | Spain | |
| PX | ANG | Air Niugini | NIUGINI | Papua New Guinea | |
| G9 | ABY | Air Arabia | ARABIA | United Arab Emirates | |
| AC | ACA | Air Canada | AIR CANADA | Canada | |
| AP | LAV | AlbaStar | ALBASTAR | Spain | |
| E9 | MHS | Air Memphis | AIR MEMPHIS | Egypt | defunct |
| XT | AXL | Air Exel | EXEL COMMUTER | Netherlands | defunct |
| | AZF | Air Zermatt AG | AIR ZERMATT | Switzerland | |
| UM | AZW | Air Zimbabwe | AIR ZIMBABWE | Zimbabwe | |
| | MHU | Air Memphis | MEPHIS UGANDA | Uganda | |
| | MKH | Air Marrakech Service | AIR MARRAKECH | Morocco | |
| | AZX | Air Max Africa | AZIMA | Gabon | defunct |
| S2 | RSH | Air Sahara | SAHARA | India | renamed to Jetlite |
| | ATA | Air Transport Association | | United States | |
| TC | ATC | Air Tanzania | TANZANIA | Tanzania | |
| | XAC | Air Charter World | | United States | |
| 2J | VBW | Air Burkina | BURKINA | Burkina Faso | |
| | ATH | Air Travel Corp. | AIR TRAVEL | United States | |
| KM | AMC | Air Malta | AIR MALTA | Malta | |
| YT | TGA | Air Togo | AIR TOGO | Togo | defunct |
| | ASJ | Air Satellite | SATELLITE | Canada | defunct |
| | ASN | Air and Sea Transport | | Russia | |
| | ASS | Air Class, S.A. de C.V. | AIR CLASS | Mexico | |
| | NPL | Air Nepal International | AIR NEPAL | Nepal | defunct |
| | NPR | Air Napier | | New Zealand | defunct |
| | WAM | Air Taxi & Cargo | TAXI CARGO | Sudan | |
| | RSM | Air Somalia | AIR SOMALIA | Somali Republic | |
| | AWZ | AirWest | | Sudan | |
| G4 | AAY | Allegiant Air | ALLEGIANT | United States | |
| | AAZ | Angus Aviation | ANGUS | Canada | defunct |
| | ABA | Artem-Avia | ARTEM-AVIA | Ukraine | defunct |
| | ABB | African Business and Transportations | AFRICAN BUSINESS | Democratic Republic of the Congo | |
| | ABF | Aerial Oy | SKYWINGS | Finland | |
| | ABK | Alberta Citylink | ALBERTA CITYLINK | Canada | defunct, ICAO code no longer allocated |
| | ABO | APSA Colombia | AEROEXPRESO | Colombia | aka Aeroexpreso Bogota |
| O4 | ABV | Antrak Air | ANTRAK | Ghana | |
| GB | ABX | Airborne Express | ABEX | United States | August 14, 2003 merged into DHL |
| | ABZ | ATA Brasil | ATA-BRAZIL | Brazil | defunct |
| | ACC | Avcard Services | | United Kingdom | ICAO code no longer allocated |
| | ACY | Atlas Cargo Airlines | ATLAS CARGOLINES | Morocco | |
| | ADA | Airservices Australia | AUSCAL | Australia | Flight Inspection Unit |
| 8T | TID | Air Tindi | TINDI | Canada | |
| | ADB | Antonov Airlines | ANTONOV BUREAU | Ukraine | Antonov Design Bureau |
| | ADG | Aerea Flying Training Organization | AEREA TRAINING | Spain | |
| | ADI | Audeli Air | AUDELI | Spain | |
| | ADL | Aero Dynamics | COTSWOLD | United Kingdom | |
| | ADN | Aero-Dienst | AERODIENST | Germany | |
| | ADP | Aerodiplomatic | AERODIPLOMATIC | Mexico | |
| 3L | ADY | Air Arabia Abu Dhabi | Nawras | United Arab Emirates | |
| | ADQ | Avion Taxi | AIR DATA | Canada | 2695731 Canada Inc. |
| | ADS | Aviones de Sonora | SONORAV | Mexico | |
| | ADU | Airdeal Oy | AIRDEAL | Finland | |
| EM* | AEB | Aero Benin | AEROBEN | Benin | defunct |
| | AEC | Aerocésar | AEROCESAR | Colombia | defunct; aka Aerovías del César |
| | AED | Aerotrans Airlines | | Russia | defunct |
| | ADX | Anderson Aviation | ANDAX | United States | |
| | AEI | Aeroexpreso Interamericano | INTERAM | Colombia | defunct |
| | AEJ | Air Express | KHAKI EXPRESS | Tanzania | |
| | AEK | Aerocon | AEROCON | Bolivia | |
| | AEM | Aero Madrid | AEROMADRID | Spain | |
| KD | AEN | Air Enterprise | AIR ENTERPRISE | France | defunct |
| | AEO | Aeroservicios Ejecutivos Del Occidente | AERO OCCIDENTE | Mexico | |
| | AEP | Aerotec Escuela de Pilotos | AEROTEC | Spain | |
| AX | AAC | AmericanConnection | CONNECT AMERICA | United States | defunct |
| AN | AAA | Ansett Australia | ANSETT | Australia | defunct |
| | AAC | Army Air Corps | ARMYAIR | United Kingdom | |
| 5W | AEU | Astraeus | FLYSTAR | United Kingdom | defunct, ICAO code no longer allocated |
| | AEV | Aeroventas | AEROVENTAS | Mexico | |
| VV | AEW | Aerosvit Airlines | AEROSVIT | Ukraine | defunct |
| | AEX | Airway Express | AVCO | United States | ICAO code no longer allocated |
| | AEZ | Aerial Transit | AERIAL TRANZ | United States | |
| | AFA | Alfa Air | BLUE ALFA | Czech Republic | |
| WK | AFB | American Falcon | AMERICAN FALCON | Argentina | defunct |
| QQ | UTY | Alliance Airlines | UNITY | Australia | |
| | UVS | Air Universal | UNI-LEONE | Sierra Leone | defunct |
| | UVT | Auvia Air | AUVIA | Indonesia | |
| | AFC | African West Air | AFRICAN WEST | Senegal | |
| | AFE | Airfast Indonesia | AIRFAST | Indonesia | |
| FG | AFG | Ariana Afghan Airlines | ARIANA | Afghanistan | |
| RV* | AFI | Africaone | AFRICAWORLD | The Gambia | |
| Y2 | AFJ | Alliance Air | JAMBO | Uganda | Ceased operations 08/10/2000 |
| | AFK | Africa Air Links | AFRICA LINKS | Sierra Leone | |
| | AFO | Aero Empresa Mexicana | AERO EMPRESA | Mexico | |
| | AFQ | Alba Servizi Aerotrasporti | ALBA | Italy | |
| 5Z | AFX | Airfreight Express | | United Kingdom | Ceased operations 08/03/2002 |
| | AFY | Africa Chartered Services | AFRICA CHARTERED | Nigeria | |
| | AFZ | Africa Freight Services | AFREIGHT | Zambia | |
| | AGA | Aeronaves Del Centro | | Venezuela | |
| | AGC | Arab Agricultural Aviation Company | AGRICO | Egypt | |
| | AGF | Atlantic Gulf Airlines | ATLANTIC GULF | United States | defunct |
| 5D | SLI | Aeroméxico Connect | COSTERA | Mexico | |
| | AGG | Algoma Airways | ALGOMA | Canada | ICAO code no longer allocated |
| | AGH | Altagna | ALTAGNA | France | |
| | AGO | Angola Air Charter | ANGOLA CHARTER | Angola | |
| | AGP | AERFI Group | AIR TARA | Ireland | |
| 1A | AGT | Amadeus IT Group | AMADEUS | Spain | |
| | AGU | Angara Airlines | SARMA | Russia | |
| | AGW | Aero Gambia | AERO GAMBIA | Gambia | defunct, ICAO code no longer allocated |
| JJ | AGX | Aviogenex | GENEX | Serbia | defunct |
| | BLR | Atlantic Coast Airlines | BLUE RIDGE | United States | defunct |
| | BLZ | Aero Barloz | AEROLOZ | Mexico | |
| PL | PLI | Aeroperú | Aeroperu | Peru | defunct |
| 8A | BMM | Atlas Blue | ATLAS BLUE | Morocco | defunct |
| | BNB | Aero Banobras | AEROBANOBRAS | Mexico | |
| | AGY | Aero Flight Service | FLIGHT GROUP | United States | |
| | AGZ | Agrolet-Mci | AGROLET | Slovakia | |
| GD | AHA | Air Alpha Greenland | AIR ALPHA | Denmark | sold to Air Greenland |
| | AHC | Azal Avia Cargo | AZALAVIACARGO | Azerbaijan | Cargo Airline of the State Concern Azerbaijan Hava |
| | AHE | Airport Helicopter Basel, Muller & Co. | AIRPORT HELICOPTER | Switzerland | |
| | CJE | Aeroservices Corporate | BIRD JET | France | |
| | AHF | Aspen Helicopters | ASPEN | United States | |
| | AHG | Aerochago Airlines | AEROCHAGO | Dominican Republic | defunct |
| | AHH | Airplanes Holdings | AIRHOLD | Ireland | |
| | AHP | Aerochiapas | AEROCHIAPAS | Mexico | |
| HT | AHW | Aeromist-Kharkiv | AEROMIST | Ukraine | defunct |
| J2 | AHY | Azerbaijan Airlines | AZAL | Azerbaijan | |
| U3 | AIA | Avies | AVIES | Estonia | |
| 4Y | AIB | Airbus Industrie | AIRBUS INDUSTRIE | France | |
| KJ | AIH | Air Incheon | AIR INCHEON | South Korea | |
| RS | ASV | Air Seoul | AIR SEOUL | South Korea | |
| | AIK | African Airlines International Limited | AFRICAN AIRLINES | Kenya | |
| | AIN | African International Airways | FLY CARGO | Eswatini | |
| 5A | AIP | Alpine Air Express | ALPINE AIR | United States | |
| | AIU | Alicante Internacional Airlines | ALIA | Spain | |
| PA | ABQ | Airblue | AIRBLUE | Pakistan | |
| | THM | Airmark Aviation | THAI AIRMARK | Thailand | |
| | AIR | Airlift International | AIRLIFT | United States | defunct |
| | AIT | Airest | AIREST CARGO | Estonia | |
| | AIV | Airvias S/A Linhas Aéreas | AIRVIAS | Brazil | |
| W4 | BES | Aero Services Executive | BIRD EXPRESS | France | |
| | AIW | Atlantic Island Airways | TARTAN | Canada | |
| | AIX | Aircruising Australia | CRUISER | Australia | |
| | AIY | Aircrew Check and Training Australia | AIRCREW | Australia | |
| IZ | AIZ | Arkia Israel Airlines | ARKIA | Israel | |
| | AJA | Afghan Jet International Airlines | AFGHAN JET | Afghanistan | |
| | AJB | Aero JBR | AERO JBR | Mexico | |
| | AJE | Aero Jet Express | JET EXPRESS | Mexico | defunct |
| | AJI | Ameristar Jet Charter | AMERISTAR | United States | |
| | AJK | Allied Air | BAMBI | Nigeria | |
| | AJO | Aero Ejecutivo | AEROEXO | Mexico | defunct |
| | AJS | Aeroejecutivos Colombia | AEROEJECUTIVOS | Colombia | Aeroejecutivos Aeroservicios Ejecutivos |
| M6 | AJT | Amerijet International | AMERIJET | United States | |
| | AJV | ANA & JP Express | AYJAY CARGO | Japan | merged into Air Japan |
| | AJW | Alpha Jet International | ALPHAJET | United States | |
| | AJY | AJet | AYJET | Cyprus | defunct, ICAO code no longer allocated |
| | AKB | Aktjubavia | KARAB | Kazakhstan | |
| | AKC | Arca Aerovías Colombianas Ltda. | ARCA | Colombia | |
| | AKF | Anikay Air Company | ANIKAY | Kyrgyzstan | |
| | AKH | Akhal | AKHAL | Turkmenistan | |
| | MNI | Aeromilenio | AEROMIL | Mexico | |
| | AKK | Aklak Air | AKLAK | Canada | |
| 4A | AKL | Air Kiribati | KIRIBATI | Kiribati | |
| | AKN | Alkan Air | ALKAN AIR | Canada | |
| | AKW | Angkor Airways | ANGKORWAYS | Cambodia | defunct |
| | AKZ | AK Navigator LLC | ABSOLUTE | Kazakhstan | ICAO code no longer allocated |
| | ALB | Aero Albatros | ALBATROS | Mexico | |
| | ALD | Albion Aviation | ALBION | United Kingdom | |
| | ALE | Aeroalas Colombia | AEROALAS | Colombia | defunct |
| | ALF | Allied Command Europe (Mobile Force) | ACEFORCE | Belgium | |
| | FYS | American Flyers | AMERICAN FLYERS | United States | |
| | DFA | Aero Coach Aviation | AERO COACH | United States | |
| EV | ASQ | Atlantic Southeast Airlines | ACEY | United States | Merged into ExpressJet Airlines |
| | ALG | Air Logistics | AIRLOG | United States | |
| | ALL | Aerovallarta | VALLARTA | Mexico | |
| HP | AWE | America West Airlines | CACTUS | United States | Merged with US Airways |
| 6R | TNO | Aerotransporte de Carga Union | AEROUNION | Mexico | |
| | TND | Aero Taxis Cessna | TAXIS CESSNA | Mexico | |
| | TMP | Arizona Express Airlines | TEMPE | United States | |
| | ALO | Allegheny Commuter Airlines | ALLEGHENY | United States | US Airways Express |
| | ALP | Allpoints Jet | ALLPOINTS | China | |
| | ALP | Alpliner AG | ALPINER | Switzerland | Code now allocated to another user |
| | ALQ | Altair Aviation (1986) | ALTAIR | Canada | |
| VH | ALV | Aeropostal Alas de Venezuela | AEROPOSTAL | Venezuela | |
| | ALW | Alas Nacionales, S.A. | ALNACIONAL | Dominican Republic | |
| | ALY | Alyeska Air Service | ALYESKA | United States | |
| | ALZ | Alta Flights (Charters) Ltd. | | Canada | |
| | AMA | ATMA | ADIK | Kazakhstan | |
| | AMD | Aerolíneas Medellín | AEROLINEAS MEDELLIN | Colombia | defunct |
| | AMF | Ameriflight | AMFLIGHT | United States | |
| | AMH | Alan Mann Helicopters Ltd. | MANN | United Kingdom | ICAO code no longer allocated |
| | AMJ | Aviation Amos | AVIATION AMOS | Canada | |
| | AMK | Amerer Air | AMER AIR | Austria | |
| | AMM | Aeroputul International Marculesti | AEROM | Moldova | |
| DP | AMM | Air 2000 | JETSET | United Kingdom | defunct |
| | AMP | Aero Transporte S.A. (ATSA) | ATSA | Peru | |
| | AMQ | Aeromedicare Ltd. | LIFELINE | United Kingdom | No longer current |
| | AMQ | Aircraft Management and Consulting | AMEX | Poland | |
| TZ | AMT | ATA Airlines | AMTRAN | United States | defunct |
| YJ | AMV | AMC Airlines | AMC AIRLINES | Egypt | Aircraft Maintenance Company |
| AM | AMX | Aeroméxico | AEROMEXICO | Mexico | |
| | AMZ | Amiya Airline | AMIYA AIR | Nigeria | |
| | ANC | Anglo Cargo | ANGLO | United Kingdom | Defunct, ICAO code no longer allocated |
| | BRP | AeroBratsk | AEROBRA | Russia | |
| | ANH | Alajnihah for Air Transport | ALAJNIHAH | Libya | |
| | ANM | Aerotransportacion de Norteamerica | NORAM | Mexico | |
| | ANM | Antares Airtransport, Maintenance & Service GmbH | ANTARES | Germany | ICAO Code now allocated to another user |
| TL | ANO | Airnorth | TOPEND | Australia | |
| | ANQ | Aerolínea de Antioquia | ANTIOQUIA | Colombia | |
| OY | ANS | Andes Líneas Aéreas | AEROANDES | Argentina | |
| IW | AOM | AOM French Airlines | French Lines | France | defunct |
| | ANW | Aviación Del Noroeste, S.A. de C.V. | AVINOR | Mexico | defunct |
| | SAP | Avia Jaynar | TOBOL | Kazakhstan | |
| | EMS | Aero Servicios Empresariales | SERVIEMPRESARIAL | Mexico | |
| | AOA | Alcon Servicios Aéreos, S.A. de C.V. | ALCON | Mexico | |
| J6 | AOC | AVCOM | AERO AVCOM | Russia | |
| | AOD | Aero Vodochody | AERO CZECH | Czech Republic | |
| | AOF | Atair Pty Ltd. | ATAIR | South Africa | |
| 2D | AOG | Aero VIP | AVIP | Argentina | defunct |
| | MUN | Aeromundo Ejecutivo | AEROMUNDO | Mexico | |
| | MUR | Aerolínea Muri | MURI | Mexico | |
| | AOI | Astoria, Inc. | ASTORIA | Canada | defunct |
| | NRO | Aero Rent JSC | AEROMASTER | Russia | defunct |
| | NRP | Aeronord-Grup | AERONORD | Moldova | |
| | AOK | Aeroatlantico Colombia | | Colombia | defunct |
| | AOL | Angkor Airlines | ANGKOR AIR | Cambodia | defunct |
| | AON | Aero Entreprise | AERO ENTERPRISE | France | |
| | AOO | As, Opened Joint Stock Company | COMPANY AS | Ukraine | |
| | AOP | Aeropiloto | AEROPILOTO | Portugal | |
| VB | VIV | Aeroenlaces Nacionales | AEROENLACES | Mexico | Former ICAO code: AEN |
| | VIZ | Aerovis Airlines | AEROVIZ | Ukraine | |
| | VJE | AvJet Routing | | United Arab Emirates | |
| | VGF | Aerovista Gulf Express | VISTA GULF | United Arab Emirates | |
| | VER | Almaver | ALMAVER | Mexico | |
| | AOR | Afro International Ent. Limited | INTER-AFRO | Nigeria | |
| | SMX | Alitalia Express | ALIEXPRESS | Italy | |
| OE | AOT | Asia Overnight Express | ASIA OVERNIGHT | Philippines | |
| | AOV | Aero Vision | AEROVISION | France | |
| | AOX | Aerotaxi Del Valle | AEROVALLE | Colombia | |
| | APC | Airpac Airlines, Inc. | AIRPAC | United States | |
| | SVM | Aeroservicios Monterrey | SERVIMONTE | Mexico | |
| | APF | Amapola Flyg AB | AMAPOLA | Sweden | |
| | APH | Alpha Aviation, Inc. | AIRFLIGHT | United States | |
| | API | ASA Pesada, Lda. | ASA PESADA | Angola | |
| | APJ | Peach Aviation | AIR PEACH | Japan | |
| | PET | Aerotransporte Petrolero | AEROPETRO | Colombia | |
| GV | ARF | Aero Flight | Aero Fox | Germany | defunct |
| | BKL | Aircompany Barcol | BARCOL | Russia | |
| | BLA | All Charter Limited | ALL CHARTER | United Kingdom | ICAO code no longer allocated |
| | APL | Appalachian Flying Service, Inc. | APPALACHIAN | United States | |
| | APM | Airpac, Inc. | ALASKA PACIFIC | United States | |
| | APO | Aeropro | AEROPRO | Canada | defunct |
| | APP | AlpAvia d.o.o. | ALPAVIA | Slovenia | |
| | APQ | Aspen Aviation | ASPEN BASE | United States | |
| | APU | Aeropuma, S.A. | AEROPUMA | El Salvador | |
| JW | APW | Arrow Air | BIG A | United States | defunct |
| | APX | Apex Air Cargo | PARCEL EXPRESS | United States | |
| | APY | APA Internacional | APA INTERNACIONAL | Dominican Republic | |
| | AQA | Aeroatlas, S.A. | ATCO | Colombia | |
| | AQL | Aquila Air Ltd. | AQUILA | Canada | |
| | AQO | Aluminum Company Of America | ALCOA SHUTTLE | United States | Alcoa Aircraft Operations |
| | AQT | Avioquintana | AVIOQUINTANA | Mexico | |
| | AQU | AirQuarius Aviation | QUARIUS | South Africa | defunct |
| | AQZ | Aerodyne Charter Company | QUANZA | United States | |
| | ARA | Arik Air | ARIK AIR | Nigeria | |
| | ARB | Avia Air N.V. | AVIAIR | Aruba | |
| 2B | AWT | Albawings | ALBAWINGS | Albania | |
| 4C | ARE | Aires, Aerovías de Integración Regional, S.A. | AIRES | Colombia | renamed to LAN Colombia |
| AR | ARG | Aerolíneas Argentinas | ARGENTINA | Argentina | |
| | ARH | Arrowhead Airways | ARROWHEAD | United States | |
| | ARI | Aero Vics | AEROVICS | Mexico | |
| | SUN | Antillana De Navegación Aérea | | Dominican Republic | |
| | SUO | Aeroservicios De San Luis | SERVICIO SANLUIS | Mexico | |
| | SUP | Aerosuper | AEROSUPER | Mexico | |
| | ARK | Aero Link Air Services S.L. | LINK SERVICE | Spain | |
| | ARL | Airlec - Air Aquitaine Transport | AIRLEC | France | |
| | ARM | Aeromarket Express | AMEX | Spain | defunct |
| | ARO | Arrow Aviation Ltd. | ARROW | Canada | defunct |
| | KLD | Air Klaipėda | AIR KLAIPEDA | Lithuania | |
| | ARQ | Armstrong Air, Inc. | ARMSTRONG | Canada | |
| | ARS | Aeromet Servicios | METSERVICE | Chile | |
| | ART | Aerotal Aerolíneas Territoriales de Colombia Ltda. | AEROTAL | Colombia | defunct |
| | ARV | Aravco Ltd. | ARAVCO | United Kingdom | |
| | ARW | Aria | ARIABIRD | France | |
| | OST | Airline Alania | ALANIA | Russia | |
| | HUC | Aerolíneas de Techuacán | LINEAS TEHUACAN | Mexico | |
| | HUT | Aerotransportes Huitzilin | AEROHUITZILIN | Mexico | |
| | HUY | Aero Transportes Del Humaya | AERO HUMAYA | Mexico | |
| | ARY | Argosy Airways | GOSEY | United States | |
| AS | ASA | Alaska Airlines, Inc. | ALASKA | United States | |
| PL | ASE | Airstars | MOROZOV | Russia | defunct |
| | ASF | Air Schefferville, Inc. | SCHEFF | Canada | |
| | ASG | African Star Airways (PTY) Ltd. | AFRICAN STAR | South Africa | |
| | ASI | Aerosun International, Inc. | AEROSUN | United States | |
| | ASM | Awesome Flight Services (PTY) Ltd. | AWESOME | South Africa | |
| | ASO | Aero Slovakia | AERO NITRA | Slovakia | |
| | ASP | Airsprint | AIRSPRINT | Canada | |
| | ASR | All Star Airlines, Inc. | ALL STAR | United States | |
| | AST | Aerolíneas Del Oeste | AEROESTE | Mexico | |
| | WAP | Arrow Panama | ARROW PANAMA | Panama | |
| | ASV | Astravia-Bissau Air Transports Ltd. | ASTRAVIA | Guinea-Bissau | |
| OB | ASZ | Astrakhan Airlines | AIR ASTRAKHAN | Russia | defunct |
| | ATB | Atlantair Ltd. | STARLITE | Canada | |
| | ATD | Aerotours Dominicana | AEROTOURS | Dominican Republic | |
| | ATE | Atlantis Transportation Services, Ltd. | ATLANTIS CANADA | Canada | |
| | ATG | Aerotranscargo | MOLDCARGO | Moldova | |
| HC | ATI | Aero-Tropics Air Services | AEROTROPICS | Australia | defunct |
| | ATK | AeroTACA | AEROTACA | Colombia | defunct, Aerotaxi Casanare |
| | ATL | Atlas Air Service AG | AIR BREMEN | Germany | |
| FO | ATM | Airlines of Tasmania | AIRTAS | Australia | |
| | CPV | Air Corporate | AIRCORPORATE | Italy | |
| | ATP | ASTRAL Colombia - Aerotransportes Especiales Ltda. | ASTRAL | Colombia | |
| | FEO | Aeroferinco | FERINCO | Mexico | |
| | FES | Aero Taxis Y Servicios Alfe | AERO ALFE | Mexico | |
| | FFA | Avialesookhrana | AVIALESOOKHRANA | Russia | |
| | FFB | Africair Service | FOXTROT FOXTROT | Senegal | |
| | ATR | Atlas Airlines | ATLAS-AIR | United States | |
| | ATT | Aer Turas | AERTURAS | Ireland | defunct |
| | ATU | Atlant Aerobatics Ltd. | ATLANT HUNGARY | Hungary | |
| | ATV | Avanti Air | AVANTI AIR | Germany | |
| | ATW | Aero Trades (Western) Ltd. | AERO TRADES | Canada | defunct, ICAO code no longer allocated |
| OS | AUA | Austrian Airlines | AUSTRIAN | Austria | |
| IQ | AUB | Augsburg Airways | AUGSBURG-AIR | Germany | defunct |
| | TUP | Aviastar-Tu | TUPOLEVAIR | Russia | |
| RU | ABW | AirBridge Cargo | AIRBRIDGE CARGO | Russia | Former IATA: BO |
| | TUR | ATUR | | Ecuador | |
| | TXU | ATESA Aerotaxis Ecuatorianos | ATESA | Ecuador | |
| | TXX | Austin Express | COWBOY | United States | defunct |
| | AUD | Audi Air, Inc. | AUDI AIR | United States | |
| | AUF | Augusta Air Luftfahrtunternehmen | AUGUSTA | Germany | |
| | AUM | Air Atlantic Uruguay | ATLAMUR | Uruguay | |
| | AUN | Aviones Unidos | AVIONES UNIDOS | Mexico | |
| | AUP | Avia Business Group | | Russia | |
| | SVE | Aero Servicios Expecializados | AEROESPECIAL | Mexico | |
| GR | AUR | Aurigny Air Services | AYLINE | United Kingdom | |
| NO | AUS | Aus-Air | AUS-AIR | Australia | defunct |
| AU | AUT | Austral Líneas Aéreas | AUSTRAL | Argentina | |
| | AUU | Aurora Aviation, Inc. | AURORA AIR | United States | ICAO code no longer allocated |
| | AUY | Aerolíneas Uruguayas, S.A. | AUSA | Uruguay | |
| | AVF | Aviair Aviation Ltd. | CARIBOO | Canada | |
| | AVH | AV8 Helicopters | KENT HELI | United Kingdom | |
| | AVJ | Avia Traffic Company | ATOMIC | Kyrgyzstan | |
| | AVK | AV8 Helicopters | AVIATE-COPTER | South Africa | |
| | AVM | Aviación Ejecutiva Mexicana, S.A. | AVEMEX | Mexico | |
| | AVO | Aviation at Work | AVIATION WORK | South Africa | |
| | AVP | Avcorp Registrations | AVCORP | United Kingdom | No longer used |
| | AVP | Aviacion Corporativa de Peubla | AVIA PUEBLA | Mexico | |
| | LFP | Alfa Aerospace | ALFA-SPACE | Australia | |
| | LFR | Atlantic Airfreight Aviation | LANFREIGHT | São Tomé and Príncipe | |
| | AVS | Avialsa T-35 | AVIALSA | Spain | |
| | AVT | Asia Avia Airlines | ASIAVIA | Indonesia | defunct |
| | AVU | Avia Sud Aérotaxi | AVIASUD | France | |
| | AVV | Airvantage Incorporated | AIRVANTAGE | United States | |
| | AVW | Aviator Airways | AVIATOR | Greece | |
| | AVX | Aviapaslauga | PASLAUGA | Lithuania | defunct |
| | YRG | Air Yugoslavia | YUGAIR | Serbia | defunct; operations continue under Jat Airways |
| K8 | ZAK | Airlink Zambia | | Zambia | Zambia Skyways Limited |
| | ZZM | Agence Nationale des Aerodromes et de la Meteorologie (ANAM) | | Ivory Coast | |
| 4Y | BGA | Airbus Transport International | BELUGA | France | |
| B9 | BGD | Air Bangladesh | AIR BANGLA | Bangladesh | defunct |
| | BGF | Aviodetachment-28 | BULGARIAN | Bulgaria | |
| | BGG | Aero BG | AERO BG | Mexico | |
| | BHC | Aerotaxis De La Bahia | BAHIA | Mexico | |
| | BIV | Aviaservice | AVIASERVICE | Georgia | |
| | SZA | Aerolíneas de El Salvador | AESA | El Salvador | defunct |
| | AVY | Aerovaradero, S.A. | AEROVARADERO | Cuba | |
| | AWB | Airways International, Inc. | AIRNAT | United States | |
| | AWK | Airwork | AIRWORK | New Zealand | |
| | AWL | Australian Wetleasing | AUSSIEWORLD | Australia | |
| | AWO | Awood Air Ltd. | AWOOD AIR | Canada | |
| | AWR | Arctic Wings And Rotors Ltd. | ARCTIC WINGS | Canada | |
| | ISM | Auo Airclub AIST-M | STORK | Russia | |
| | AWS | Arab Wings | ARAB WINGS | Jordan | |
| | AWV | Airwave Transport, Inc. | AIRWAVE | Canada | |
| | AWY | Aeroway, S.L. | AEROWEE | Spain | |
| | AXH | Aeromexhaga | AEROMEXHAGA | Mexico | |
| | AXI | Aeron International Airlines, Inc. | AIR FREIGHTER | United States | |
| | AXK | African Express Airways | EXPRESS JET | Kenya | Former IATA code: QA; former ICAO code: AEK; former callsign: AFRICAN EXPRESS |
| AK | AXM | AirAsia | RED CAP | Malaysia | ICAO code no longer allocated |
| D7 | XAX | AirAsia X | XANADU | Malaysia | |
| DJ | WAJ | AirAsia Japan | WING ASIA | Japan | defunct |
| I5 | IAD | AirAsia India | ARIYA | India | Founded 28. Mar 2013 |
| | AXN | Alexandair | ALEXANDROS | Greece | defunct |
| | AXP | Aeromax | AEROMAX SPAIN | Spain | |
| | BNI | Alberni Airways | ALBERNI | Canada | |
| | BNZ | Aerolíneas Bonanza | AERO BONANZA | Mexico | |
| | BOC | Aerobona | AEROBONA | Mexico | |
| | AXR | Axel Rent, S.A. | RENTAXEL | Mexico | |
| | AXS | Altus Airlines | ALTUS | United States | |
| | AXV | AVA Airlines | AVA | Iran | |
| | AXX | Avioimpex A.D.p.o. | IMPEX | Macedonia | defunct |
| 6V | AXY | Axis Airways | AXIS | France | defunct |
| | AYD | Aladia Airlines | AIRLINES ALADIA | Mexico | defunct |
| | AYK | Aykavia Aircompany | | Armenia | ICAO code no longer allocated |
| | AYM | Airman, S.L. | AIRMAN | Spain | |
| | NPT | West Atlantic UK | NEPTUNE | United Kingdom | |
| | GBN | Atlantic Airlines | ATLANTIC GABON | Gabon | |
| EX | BJK | Atlantic Airlines | BLACKJACK | United States | |
| | HHA | Atlantic Airlines de Honduras | ATLANTIC HONDURAS | Honduras | defunct |
| | AYN | Atlantic Airlines, S.A. | ATLANTIC NICARAGUA | Nicaragua | |
| | AYS | Awsaj Aviation Services | | Libya | ICAO code no longer allocated |
| | AYT | Ayeet Aviation & Tourism | AYEET | Israel | |
| 3G | AYZ | Atlant-Soyuz Airlines | ATLANT-SOYUZ | Russia | defunct |
| AZ | AZA | Alitalia | ALITALIA | Italy | defunct |
| ZE | AZE | Arcus-Air Logistic | ARCUS AIR | Germany | |
| A2 | AZI | Astra Airlines | ASTRA | Greece | |
| | AZK | Azalhelikopter | AZALHELICOPTER | Azerbaijan | |
| | AZL | Africa One | SKY AFRICA | Zambia | defunct |
| | AZM | Aerocozumel | AEROCOZUMEL | Mexico | |
| | AZP | Arizona Pacific Airways | ARIZONA PACIFIC | United States | |
| | AZS | Aviacon Zitotrans Air Company | ZITOTRANS | Russia | |
| | AZT | Azimut, S.A. | AZIMUT | Spain | |
| | AZV | Azov Avia Airlines | AZOV AVIA | Ukraine | defunct, Asov-Avia, Aircompany |
| | MHC | Aero Jomacha | AERO JOMACHA | Mexico | |
| | AZY | Arizona Airways, Inc. | ARIZAIR | United States | |
| | AZZ | Azza Transport | AZZA TRANSPORT | Sudan | |
| | NAR | Air Continental Inc | NIGHT AIR | United States | |
| | NAU | Antanik-Air | ANTANIK | Ukraine | |
| | NER | Air Newark | NEWAIR | United States | |
| | NFF | Aircraft Support and Services | | Lebanon | ICAO code no longer allocated |
| | OBA | Aerobanana | AEROBANANA | Mexico | |
| | OBK | Amako Airlines | AMAKO AIR | Nigeria | |
| R7 | OCA | Aserca Airlines | AROSCA | Venezuela | |
| | NFS | Afrique Cargo Service Senegal | | Senegal | defunct |
| | NGC | Angoservice | ANGOSERVICE | Angola | |
| | NGE | Angel Airlines | ANGEL AIR | Thailand | defunct, ICAO code no longer allocated |
| | NGF | Angel Flight America | ANGEL FLIGHT | United States | Renamed Air Charity Network in 2014 |
| | OUL | Air Atonabee | CITY EXPRESS | Canada | defunct |
| | OVA | Aero Nova | AERONOVA | Spain | |
| | XPE | Amira Air | EXPERT | Austria | |
| | XSS | Aero Express Intercontinental | INTER EXPRESS | Mexico | |
| | TLR | Air Libya Tibesti | AIR LIBYA | Libya | |
| | OVC | Aerovic | | Ecuador | |
| | RVE | Airventure | AIRVENTURE | Belgium | |
| | RVI | Aero Servicios | AERO SERVICIOS | Mexico | |
| | RVL | Airvallee | AIR VALLEE | Italy | |
| | OVE | Aeromover | AEROMOVER | Mexico | |
| | OVI | Aerovías Ejecutivas | VIAS EJECUTIVAS | Mexico | |
| | PTD | Aero Servicio Pity | PITY | Mexico | |
| | PTE | Aero Copter | AERO-COP | Mexico | |
| | PLL | Air Pal | AIRPAL | Spain | Escuela De Pilots |
| | PLM | Air Pullmantur | PULLMANTUR | Spain | |
| RX | AEH | Aviaexpress | AVEX | Hungary | defunct |
| | PSG | Aviones Para Servirle | SERVIAVIONES | Mexico | |
| | SLU | Avio Sluzba | AVIO SLUZBA | Serbia | |
| | SCU | Air Scorpio | SCORPIO UNIVERS | Bulgaria | |
| | SIP | Air Spirit | AIR SPIRIT | United States | |
| | BMV | Alatau Airlines | OLIGA | Kazakhstan | |
| | GUG | Aviateca | AVIATECA | Guatemala | |
| | PXX | Aroostook Aviation | PINE STATE | United States | |
| | PYC | Aeropycsa | AEROPYCSA | Mexico | |
| | PVK | Association of Private Pilots of Kazakhstan | BORIS | Kazakhstan | ICAO code no longer allocated |
| | BAS | Aero Services | AEROSERV | Barbados | |
| | BBT | Air Bashkortostan | AGYDAL | Russia | defunct |
| | MCY | Ambulance Air Africa | MERCY | South Africa | |
| MQ | EGF | American Eagle Airlines | EAGLE FLIGHT | United States | Renamed Envoy Air, ICAO Code and Callsign withdrawn in 2014 |
| | PUE | Aeropuelche | PUELCHE | Chile | |
| | PUT | Aeroput | | Serbia | defunct |
| ZS | AZI | Azzurra Air | AZZURRA | Italy | defunct |
| FF | | Airshop | | Netherlands | |
| ML | ETC | African Transport Trading and Investment Company | TRANATTICO | Sudan | |
| | XCT | Aero Costa Taxi Aéreo | AEROCOSTAXI | Mexico | |
| | VRO | Aerovitro | AEROVITRO | Mexico | |
| | VRI | Aerotaxi Villa Rica | VILLARICA | Mexico | |
| | VEG | Aerovega | AEROVEGA | Mexico | |
| | VVG | Aerovilla | AEROVILLA | Colombia | |
| | VLR | Aerolíneas Villaverde | VILLAVERDE | Mexico | |
| WI | WIL | Aero Air | WILLIAMETTE | United States | |
| | VEJ | Aero Ejecutivos | VENEJECUTIV | Venezuela | |
| | WAB | Aero Industries Inc | WABASH | United States | |
| | VNG | Aero Servicios Vanguardia | VANGUARDIA | Mexico | |
| | VAD | Aero Taxi Los Valles | VALLES | Spain | |
| | VMR | Aero Vilamoura | AERO VILAMOURA | Portugal | ICAO code no longer allocated |
| | VLS | Aero Virel | VIREL | Mexico | |
| | XAA | Aeronautical Radio Inc | ROCKFISH|United States | |
| | VUO | Aerovuelox | AEROVUELOX | Mexico | |
| | VTM | Aeronaves TSM | AERONAVES TSM | Mexico | |
| VU | VUN | Air Ivoire | AIRIVOIRE | Ivory Coast | defunct |
| BP | BOT | Air Botswana | BOTSWANA | Botswana | |
| | XPR | Air-Rep | | United States | |
| | XLL | Air Excel | TINGA-TINGA | Tanzania | |
| | VAE | Air Evans | AIR-EVANS | Spain | Ecuela de Pilotos Privados |
| | WHY | Air Sorel | AIR SOREL | Canada | |
| | WDR | Air Net Private Charter | WIND RIDER | United States | |
| | XEC | Air Executive Charter | | Germany | |
| GS | UPA | Air Foyle | FOYLE | United Kingdom | defunct, ICAO code no longer allocated |
| | VTY | Air Midwest (Nigeria) | VICTORY | Nigeria | |
| VT | VTA | Air Tahiti | AIR TAHITI | French Polynesia | |
| 3N | URG | Air Urga | URGA | Ukraine | |
| | VDR | Air Vardar | VARDAR | Macedonia | ICAO code in use by another company, call sign no longer allocated |
| VL | VIM | Air VIA | CRYSTAL | Bulgaria | |
| | WLR | Air Walser | AIRWALSER | Italy | |
| | URA | Aircompany Rosavia | ROSAVIA | Ukraine | |
| | XLB | Aircraft Performance Group | | United States | |
| | WLA | Airwaves Airlink | AIRLIMITED | Zambia | |
| | XFX | Airways Corporation of New Zealand | AIRCORP | New Zealand | |
| | WAY | Airways | GARONNE | France | |
| | WGS | Airwings oy | AIRWINGS | Finland | |
| | XAK | Airkenya | SUNEXPRESS | Kenya | |
| | WPK | Air-Lift Associates | WOLFPACK | United States | |
| | VAB | Airtrans Ltd | | Russia | |
| | URP | ARP 410 Airlines | AIR-ARP | Ukraine | |
| | WPR | Auckland Regional Rescue Helicopter Trust | WESTPAC RESCUE | New Zealand | |
| | URR | Aurora Airlines | AIR AURORA | Slovenia | defunct, ICAO code no longer allocated |
| | UST | Austro Aéreo | AUSTRO AEREO | Ecuador | |
| | WLT | Aviation Partners | WINGLET | United States | |
| | VLV | Avialift Vladivostok | VLADLIFT | Russia | |
| | VME | Aviación Comercial de América | AVIAMERICA | Mexico | |
| | VVA | Aviast Air | IALSI | Russia | defunct |
| | WLV | Aviation North | WOLVERINE | United States | |
| FK | WTA | Africa West | WEST TOGO | Togo | |
| | VNT | Avient Air Zambia | AVIENT | Zambia | |
| | VZR | Aviazur | IAZUR | France | |
| | VID | Aviaprad | AVIAPRAD | Russia | defunct |
| G2 | VXG | Avirex | AVIREX-GABON | Gabon | |
| | VXX | Aviaexpress Aircompany | EXPRESSAVIA | Ukraine | |
| | XAM | AMR Services Corporation | ALLIANCE | United States | |
| | XAO | Airline Operations Services | | United States | |
| | VAZ | Airlines 400 | REMONT AIR | Russia | |
| V8 | VAS | ATRAN Cargo Airlines | ATRAN | Russian Federation | |
| | VAM | Ameravia | AMERAVIA | Uruguay | |
| K6 | KHV | Angkor Air | AIR ANGKOR | Cambodia | |
| | VBC | AVB-2004 Ltd | AIR VICTOR | Bulgaria | |
| | XKX | ASECNA | | France | |
| | XAT | AT and T Aviation Division | | United States | |
| | CAJ | Air Caraibes Atlantique | CAR LINE | France | |
| | CAO | Air China Cargo | AIRCHINA FREIGHT | China | |
| | CBE | Aerovías Caribe | AEROCARIBE | Mexico | |
| | CBO | Aerotaxi del Cabo | TAXI CABO | Mexico | |
| | CBS | Air Columbus | AIR COLUMBUS | Ukraine | |
| | CBV | Aereo Cabo | CABOAEREO | Mexico | |
| CA | CCA | Air China | AIR CHINA | China | |
| | CDA | Aerocardal | CARDAL | Chile | |
| Q6 | CDP | Aero Condor Peru | CONDOR-PERU | Peru | |
| | CDU | Aerotrans | | Russia | |
| | CDV | Airline Skol | SKOL | Russia | |
| | CFF | Aerofan | AEROFAN | Spain | |
| | CFR | Africa One | | Democratic Republic of the Congo | defunct |
| | CFV | Aero Calafia | CALAFIA | Mexico | |
| | CGB | Air Cargo Belize | CARGO BELIZE | Belize | |
| | CGV | Aero Clube Do Algarve | CLUBE ALGARVE | Portugal | |
| | CGW | Air Great Wall | CHANGCHENG | China | defunct |
| | CHJ | Aircompany Chaika | AIR CHAIKA | Ukraine | |
| | CHR | Air Charter Services | ZAIRE CHARTER | Democratic Republic of the Congo | |
| | CHV | Air Charter Professionals | CHARTAIR | United States | |
| | CID | Asia Continental Airlines | ACID | Kazakhstan | defunct, ICAO code no longer allocated |
| 5F | CIR | Arctic Circle Air Service | AIR ARCTIC | United States | defunct 2011 |
| | CKL | Aviation Charter Services | CIRCLE CITY | United States | |
| | CLL | Aerovías Castillo | AEROCASTILLO | Mexico | |
| | CLP | Aero Club De Portugal | CLUB PORTUGAL | Portugal | |
| | CMF | Air Care Alliance | COMPASSION | United States | |
| | CNE | Air Toronto | CONNECTOR | Canada | |
| | CNH | Aquila Air | CHENANGO | United States | |
| | CNU | Air Consul | AIR CONSUL | Spain | |
| | CNX | AllCanada Express | CANEX | Canada | defunct |
| | CPF | Airtechservice | TECHSERVICE | Ukraine | defunct |
| QC | CRD | Air Corridor | AIR CORRIDOR | Mozambique | defunct |
| NV | CRF | Air Central | AIR CENTRAL | Japan | Ceased operations 2010 |
| | CRJ | Air Cruzal | AIR CRUZAL | Angola | |
| | CRP | Aerotransportes Corporativos | AEROTRANSCORP | Mexico | |
| | CRQ | Air Creebec | CREE | Canada | |
| | CTA | Aero Charter and Transport | CHAR-TRAN | United States | |
| | CTE | Air Tenglong | TENGLONG | China | |
| | CTR | Aerolíneas Centauro | CENTAURO | Mexico | |
| | CUO | Aerocuahonte | CUAHONTE | Mexico | |
| CV | CVA | Air Chathams | CHATHAM | New Zealand | |
| CW | CWM | Air Marshall Islands | AIR MARSHALLS | Marshall Islands | |
| | CWP | Australian Customs Service | COASTWATCH | Australia | |
| | CYL | Air One Cityliner | CITYLINER | Italy | |
| | CYO | Air Transport | COYOTE | United States | |
| | CYE | Aerocheyenne | AEROCHEYENNE | Mexico | |
| AH | DAH | Air Algérie | AIR ALGERIE | Algeria | |
| | DAP | Aerovías DAP | DAP | Chile | |
| | DBA | Air Alpha | DOUBLE-A | United States | |
| | DBD | Air Niagara Express | AIR NIAGARA | Canada | |
| | DEF | Aviation Defense Service | TIRPA | France | |
| | DEG | Air Service Groningen | DEGGER | Netherlands | ICAO code and call sign no longer allocated |
| ER | DHL | Astar Air Cargo | D-H-L | United States | defunct, DHL |
| | DHM | Archer Aviation | ARCHER | United Kingdom | ICAO code no longer allocated |
| | DIC | Aeromedica | AEROMEDICA | Mexico | |
| | DIN | Aerodin | AERODIN | Mexico | |
| | DJU | Air Djibouti | AIR DJIB | Djibouti | defunct |
| EN | DLA | Air Dolomiti | DOLOMITI | Italy | |
| | DLS | Aero Modelo | AEROMODELO | Mexico | |
| | DLU | Aerolíneas del Sur | DEL SUR | Chile | defunct |
| | DMC | Aerodinamica de Monterrey | DINAMICAMONT | Mexico | |
| | DMI | Aeroservicios Dinamicos | AERODINAMICO | Mexico | |
| | DML | Aerotaxis Dosmil | | Mexico | |
| | DNA | Aerodespachos de El Salvador | AERODESPACHOS | El Salvador | |
| | DNC | Aerodynamics Málaga | FLYINGOLIVE | Spain | |
| | DNJ | Aerodynamics Incorporated | DYNAJET | United States | |
| NM | DRD | Air Madrid | ALADA AIR | Spain | defunct |
| | DRM | Airways Flight Training | DARTMOOR | United Kingdom | |
| | DRO | Aeronaves Del Noreste | AERONORESTE | Mexico | |
| 6R | DRU | Alrosa Air Company | MIRNY | Russia | |
| | DSK | Aero Algarve | SKYBANNER | Portugal | ICAO code no longer allocated |
| | DST | Aex Air | DESERT | United States | |
| | EAT | Air Transport | TRANS EUROPE | Slovakia | |
| EE | EAY | Aero Airlines | REVAL | Estonia | defunct |
| | EBC | Aero Ejecutivo De Baja California | CALIXJET | Mexico | |
| 4F | ECE | Air City | AIRCITY | Germany | |
| | ECG | Aero Ejecutivos RCG | EJECTUIVOS RCG | Mexico | |
| | ECL | Aeronáutica Castellana | AERO CASTELLANA | Spain | |
| | ECM | Aerolíneas Comerciales | AERO COMERCIALES | Mexico | |
| | EDA | Aerolineas Nacionales Del Ecuador | ANDES | Ecuador | defunct |
| | EET | Air Este | AESTE | Spain | |
| | EFC | Air Mana | FLIGHT TAXI | France | |
| | EJP | Aeroservicios Ejecutivos Corporativos | EJECCORPORATIVOS | Mexico | |
| E8 | ELG | Alpi Eagles | ALPI EAGLES | Italy | defunct, ICAO code no longer allocated |
| | ALX | ALPI Jets | ALPIJETS | Austria | |
| | END | Arrendadora y Transportadora Aérea | ARRENDADORA | Mexico | |
| | ENW | Aeronaves Del Noroeste | AERONOR | Spain | |
| | EOL | Airailes | EOLE | France | |
| RF | EOK | Aero K | AEROHANKUK | South Korea | established in May 2016; commenced operations on 15 April 2021 |
| | EOM | Aero Ermes | AERO ERMES | Mexico | |
| | EPL | Aero Transportes Empresariales | EMPRESARIALES | Mexico | |
| | EPE | Aero Empresarial | AEROEMPRESARIAL | Mexico | |
| KY | EQL | Air São Tomé and Príncipe | EQUATORIAL | São Tomé and Príncipe | defunct |
| | ERG | Avianergo | AVIANERGO | Russia | defunct |
| | ERI | Aero Servicios Regiomontanos | ASERGIO | Mexico | |
| | ERK | Aerosec | AEROSEC | Chile | |
| | ERM | Aeromaan | EOMAAN | Mexico | |
| | ESB | Aereosaba | AEREOSABA | Mexico | |
| | ESO | Avitat | | United Kingdom | |
| | ESU | Aerolíneas Ejecutivas Del Sureste | ALESUR | Mexico | |
| | ESZ | Aeronáutica La Esperanza | ESPERANZA | Mexico | |
| | ETE | Aero Siete | AEROSIETE | Mexico | |
| | EUK | Air Atlanta Europe | SNOWBIRD | United Kingdom | defunct |
| | EVE | Air Evex | SUNBEAM | Germany | |
| | EVR | Aeronautical Academy of Europe | DIANA | Portugal | |
| E2/E6 | EWE/EWL | Eurowings Europe | EUROPWINGS BLACK PEARL | Austria | |
| | EXG | Air Exchange | EXCHANGE | United States | |
| | FAC | Atlantic Helicopters | FAROECOPTER | Denmark | |
| | FAG | Argentine Air Force | FUAER | Argentina | |
| PC | FAJ | Air Fiji | FIJIAIR | Fiji | defunct |
| | FAN | AF-Air International | FANBIRD | Angola | |
| | FBW | Aviation Data Systems | | United States | |
| | FCI | Air Carriers | FAST CHECK | United States | |
| | FCO | Aerofrisco | AEROFRISCO | Mexico | |
| | FCU | Alfa 4 | | Mexico | |
| JH | FDA | Fuji Dream Airlines | FUJI DREAM | Japan | |
| | FDS | African Medical and Research Foundation | FLYDOC | Kenya | |
| | FGT | Aero Freight | FREIAERO | Mexico | |
| | FIC | Aerosafin | AEROSAFIN | Mexico | |
| OF | FIF | Air Finland | AIR FINLAND | Finland | |
| | FII | Aerodata Flight Inspection | FLIGHT CHECKER | Germany | ICAO code no longer allocated |
| | FIX | Airfix Aviation | AIRFIX | Finland | |
| FJ | FJI | Fiji Airways | PACIFIC | Fiji | |
| | FLD | Air Falcon | | Pakistan | |
| RC | FLI | Atlantic Airways | FAROELINE | Faroe Islands | |
| | FLP | Aeroclub Flaps | AEROCLUB FLAPS | Spain | defunct |
| QH | FLZ | Aero Leasing | AIR FLORIDA | United States | dba Air Florida |
| | FMT | Air Fret De Mauritanie | | Mauritania | |
| | FNM | Avio Nord | | Italy | |
| | FNO | Aeroflota Del Noroeste | RIAZOR | Spain | |
| | FNX | Aero Fenix | AERO FENIX | France | ICAO code no longer allocated |
| | FPY | African Company Airlines | AFRICOMPANY | Democratic Republic of the Congo | Defunct. ICAO code in use by another company. |
| | FRJ | Afrijet Airlines | AFRIJET | Nigeria | |
| | FRK | Afrika Aviation Handlers | AFRIFAST | Kenya | |
| | FRQ | Afrique Chart'air | CHARTER AFRIQUE | Cameroon | |
| | FRT | Aerofreight Airlines | | Russia | |
| | FST | Aeros Limited | FAST TRACK | United Kingdom | ICAO code no longer allocated |
| | FTC | Air Affaires Tchad | AFFAIRES TCHAD | Chad | |
| NY | FXI | Air Iceland | FAXI | Iceland | |
| 2P | GAP | Air Philippines | ORIENT PACIFIC | Philippines | |
| | GAU | Aerogaucho | AEROGAUCHO | Uruguay | |
| | GBJ | Aero Business Charter | GLOBAL JET | Germany | |
| | GCF | Aeronor | AEROCARTO | Spain | |
| | GCK | Aerogem Cargo | AEROGEM | Ghana | defunct |
| | GFO | Aerovías del Golfo | AEROVIAS GOLFO | Mexico | |
| | GGL | Aeronáutica | GIRA GLOBO | Angola | |
| ZX | GGN | Air Georgian | GEORGIAN | Canada | |
| | GHL | Aviance UK | HANDLING | United Kingdom | Gatwick Handling |
| | GHN | Air Ghana | AIR GHANA | Ghana | |
| | GIL | African International Transport | AFRICAN TRANSPORT | Guinea | |
| 2U | GIP | Air Guinee Express | FUTURE EXPRESS | Guinea | |
| | GIZ | Africa Airlines | AFRILENS | Guinea | |
| | GLL | Air Gemini | TWINS | Angola | |
| | GLT | Aero Charter | GASLIGHT | United States | |
| | GME | Aguilas Mayas Internacional | MAYAN EAGLES | Guatemala | |
| | GMM | Aerotaxis Guamuchil | AEROGUAMUCHIL | Mexico | |
| | GMS | Aeroservicios Gama | SERVICIOS GAMA | Mexico | |
| 0A | GNT | Amber Air | GINTA | Lithuania | |
| | GOA | Alberta Government | ALBERTA | Canada | |
| | GRE | Air Scotland | GREECE AIRWAYS | Greece | |
| DA | GRG | Air Georgia | AIR GEORGIA | Georgia | |
| | GRI | Air Cargo Center | | São Tomé and Príncipe | |
| LL | GRO | Allegro | ALLEGRO | Mexico | defunct (IATA code reallocated) |
| | GRR | Agroar - Trabalhos Aéreos | AGROAR | Portugal | |
| | GRX | Aircompany Grodno | GRODNO | Belarus | |
| | GSP | Airlift Alaska | GREEN SPEED | United States | |
| | GSV | Agrocentr-Avia | AGRAV | Kazakhstan | |
| | GTC | Altin Havayolu Tasimaciligi Turizm Ve Ticaret | GOLDEN WINGS | Turkey | |
| 5Y | GTI | Atlas Air | GIANT | United States | |
| | GTP | Aerotaxi Grupo Tampico | GRUPOTAMPICO | Mexico | |
| | GUA | Aerotaxis de Aguascalientes | AGUASCALIENTES | Mexico | |
| GG | GUY | Air Guyane | GREEN BIRD | French Guiana | |
| | GVI | Air Victoria Georgia | IRINA | Georgia | |
| H9 | HAD | Air d'Ayiti | HAITI AVIA | Haiti | |
| GG | HAH | Air Comores International | AIR COMORES | Comoros | |
| | HAT | Air Taxi | TAXI BIRD | France | |
| | HEI | Aerohein | AEROHEIN | Chile | |
| | HGH | Atlantic Air Lift | HIGHER | France | |
| | HID | Aviación Ejecutiva De Hildago | EJECUTIVA HIDALGO | Mexico | |
| | HJA | Air Haiti | AIRHAITI | Haiti | |
| HD | HLN | Air Holland | ORANGE | Netherlands | defunct |
| | HJT | Al Rais Cargo | AL-RAIS CARGO | United Arab Emirates | |
| | HKH | Air-Invest | HAWKHUNGARY | Hungary | |
| | HMA | Air Tahoma | TAHOMA | United States | ICAO code no longer allocated |
| | HMT | Air Nova | HAMILTON | United Kingdom | ICAO code no longer allocated |
| | HOM | Aero Homex | AERO HOMEX | Mexico | |
| | HPO | Almiron Aviation | ALMIRON | Uganda | |
| | HQO | Avinor | | Norway | |
| | HYR | Airlink Airways | HIGHFLYER | Ireland | |
| 8C | HZT | Air Horizon | HORIZON TOGO | Togo | |
| | ICM | Air Inter Cameroun | INTER-CAMEROUN | Cameroon | |
| | IFI | Air Lift | HELLAS LIFT | Greece | |
| | IKM | Aero Survey | EASY SHUTTLE | Ghana | Callsign changed from GHANA SURVEY |
| | ILK | Aero Airline | ILEK | Kazakhstan | |
| | IME | Airtime Charters | AIRTIME | United Kingdom | ICAO code no longer allocated |
| | IMN | Aerotaxis Cimarron | TAXI CIMARRON | Mexico | |
| | INA | Aero Internacional | AERO-NACIONAL | Mexico | |
| | ING | Aeroingenieria | AEROINGE | Chile | defunct |
| | INO | Aeroservicios Intergrados de Norte | INTENOR | Mexico | |
| | IPL | Airpull Aviation | IPULL | Spain | |
| | IRD | Arvand Airlines | ARVAND | Iran | |
| | IRH | Atlas Aviation Group | ATLAS AVIA | Iran | |
| | IRW | Aram Airline | ARAM | Iran | |
| | IRX | Aria Tour | ARIA | Iran | |
| | ITE | Aerotaxi S.R.O. | AEROTAXI | Czech Republic | |
| | ITF | Avita-Servicos Aéreos | AIR AVITA | Angola | |
| | ITI | AirSwift | AIRSWIFT | Philippines | |
| | ITO | Aero Citro | AERO CITRO | Mexico | |
| | IVE | Air Executive | COMPANY EXEC | Spain | |
| | IWS | Aviainvest | | Russia | |
| W9 | JAB | Air Bagan | AIR BAGAN | Myanmar | |
| | JAD | Aerojal | AEROJAL | Mexico | |
| | JAR | Airlink | AIRLINK | Austria | |
| | JEE | Ambjek Air Services | AMBJEK AIR | Nigeria | |
| | JKH | JETKONTOR AG | JETKONTOR | Germany | |
| | UTX | Avfinity | | United States | |
| | JMR | Alexandair | ALEXANDAIR | Canada | |
| | JMX | Air Jamaica Express | JAMAICA EXPRESS | Jamaica | |
| | JOA | Air Swift Aviation | | Australia | |
| | JOB | Aerojobeni | JOBENI | Mexico | |
| IP | JOL | Atyrau Air Ways | EDIL | Kazakhstan | |
| | JPR | Aerosmith Aviation | JASPER | United States | ICAO code no longer allocated |
| | JTS | Arrendamiento de Aviones Jets | AVIONESJETS | Mexico | |
| | JUA | Aero Juarez | JUAREZ | Mexico | |
| QK | JZA | Air Canada Jazz | JAZZ | Canada | |
| | KAA | Asia Aero Survey and Consulting Engineers | AASCO | Republic of Korea | ICAO code no longer allocated |
| | KAD | Air Kirovograd | AIR KIROVOGRAD | Ukraine | |
| | KAM | Air Mach | ICO-AIR | Italy | |
| | KAV | Air Kufra | AIRKUFRA | Libya | |
| | KEK | Arkhabay | ARKHABAY | Kazakhstan | ICAO code no longer allocated |
| | KFK | Aero Charter Krifka | KRIFKA AIR | Austria | |
| | KFT | Air Kraft Mir | AIR KRAFT MIR | Uzbekistan | |
| | KGD | Air Concorde | CONCORDE AIR | Bulgaria | |
| | KHH | Alexandria Airlines | | Egypt | |
| | KIE | Afit | TWEETY | Germany | |
| | KKB | Air South | KHAKI BLUE | United States | |
| KK | KKK | Atlasjet | ATLASJET | Turkey | |
| | KLB | Air Mali International | TRANS MALI | Mali | |
| | KLZ | Aerokaluz | AEROKALUZ | Mexico | |
| JS | KOR | Air Koryo | AIR KORYO | Democratic People's Republic of Korea | |
| | KOY | Araiavia | ALEKS | Kazakhstan | |
| | KRE | AeroSucre | AEROSUCRE | Colombia | |
| | KRT | Air Kokshetau | KOKTA | Kazakhstan | ICAO code no longer allocated |
| | KSI | Air Kissari | KISSARI | Angola | |
| | KTN | Aeronavigaciya | AERONAVIGACIYA | Ukraine | |
| | KVR | Alliance Avia | KAVAIR | Kazakhstan | |
| | KYC | Av Atlantic | DOLPHIN | United States | |
| KC | KZR | Air Astana | ASTANALINE | Kazakhstan | |
| | LAG | Aviation Legacy | AVILEG | Gambia | |
| | | Aerovías De Lagos | AEROLAGOS | Mexico | Was LAG |
| LV | LBC | Albanian Airlines | ALBANIAN | Albania | |
| | LBI | Albisa | ALBISA | Mexico | |
| | LBW | Albatros Airways | ALBANWAYS | Albania | |
| | LDG | Aerolíneas Aéreas Ejecutivas De Durango | DURANGO | Mexico | |
| 3S | BOX | Aerologic | GERMAN CARGO | Germany | |
| | LDN | Al-Donas Airlines | ALDONAS AIR | Nigeria | |
| QP | AKJ | Akasa Air | AKASA AIR | India |
| | LDR | Aero Lider | AEROLIDER | Mexico | |
| | LEM | Aleem | | Egypt | |
| | LET | Aerolíneas Ejecutivas | MEXEJECUTIV | Mexico | |
| H7 | LFA | Air Alfa | AIR ALFA | Turkey | |
| | LFC | Aero Control Air | LIFE FLIGHT CANADA | Canada | defunct |
| | LGN | Aerolaguna | AEROLAGUNA | Mexico | |
| | LHR | Al Ahram Aviation | AL AHRAM | Egypt | |
| D4 | LID | Alidaunia | ALIDA | Italy | |
| | LIE | Al-Dawood Air | AL-DAWOOD AIR | Nigeria | |
| | LKP | American Aviation | LAKE POWELL | United States | ICAO code no longer allocated |
| | LKS | Airlink Solutions | AIRLIN | Spain | |
| | LKY | Air Solutions | LUCKY | United States | |
| 9I | LLR | Air India Regional | ALLIED | India | |
| | LMA | Aerolima | AEROLIMA | Mexico | |
| | LML | Alamia Air | ALAMIA AIR | Libya | ICAO code no longer allocated |
| | LMP | Air Plus Argentina | AIR FLIGHT | Argentina | |
| | LMT | Almaty Aviation | ALMATY | Kazakhstan | |
| | LMX | Aerolíneas Mexicanas J S | LINEAS MEXICANAS | Mexico | |
| | LMY | Air Almaty | AGLEB | Kazakhstan | |
| | LMZ | Air Almaty ZK | ALUNK | Kazakhstan | |
| XL | LNE | Aerolane | AEROLANE | Ecuador | Líneas Aéreas Nacionales Del Ecuador |
| 4Z | LNK | Airlink | LINK | South Africa | |
| | LNT | Aerolíneas Internacionales | LINEAINT | Mexico | |
| | LOK | Alok Air | ALOK AIR | Sudan | |
| | LOU | Air Saint Louis | AIR SAINTLOUIS | Senegal | |
| FL | LPA | Air Leap | LEAP | Sweden | |
| | LPC | Alpine Aviation | NETSTAR | South Africa | |
| A6 | LPV | Air Alps Aviation | ALPAV | Austria | |
| | LRO | Alrosa-Avia | ALROSA | Russia | |
| | LRW | Al Rida Airways | AL RIDA | Mauritania | |
| | LSK | Aurela | AURELA | Lithuania | |
| | LSM | Aerobusinessservice | | Russia | defunct |
| | LSR | Alsair | ALSAIR | France | |
| | LTI | Aerotaxis Latinoamericanos | LATINO | Mexico | |
| | LUC | Albinati Aeronautics | ALBINATI | Switzerland | |
| TD | LUR | Atlantis European Airways | ATLANTIS | Armenia | defunct |
| | LVN | Aliven | ALIVEN | Italy | |
| | LVR | Aviavilsa | AVIAVILSA | Lithuania | |
| L8 | LXG | Air Luxor GB | LUXOR GOLF | Guinea-Bissau | |
| LK | LXR | Air Luxor | AIRLUXOR | Portugal | ICAO code no longer allocated |
| | LYT | Apatas Air | APATAS | Lithuania | |
| | LZP | Air Ban | DOC AIR | Bulgaria | |
| | LZR | Air Lazur | LAZUR BEE-GEE | Bulgaria | |
| | MAM | Aeródromo De La Mancha | AEROMAN | Spain | |
| MK | MAU | Air Mauritius | AIRMAURITIUS | Mauritius | |
| | MBA | Avag Air | AVAG AIR | Austria | |
| | MBB | Air Manas | AIR MANAS | Kyrgyzstan | |
| | MBC | Airjet Exploracao Aerea de Carga | MABECO | Angola | |
| | MBV | Aeriantur-M | AEREM | Moldova | defunct |
| | MCB | Air Mercia | WESTMID | United Kingdom | |
| | MCD | Air Medical | AIR MED | United Kingdom | |
| | MCO | Aerolíneas Marcos | MARCOS | Mexico | |
| | MDC | Atlantic Aero and Mid-Atlantic Freight | NIGHT SHIP | United States | |
| MD | MDG | Air Madagascar | AIR MADAGASCAR | Madagascar | |
| | MDX | Aerosud Charter | MEDAIR | South Africa | |
| | MEF | Air Meridan | EMPENNAGE | Nigeria | |
| | MFL | Aero McFly | MCFLY | Mexico | |
| | MGE | Asia Pacific Airlines | MAGELLAN | United States | |
| | MGS | Aeromagar | AEROMAGAR | Mexico | |
| | MIE | Aero Premier De Mexico | AEROPREMIER | Mexico | |
| 9U | MLD | Air Moldova | AIR MOLDOVA | Moldova | |
| | MLF | Amal Airlines | AMAL | Djibouti | |
| L9 | MLI | Air Mali | AIR MALI | Mali | defunct |
| | MLN | Air Madeleine | AIR MADELEINE | Canada | |
| | MMC | Aermarche | AERMARCHE | Italy | |
| | MMD | Air Alsie | MERMAID | Denmark | |
| | MMM | Aviation Company Meridian | AVIAMERIDIAN | Russia | |
| | MMP | AMP Incorporated | AMP-INC | United States | |
| | MMX | Airmax | PERUMAX | Peru | |
| | MNE | Aerolíneas Amanecer | AEROAMANECER | Mexico | |
| | MNG | Aero Mongolia | AERO MONGOLIA | Mongolia | |
| | MOC | Air Monarch Cargo | MONARCH CARGO | Mexico | |
| | MOP | Aeropublicitaria De Angola | PUBLICITARIA | Angola | |
| | MOR | Aerolíneas De Morelia | AEROMORELIA | Mexico | |
| A7 | MPD | Air Plus Comet | RED COMET | Spain | |
| QO | MPX | Aeromexpress | AEROMEXPRESS | Mexico | |
| | MQT | Air ITM | MUSKETEER | France | |
| | MRL | Aeromorelos | AEROMORELOS | Mexico | |
| | MRM | Aerocharter | MARITIME | Canada | |
| MR | MRT | Air Mauritanie | MIKE ROMEO | Mauritania | |
| SM | MSC | Air Cairo | AIR CAIRO | Egypt | |
| | MSK | Air Sport | AIR SPORT | Bulgaria | |
| | MSM | Aeromas | AEROMAS EXPRESS | Uruguay | |
| | MSO | Aerolíneas Mesoamericanas | MESO AMERICANAS | Mexico | |
| | MSV | Aero-Kamov | AERAFKAM | Russia | |
| | MTB | Aerotaxis Metropolitanos | AEROMETROPOLIS | Mexico | |
| | MTE | Aeromet Línea Aérea | AEROMET | Chile | defunct |
| | MTK | Air Metack | AIRMETACK | Angola | |
| | MTY | Air Montegomery | MONTY | United Kingdom | ICAO code no longer allocated |
| | MXO | Aerotaxi Mexicano | MAXAERO | Mexico | |
| | MYS | Aero Yaqui Mayo | AERO YAQUI | Mexico | |
| | MZK | AVC Airlines | | Japan | |
| | MZL | Aerovías Montes Azules | MONTES AZULES | Mexico | |
| 2V* | | Amtrak | | United States | Train services only |
| F4 | NBK | Albarka Air | AL-AIR | Nigeria | |
| | NEL | Aero Servicios de Nuevo Laredo | AEROLAREDO | Mexico | |
| | NGV | Angoavia | ANGOAVIA | Angola | |
| | NID | Aeroni | AERONI | Mexico | |
| | NIE | Aeroejecutiva Nieto | AERONIETO | Mexico | |
| AJ | NIG | Aero Contractors | AEROLINE | Nigeria | |
| | NKZ | Aerokuzbass | NOVOKUZNETSK | Russia | |
| | NRE | Aviones Are | AVIONES ARE | Mexico | |
| | NRS | Atlantic Richfield Company | NORTH SLOPE | United States | |
| | NSO | Aerolíneas Sosa | SOSA | Honduras | |
| | NTD | Aero Norte | | Mexico | |
| | NTV | Air Inter Ivoire | INTER-IVOIRE | Ivory Coast | |
| | NUL | Aeroservicios De Nuevo Leon | SERVICIOS NUEVOLEON | Mexico | |
| | NVI | Avial NV Aviation Company | NEW AVIAL | Russia | |
| | NWG | Airwing | NORWING | Norway | |
| | NXA | Air Next | BLUE-DOLPHIN | Japan | |
| | OAO | Arkhangelsk 2 Aviation Division | DVINA | Russia | |
| | OGI | Aerogisa | AEROGISA | Mexico | |
| | OLV | Aerolíneas Olve | OLVE | Mexico | |
| | OMG | Aeromega | OMEGA | United Kingdom | |
| | ONR | Air One Nine | EDER | Libya | ICAO code no longer allocated |
| | ONT | Air Ontario | ONTARIO | Canada | |
| | ORP | Aerocorp | CORPSA | Mexico | IATA changed to RCP; callsign changed to AEROCORPSA |
| | OSN | Aerosan | AEROSAN | Mexico | |
| | OSO | Aviapartner Limited Company | | Russia | |
| | PAJ | Aliparma | ALIPARMA | Italy | |
| | PBT | Air Parabet | PARABET | Bangladesh | |
| 8Y | PBU | Air Burundi | AIR-BURUNDI | Burundi | |
| | PCG | Aeropostal Cargo de Mexico | POSTAL CARGO | Mexico | |
| | PCK | Air Pack Express | AIRPACK EXPRESS | Spain | |
| | PCS | Air Palace | AIR PALACE | Mexico | |
| OT | PEL | Aeropelican Air Services | PELICAN | Australia | |
| | PEV | Peoples Vienna Line | PEOPLES | Austria | |
| | PFI | Aerolíneas Chihuahua | PACIFICO CHIHUAHUA | Mexico | |
| | PFT | Air Cargo Express International | PROFREIGHT | United States | |
| | PHR | Al Farana Airline | PHARAOH | Egypt | |
| | PHW | Ave.com | PHOENIX SHARJAH | United Arab Emirates | ICAO code no longer allocated |
| | PIE | Air South West | PIRATE | United Kingdom | |
| | PIF | Aeroservicios California Pacifico | AEROCALPA | Mexico | |
| | PKA | AST Pakistan Airways | PAKISTAN AIRWAY | Pakistan | |
| | PNL | Aero Personal | AEROPERSONAL | Mexico | |
| | PNU | Aero Servicios Platinum | AERO PLATINUM | Mexico | |
| | POY | Apoyo Aéreo | APOYO AEREO | Mexico | |
| | PRT | Atlantic Coast Jet | PATRIOT | United States | |
| AD | PRZ | Air Paradise International | RADISAIR | Indonesia | Defunct 2005 |
| | PZA | Aéreo Taxi Paraza | AEREO PARAZA | Mexico | |
| QD | QCL | Air Class Líneas Aéreas | ACLA | Uruguay | |
| | QEA | Aviation Consultancy Office | | Australia | |
| | QAT | Aero Taxi | AIR QUASAR | Canada | defunct |
| | QKC | Aero Taxi Aviation | QUAKER CITY | United States | |
| | QLA | Aviation Quebec Labrador | QUEBEC LABRADOR | Canada | |
| QS | QSC | African Safari Airways | ZEBRA | Kenya | |
| | QUI | Aero Quimmco | QUIMMCO | Mexico | |
| | RAD | Alada | AIR ALADA | Angola | |
| | RAI | Aerotur Air | DIASA | Kazakhstan | |
| | RAP | Air Center Helicopters | RAPTOR | United States | |
| | RBE | Aur Rum Benin | RUM BENIN | Benin | |
| | RBJ | Aeroserivios Del Bajio | AEROBAJIO | Mexico | |
| 4Y | RBU | Airbus France | AIRBUS FRANCE | France | |
| | RBV | Air Roberval | AIR ROBERVAL | Canada | |
| AG | ARU | Aruba Airlines | ARUBA | Aruba | |
| | RCC | Air Charters Eelde | RACER | Netherlands | ICAO code and call sign no longer allocated |
| | RCE | Aerocer | AEROCER | Mexico | |
| | RCF | Aeroflot-Cargo | AEROFLOT-CARGO | Russia | |
| MC | RCH | Air Mobility Command | REACH | United States | United States Air Force |
| | RCI | Air Cassai | AIR CASSAI | Angola | |
| | RCO | Aero Renta De Coahuila | AEROCOAHUILA | Mexico | |
| | RCP | Aerocorp | AEROCORPSA | Mexico | |
| | RCQ | Aerolíneas Regionales | REGIONAL CARGO | Mexico | |
| | RCU | Atlantic S.L. | AIR COURIER | Spain | |
| | RCX | Air Service Center | SERVICE CENTER | Italy | |
| | RDM | Air Ada | AIR ADA | Mauritania | |
| RE | REA | Aer Arann | AER ARANN | Ireland | |
| | REN | Aero-Rent | AERORENT | Mexico | |
| | RES | Australian Maritime Safety Authority | RESCUE | Australia | |
| UU | REU | Air Austral | REUNION | France | |
| | REY | Aero-Rey | AEROREY | Mexico | |
| | RFC | Aero Africa | AERO AFRICA | Eswatini | |
| ZP | AZP | Amaszonas Paraguay | GUARANI | Paraguay | |
| | RFD | Aerotransportes Rafilher | RAFHILER | Mexico | |
| | RGO | Argo | ARGOS | Dominican Republic | |
| | RGR | Avior Regional | AVIOR REGIONAL | Venezuela | 2014 |
| | RGT | Airbourne School of Flying | AIRGOAT | United Kingdom | ICAO code no longer allocated |
| | RHL | Air Archipels | ARCHIPELS | France | |
| | RIF | Aviation Ministry of the Interior of the Russian Federation | INTERMIN AVIA | Russian Federation | |
| | RIS | Aeris Gestión | AERIS | Spain | |
| 6K | RIT | Asian Spirit | ASIAN SPIRIT | Philippines | |
| | RJS | Aeroservicios Jet | ASERJET | Mexico | |
| | RKA | Air Afrique | AIRAFRIC | Ivory Coast | |
| A5 | RLA | Airlinair | AIRLINAIR | France | |
| NZ | RLK | Air Nelson | NELSON | New Zealand | defunct |
| | RLL | Air Leone | AEROLEONE | Sierra Leone | |
| QL | RLN | Aero Lanka | AERO LANKA | Sri Lanka | |
| | RLZ | Air Alize | ALIZE | France | |
| | RMD | Air Amder | AIR AMDER | Mauritania | |
| R3 | RME | Armenian Airlines | ARMENIAN | Armenia | defunct |
| MV | RML | Air Mediterranean | HELLASMED | Greece | |
| | RMO | Arm-Aero | ARM-AERO | Armenia | |
| | RMX | Air Max | AEROMAX | Bulgaria | |
| 2O | RNE | Air Salone | AIR SALONE | Sierra Leone | |
| | RNM | Aeronem Air Cargo | AEROMNEM | Ecuador | |
| | RNR | Air Cargo Masters | RUNNER | United States | |
| U8 | RNV | Armavia | ARMAVIA | Armenia | defunct, ICAO code no longer allocated |
| | ROE | Aeroeste | ESTE-BOLIVIA | Bolivia | |
| | ROH | Aero Gen | AEROGEN | Mexico | |
| | ROI | Avior Airlines | AVIOR | Venezuela | |
| | ROL | Aeroel Airways | AEROEL | Israel | ICAO code no longer allocated |
| BQ | ROM | Aeromar Lineas Aereas Dominicanas | BRAVO QUEBEC | Dominican Republic | defunct |
| | ROO | Aeroitalia | AEROITALIA | Italy | defunct |
| | ROD | Aerodan | AERODAN | Mexico | |
| P5 | RPB | AeroRepública | AEROREPUBLICA | Colombia | |
| | RPC | Aerolíneas Del Pacífico | AEROPACSA | Ecuador | |
| | RRC | Aero Roca | AEROROCA | Mexico | |
| | RRE | Aerotransportes Internacionales De Torreon | AERO TORREON | Mexico | |
| | RSC | Aerolíneas Ejecutivas Tarascas | TARASCAS | Mexico | |
| E4 | RSO | Aero Asia International | AERO ASIA | Pakistan | defunct |
| BF | RSR | Aero-Service | CONGOSERV | Republic of the Congo | |
| 5L | RSU | AeroSur | AEROSUR | Bolivia | |
| | RTE | Aeronorte | LUZAVIA | Portugal | ICAO code no longer allocated |
| | RTH | Artis | ARTHELICO | France | |
| | RTO | Arhabaev Tourism Airlines | ARTOAIR | Kazakhstan | |
| | RTQ | Air Turquoise | TURQUOISE | France | |
| | RTU | Aerotucan | AEROTUCAN | Mexico | |
| | RUD | Air Anastasia | ANASTASIA | Ukraine | |
| | RUM | Air Rum | AIR RUM | Sierra Leone | |
| | RVP | Air VIP | AEROVIP | Portugal | |
| | RVT | Aircompany Veteran | AIR-VET | Armenia | |
| | RWB | Alliance Express Rwanda | | Rwanda | Formerly Air Rwanda, revived as RwandAir after the Rwandan Genocide |
| | RWC | Arrow Ecuador Arrowec | ARROWEC | Ecuador | |
| | RWY | Aerogroup 98 Limited | TYNWALD | United Kingdom | ICAO code no longer allocated |
| | RXT | Aeroxtra | AERO-EXTRA | Mexico | |
| | RWS | Air Whitsunday | | Australia | |
| | RZL | Aero Zambia | AERO ZAMBIA | Zambia | |
| | RZN | Aero Zano | ZANO | Mexico | |
| | RZZ | Anoka Air Charter | RED ZONE | United States | |
| | SBH | Aerosaab | AEROSAAB | Mexico | |
| | SCD | Associated Aviation | ASSOCIATED | Nigeria | |
| | SCM | American Jet International | SCREAMER | United States | |
| EX | SDO | Air Santo Domingo | AERO DOMINGO | Dominican Republic | |
| | SDP | Aero Sudpacifico | SUDPACIFICO | Mexico | |
| | SEF | Aero Servicios Ejecutivas Del Pacifico | SERVIPACIFICO | Mexico | |
| JR | SER | Aero California | AEROCALIFORNIA | Mexico | |
| | SGV | Aerosegovia | SEGOVIA | Nicaragua | |
| | SHH | Airshare Holdings | AIRSHARE | United Kingdom | ICAO code no longer allocated |
| | SIY | Aerosiyusa | SIYUSA | Mexico | |
| | SIZ | Aero Silza | AEROSILZA | Mexico | |
| | SJN | Air San Juan | SAN JUAN | United States | |
| | SKP | Aero-North Aviation Services | SKIPPER | Canada | defunct |
| | SMI | Aero Sami | SAMI | Mexico | |
| Z3 | SMJ | Avient Aviation | AVAVIA | Zimbabwe | |
| | SOD | Aerolíneas Sol | ALSOL | Mexico | |
| | SOE | Air Soleil | AIR SOLEIL | Mauritania | |
| | SOG | Aero Soga | AEROSOGA | Guinea-Bissau | defunct |
| | SPD | Airspeed Aviation | SPEEDLINE | Canada | ICAO code no longer allocated |
| M3 | SPJ | Air Service | AIR SKOPJE | Macedonia | |
| | SPO | Aeroservicios Ejecutivos Del Pacifico | EJECTUIV PACIFICO | Mexico | |
| | SPY | Asian Aerospace Service | THAI SPACE | Thailand | |
| | SPZ | Airworld | SPEED SERVICE | South Africa | |
| | SQR | Alsaqer Aviation | ALSAQER AVIATION | Libya | ICAO code no longer allocated |
| | SRI | Air Safaris and Services | AIRSAFARI | New Zealand | |
| | SRV | Aero Servicio Corporativo | SERVICORP | Mexico | |
| | SSL | Air Sultan | SIERRA SULTAN | Sierra Leone | |
| | SSM | Aero 1 Pro-Jet | RAPID | Canada | defunct |
| | SSN | Airquarius Air Charter | SUNSTREAM | South Africa | ICAO code no longer allocated |
| | STK | Aeropac | SAT PAK | United States | |
| | STT | Air St. Thomas | PARADISE | United States | |
| | SUE | Aerolíneas Del Sureste | AEROSURESTE | Mexico | |
| 8D* | SUW | Astair | | Russian Federation | Name changed to Interavia Airlines |
| | SUY | Aerial Surveys (1980) Limited | SURVEY | New Zealand | |
| GM | SVK | Air Slovakia | SLOVAKIA | Slovakia | ICAO code no longer allocated |
| R3 | SYL | Aircompany Yakutia | AIR YAKUTIA | Russia | |
| | SYT | Aerosud Aviation | SKYTRACK | South Africa | |
| HC | SZN | Air Senegal | AIR SENEGAL | Senegal | |
| | TAA | Aeroservicios de La Costa | AERO COSTA | Mexico | |
| VW | TAO | Aeromar | TRANS-AEROMAR | Mexico | |
| | TBL | Aerotrebol | AEROTREBOL | Mexico | |
| | TBO | Aero Taxi de Los Cabos | AERO CABOS | Mexico | |
| JY | TCI | Air Turks and Caicos | KERRMONT | Turks and Caicos Islands | ICAO code no longer allocated |
| | TCO | Aerotranscolombina de Carga | TRANSCOLOMBIA | Colombia | |
| | TDG | Air Cargo Express | TURBO DOG | United States | |
| | TDT | Atlas Helicopters | TRIDENT | United Kingdom | |
| | TDY | Air Today | AIR TODAY | United States | |
| | TED | Aero Servicios Azteca | AEROAZTECA | Mexico | |
| | TIR | Antair | ANTAIR | Mexico | |
| | TLD | Aereo Taxi Autlan | AEREO AUTLAN | Mexico | |
| | TLE | Aero Util | AEROUTIL | Mexico | |
| | TLU | Aero Toluca Internactional | AEROTOLUCA | Mexico | |
| | TME | Aero Taxi del Centro de Mexico | TAXICENTRO | Mexico | |
| | TOC | Aerotropical | TROPICMEX | Mexico | |
| | TOH | Air Tomisko | TOMISKO CARGO | Serbia | |
| CG | TOK | Airlines PNG | BALUS | Papua New Guinea | |
| | TON | Aero Tonala | AEROTONALA | Mexico | |
| | TPB | Aero Tropical | AERO TROPICAL | Angola | |
| TY | TPC | Air Calédonie | AIRCAL | France | |
| | TPK | Air Horizon | TCHAD-HORIZON | Chad | |
| | TPO | Aero Taxi del Potosi | TAXI-POTOSI | Mexico | |
| | TQS | Aeroturquesa | AEROTURQUESA | Mexico | |
| | TRH | Airmark Aviation | TRANSTAR | United States | |
| FL | TRS | AirTran Airways | CITRUS | United States | defunct, last flight 12/30/2014, now part of Southwest Airlines |
| TS | TSC | Air Transat | AIR TRANSAT | Canada | |
| | TSQ | airtransse | AIRTRA | Japan | |
| | TTB | Aerolíneas Turísticas del Caribe | AERO TURISTICAS | Mexico | |
| | TTE | Avcenter | TETON | United States | |
| | TUN | Air Tungaru | TUNGARU | Kiribati | defunct |
| EC | TWN | Avialeasing Aviation Company | TWINARROW | Uzbekistan | |
| | TXD | Aerotaxis del Noroeste | TAXI OESTE | Mexico | |
| | TXF | Aerotaxis Alfe | ALFE | Mexico | |
| | TXI | Aereotaxis | AEREOTAXIS | Mexico | |
| | TZA | Aero Tomza | AERO TOMZA | Mexico | |
| | TZT | Air Zambezi | ZAMBEZI | Zimbabwe | |
| | UAG | Afra Airlines | AFRALINE | Ghana | |
| | UAR | Aerostar Airlines | AEROSTAR | Ukraine | |
| | UCK | Air Division of the Eastern Kazakhstan Region | GALETA | Kazakhstan | |
| U7 | UGA | Air Uganda | UGANDA | Uganda | |
| | UED | Air LA | AIR L-A | United States | |
| 6U | UKR | Air Ukraine | AIR UKRAINE | Ukraine | |
| | UMB | Air Umbria | AIR UMBRIA | Italy | |
| | UND | Atuneros Unidos de California | ATUNEROS UNIDOS | Mexico | |
| | USC | AirNet Express | STAR CHECK | United States | Renamed from US Check Airlines |
| | VNR | Avantair | AVANTAIR | United States | defunct |
| | VTG | Aviação Transportes Aéreos e Cargas | ATACARGO | Angola | |
| | WAS | Air-Watania | | Iraq | |
| | AAJ | Alfa Airlines | ALFA SUDAN | Sudan | |
| KO | AER | Alaska Central Express | ACE AIR | United States | |
| | AAK | Alaska Island Air | ALASKA ISLAND | United States | |
| KH | AAH | Aloha Air Cargo | ALOHA | United States | |
| AQ | AAH | Aloha Airlines | ALOHA | United States | defunct; former IATA code: TS |
| AA | AAL | American Airlines | AMERICAN | United States | |
| | XFS | American Flight Service Systems | | United States | |
| | XMG | AMS Group | | Russia | |
| WD* | AAN | Amsterdam Airlines | AMSTEL | Netherlands | Former IATA code: FH*. ICAO code and call sign no longer allocated |
| | ABI | Antigua and Barbuda Airways | Anair | Antigua and Barbuda | defunct |
| HO | DJA | Antinea Airlines | ANTINEA | Algeria | defunct |
| | EDY | Apollo Air Service | STOBART | United Kingdom | Was VLL Limited |
| | SRY | As-Aero | | Armenia | |
| OZ | AAR | Asiana Airlines | ASIANA | South Korea | |
| | XXX | ASL (Air Service Liege) | | Belgium | |
| AG | ABR | ASL Airlines Ireland | CONTRACT | Ireland | Former IATA Code: AG; former names: Hunting Air Cargo Airlines, Air Contractors |
| | XJA | Assistance Aeroportuaire de L'Aeroport de Paris | | France | |
| | AAE | Astec Air East | AIR EAST | United States | defunct |
| 8V | ACP | Astral Aviation | ASTRAL CARGO | Kenya | |
| | AAP | Astro Air International | ASTRO AIR | Philippines | defunct |
| | ATT | Attawasol Airlines | ATTAWASOL AIR | Libya | |
| XM | XME | Australian airExpress | AUS-CARGO | Australia | |
| AO | AUZ | Australian Airlines | AUSTRALIAN | Australia | Subsidiary merged with Qantas |
| | VAI | Avalair | AIR AVALAIR | Serbia | |
| XP | VXP | Avelo Airlines | AVELO | United States | Former ICAO code: CXP; former names: Casino Express Airlines, Xtra Airways |
| VE | AVE | Avensa | AVENSA | Venezuela | defunct |
| | VRT | Averitt Air Charter | AVERITT | United States | |
| | VSC | AVESCA | AVESCA | Colombia | defunct |
| | AJF | Avia Consult Flugbetriebs | AVIACONSULT | Austria | |
| | VTT | Avia Trans Air Transport | VIATRANSPORT | Sudan | |
| 6A | CHP | Aviacsa | AVIACSA | Mexico | |
| AV | AVA | Avianca | AVIANCA | Colombia | |
| A0 | MCJ | Avianca Argentina | JETMAC | Argentina | Owned by Synergy Group |
| O6 | ONE | Avianca Brasil | OCEAN AIR | Brazil | Owned by Synergy Group |
| 2K | GLG | Avianca Ecuador | GALAPAGOS | Ecuador | Aerolíneas Galápagos SA |
| | XAV | Aviaprom Enterprises | AVIAPROM | Russia | |
| | AVB | Aviation Beauport | BEAUPAIR | United Kingdom | |
| | AVQ | Aviation Services, Inc. | AQUILINE | United States | |
| | ACJ | Avicon | AVICHARTER | Kenya | |
| | VSR | Aviostart AS | AVIOSTART | Bulgaria | |
| V5 | VLI | Avolar Aerolíneas | AEROVOLAR | Mexico | defunct |
| | VSA | Avstar Aviation | STARBIRD | South Africa | |
| AD | AZU | Azul Linhas Aéreas Brasileiras | Azul | Brazil | |
| | BBF | B-Air Charter | SPEEDCHARTER | Germany | 2014 |
| CJ | CFE | BA CityFlyer | FLYER | United Kingdom | |
| TH | BRT | BA Connect | BRITISH | United Kingdom | defunct |
| | EFW | BA Euroflyer | GRIFFIN | United Kingdom | BA Euroflyer subsidiary based at London Gatwick |
| | BAC | BAC Leasing Limited | | United Kingdom | |
| B4 | BCF | BACH Flugbetriebsges | BACH | Austria | |
| | BOB | Backbone A/S | BACKBONE | Denmark | |
| J4 | BDR | Badr Airlines | BADR AIR | Sudan | |
| | BAE | BAE Systems | FELIX | United Kingdom | Corporate Air Travel |
| UP | BHS | Bahamasair | BAHAMAS | Bahamas | |
| | BAB | Bahrain Air BSC (Closed) | AWAL | Bahrain | |
| | BFW | Bahrain Defence Force | SUMMAN | Bahrain | |
| | BXA | Bahrain Executive Air Services | BEXAIR | Bahrain | |
| | BJA | Baja Air | BAJA AIR | Mexico | |
| 8Q* | BAJ | Baker Aviation | RODEO | United States | |
| | OGJ | Bakoji Airlines Services | BAKO AIR | Nigeria | |
| V9 | BTC | BAL Bashkirian Airlines | BASHKIRIAN | Russia | |
| | BEF | Balear Express | BALEAR EXPRESS | Spain | |
| | BLN | Bali International Air Service | BIAR | Indonesia | |
| | BAA | Balkan Agro Aviation | BALKAN AGRO | Bulgaria | |
| LZ | LAZ | Balkan Bulgarian Airlines | BALKAN | Bulgaria | defunct |
| | BHI | Balkh Airlines | SHARIF | Afghanistan | |
| | PNT | Balmoral Central Contracts | PORTNET | South Africa | |
| BQ | BTL | Baltia Air Lines | BALTIA | United States | Callsign changed from "BALTIA FLIGHT" in 2015 |
| | BLL | Baltic Airlines | BALTIC AIRLINES | Russia | |
| | BLT | Baltic Aviation | BALTAIR | United States | |
| | BJC | Baltic Jet Aircompany | BALTIC JET | Latvia | |
| | BTH | Baltijas Helicopters | BALTIJAS HELICOPTERS | Latvia | |
| | CPJ | Baltimore Air Transport | CORPJET | United States | |
| | EAH | Baltimore Airways | EASTERN | United States | |
| | BTK | Baltyka | BALTYKA | Ukraine | |
| QH | BAV | Bamboo Airways | BAMBOO | Vietnam | |
| QO | AJC | Bar Harbor Airlines | BAR HARBOR | United States | |
| | | BAX Global | | | |
| | AUJ | Business Flight Salzburg | AUSTROJET | Austria | |
| | CWR | Beijing City International Jet | CITY WORLD | China | |
| | BJV | Beijing Vistajet Aviation | BEIJING VISTA | China | |
| | BHK | Blu Halkin | BLUEHAKIN | United Kingdom | |
| | BXJ | Brixtel Group | BRIXTEL JET | United States | |
| | BYG | Bygone Aviation | BYGONE | United States | |
| | BBJ | Blue Air Lines | BLUE KOREA | South Korea | |
| | BCJ | Blue Jet Charters | BLUE BOY | Poland | |
| | BNA | Bun Air Corporation | BUN AIR | United States | |
| B3 | BTN | Bhutan Airlines | BHUTAN AIR | Bhutan | |
| | BAF | Belgian Air Force | BELGIAN AIRFORCE | Belgium | |
| | BAK | Blackhawk Airways | BLACKHAWK | United States | |
| L9 | BAL | Belle Air Europe | BELLEAIR EUROPE | Italy | Previously Britannia Airways |
| | BAL | Britannia Airways | BRITANNIA | United Kingdom | Defunct |
| | BAM | Business Air Services | BUSINESS AIR | Canada | |
| | BAN | British Antarctic Survey | PENGUIN | United Kingdom | |
| | BAR | Bradly Air (Charter) Services | BRADLEY | Canada | |
| | BAU | Bissau Airlines | AIR BISSAU | Guinea-Bissau | |
| | BAV | Bay Aviation Ltd | BAY AIR | Bangladesh | |
| BA | BAW | British Airways | SPEEDBIRD | United Kingdom | |
| | BAX | Best Aero Handling Ltd | | Russia | |
| | BAY | Bravo Airways | BRAVOAVIANCA | Ukraine | |
| | BBA | Bannert Air | BANAIR | Austria | |
| BG | BBC | Biman Bangladesh Airlines | BANGLADESH | Bangladesh | |
| BO | BBD | Bluebird Nordic | BLUE CARGO | Iceland | |
| | BBS | Beibars CJSC | BEIBARS | Kazakhstan | |
| | BBV | Bravo Airlines | BRAVO EUROPE | Spain | |
| BO | BBW | BB Airways | BEEBEE AIRWAYS | Nepal | |
| | BBZ | Bluebird Aviation | COBRA | Kenya | |
| SI | BCI | Blue Islands | BLUE ISLAND | United Kingdom | |
| EO | BCL | British Caribbean Airways | | United Kingdom | defunct |
| | BCR | British Charter | BACKER | United Kingdom | |
| | BCT | BCT Aviation | BOBCAT | United Kingdom | |
| | BCV | Business Aviation Center | BUSINESS AVIATION | Ukraine | |
| WX | BCY | CityJet | CITY JET | Ireland | |
| BZ | BDA | Blue Dart Aviation | BLUE DART | India | |
| JA | BON | B&H Airlines | Air Bosna | Bosnia and Herzegovina | |
| | BDF | Bissau Discovery Flying Club | BISSAU DISCOVERY | Guinea-Bissau | |
| | AYB | Belgian Army | BELGIAN ARMY | Belgium | |
| | BEA | Best Aviation Ltd | BEST AIR | Bangladesh | |
| | BED | Belgorod Air Enterprise | BELOGORYE | Russia | defunct |
| | BEH | Bel Air Helicopters | BLUECOPTER | Denmark | |
| | BEK | Berkut Air | BERKUT | Kazakhstan | |
| | BET | BETA - Brazilian Express Transportes Aéreos | BETA CARGO | Brazil | |
| | BFC | Basler Flight Service | BASLER | United States | |
| | BFG | Bear Flight | BEARFLIGHT | Sweden | |
| J4 | BFL | Buffalo Airways | BUFFALO | Canada | |
| | BFO | Bombardier | BOMBARDIER | Canada | |
| | BFR | Burkina Airlines | BURKLINES | Burkina Faso | |
| | BFS | Business Flight Sweden | BUSINESS FLIGHT | Sweden | |
| 8H | BGH | BH Air | BALKAN HOLIDAYS | Bulgaria | |
| | BGI | British Gulf International | BRITISH GULF | São Tomé and Príncipe | |
| | BGK | British Gulf International-Fez | GULF INTER | Kyrgyzstan | |
| A8 | BGL | Benin Golf Air | BENIN GOLF | Benin | |
| | BGM | Bugulma Air Enterprise | BUGAVIA | Russia | |
| | BGR | Budget Air Bangladesh | BUDGET AIR | Bangladesh | |
| | BGT | Bergen Air Transport | BERGEN AIR | Norway | |
| U4 | BHA | Buddha Air | BUDDHA AIR | Nepal | |
| UH | BHL | Bristow Helicopters | BRISTOW | United Kingdom | |
| | BHN | Bristow Helicopters Nigeria | BRISTOW HELICOPTERS | Nigeria | |
| | BHO | Bhoja Airlines | BHOJA | Pakistan | |
| 4T | BHP | Belair Airlines | BELAIR | Switzerland | |
| | BHR | Bighorn Airways | BIGHORN AIR | United States | |
| | BHT | Bright Air | BRIGHTAIR | Netherlands | ICAO code and call sign no longer allocated |
| E6 | | Bringer Air Cargo Taxi Aéreo | | Brazil | |
| | BHY | Bosphorus European Airways | BOSPHORUS | Turkey | |
| | BID | Binair | BINAIR | Germany | |
| | BIG | Big Island Air | BIG ISLE | United States | |
| BS | BIH | British International Helicopters | BRINTEL | United Kingdom | |
| | BIL | Billund Air Center | BILAIR | Denmark | |
| | BIN | Boise Interagency Fire Center | BISON-AIR | United States | |
| | BIO | Bioflight A/S | BIOFLIGHT | Denmark | |
| | BIR | Bird Leasing | BIRD AIR | United States | |
| | BIZ | Bizjet Ltd | BIZZ | United Kingdom | |
| | BJS | Business Jet Solutions | SOLUTION | United States | |
| B4 | BKA | Bankair | BANKAIR | United States | |
| | BKF | BF-Lento OY | BAKERFLIGHT | Finland | |
| | BKK | Blink | BLINKAIR | United Kingdom | |
| | BKJ | Barken International | BARKEN JET | United States | |
| PG | BKP | Bangkok Airways | BANGKOK AIR | Thailand | |
| | BKV | Bukovyna | BUKOVYNA | Ukraine | |
| | BLB | Blue Bird Aviation | BLUEBIRD SUDAN | Sudan | |
| | BLC | Bellesavia | BELLESAVIA | Belarus | |
| | BLE | Blue Line | BLUE BERRY | France | |
| KF | BLF | Blue1 | BLUEFIN | Finland | |
| | BLG | Belgavia | BELGAVIA | Belgium | |
| | BLH | Blue Horizon Travel Club | BLUE HORIZON | United States | |
| | BLJ | Blue Jet | BLUEWAY | Spain | |
| | BLM | Blue Sky Airlines | BLUE ARMENIA | Armenia | defunct |
| JV | BLS | Bearskin Lake Air Service | BEARSKIN | Canada | |
| B3 | BLV | Bellview Airlines | BELLVIEW AIRLINES | Nigeria | |
| BD | BMA | BMI | MIDLAND | United Kingdom | defunct |
| 2T | BMA | BermudAir | GOSLING | Bermuda |
| BM | BMR | BMI Regional | MIDLAND | United Kingdom | |
| | BMD | British Medical Charter | BRITISH MEDICAL | United Kingdom | |
| | BME | Briggs Marine Environmental Services | BRIGGS | United Kingdom | |
| | BMH | Bristow Masayu Helicopters | MASAYU | Indonesia | |
| WW | BMI | Bmibaby | BABY | United Kingdom | defunct |
| CH | BMJ | Bemidji Airlines | BEMIDJI | United States | |
| 5Z | BML | Bismillah Airlines | BISMILLAH | Bangladesh | IATA code in use by another company |
| | BMN | Bowman Aviation | BOWMAN | United States | |
| | BMW | BMW | BMW-FLIGHT | Germany | |
| | BMX | Banco de Mexico | BANXICO | Mexico | |
| | BND | Bond Offshore Helicopters | BOND | United Kingdom | |
| | BNE | Benina Air | BENINA AIR | Libya | |
| BN | BNF | Braniff International Airways | Braniff | United States | defunct |
| | BNG | BN Group Limited | VECTIS | United Kingdom | |
| | BNJ | Air Service Liège (ASL) | JET BELGIUM | Belgium | |
| | BNL | Blue Nile Ethiopia Trading | NILE TRADING | Ethiopia | |
| | BNR | Bonair Aviation | BONAIR | Canada | |
| | BNS | Bancstar - Valley National Corporation | BANCSTAR | United States | |
| | BNT | Bentiu Air Transport | BENTIU AIR | Sudan | |
| | BNV | Benane Aviation Corporation | BENANE | Mauritania | |
| | BNW | British North West Airlines | BRITISH NORTH | United Kingdom | |
| | BOD | Bond Air Services | UGABOND | Uganda | |
| | BOA | Boniair | KUMANOVO | North Macedonia | |
| AB | BNZ | Bonza | BONZA | Australia | Defunct |
| | BOE | Boeing | BOEING | United States | |
| | BOF | Bordaire | BORDAIR | Canada | |
| | BOO | Bookajet Limited | BOOKAJET | United Kingdom | |
| BO | BOU | Bouraq Indonesia Airlines | BOURAQ | Indonesia | |
| BV | BPA | Blue Panorama Airlines | BLUE PANORAMA | Italy | |
| | BPK | Berkhut ZK | VENERA | Kazakhstan | |
| | BPO | Bundespolizei-Fliegertruppe | PIROL | Germany | |
| | BPS | Budapest Aircraft Services/Manx2 | BASE | Hungary | |
| | BPT | Bonus Aviation | BONUS | United Kingdom | |
| | BPX | British Petroleum Exploration | | Colombia | |
| 7R | BRB | BRA-Transportes Aéreos | BRA-TRANSPAEREOS | Brazil | |
| | BRD | Brock Air Services | BROCK AIR | Canada | |
| | BRE | Breeze Ltd | AVIABREEZE | Ukraine | |
| 8E | BRG | Bering Air | BERING AIR | United States | |
| | BRK | Briansk State Air Enterprise | BRIANSK-AVIA | Russia | |
| | BRN | Branson Airlines | BRANSON | United States | |
| | BRO | BASE Regional Airlines | COASTRIDER | Netherlands | ICAO code in use by another company, call sign no longer allocated |
| | BRS | Brazilian Air Force | BRAZILIAN AIR FORCE | Brazil | |
| TH | BRT | British Regional Airlines | BRITISH | United Kingdom | defunct |
| B2 | BRU | Belavia Belarusian Airlines | BELARUS AVIA | Belarus | |
| | BRV | Bravo Air Congo | BRAVO | Democratic Republic of the Congo | defunct |
| | BRW | Bright Aviation Services | BRIGHT SERVICES | Bulgaria | |
| | BRX | Buffalo Express Airlines | BUFF EXPRESS | United States | |
| | BRY | Burundayavia | BURAIR | Kazakhstan | |
| | BSC | Bistair - Fez | BIG SHOT | Kyrgyzstan | |
| | BSD | Blue Star Airlines | AIRLINES STAR | Mexico | |
| | BSI | Brasair Transportes Aéreos | BRASAIR | Brazil | |
| | BSJ | Blue Swan Aviation | BLUE SWAN | United Kingdom | ICAO Code and callsign (BSJ/BLUE SWAN) withdrawn |
| | BSM | Blue Sky Aviation | | Lebanon | |
| | BSS | Bissau Aero Transporte | BISSAU AIRSYSTEM | Guinea-Bissau | |
| | BST | Best Air | TUNCA | Turkey | |
| | BSW | Blue Sky Airways | SKY BLUE | Czech Republic | |
| GQ | BSY | Big Sky Airlines | BIG SKY | United States | |
| | BTI | Air Baltic | Air Baltic | Latvia | |
| ID | BTK | Batik Air | BATIK | Indonesia | |
| 4B | BTQ | Boutique Air | BOUTIQUE | United States | |
| | BTR | Botir-Avia | BOTIR-AVIA | Kyrgyzstan | |
| | BTT | BT-Slavuta | BEETEE-SLAVUTA | Ukraine | |
| Y6 | BTV | Batavia Air | BATAVIA | Indonesia | As of June 1, 2010, IATA code changed to Y6. |
| L9 | BTZ | Bristow U.S. LLC | BRISTOW | United States | |
| 1T | BUC | Bulgarian Air Charter | BULGARIAN CHARTER | Bulgaria | |
| | BUL | Blue Airlines | BLUE AIRLINES | Democratic Republic of the Congo | |
| BU | BUN | Buryat Airlines Aircompany | BURAL | Russia | |
| | BUZ | Buzz Stansted | BUZZ | United Kingdom | |
| | BVA | Buffalo Airways | BUFFALO AIR | United States | |
| | BVC | Bulgarian Aeronautical Centre | BULGARIAN WINGS | Bulgaria | |
| | BVN | Baron Aviation Services | SHOW-ME | United States | |
| J8 | BVT | Berjaya Air | BERJAYA | Malaysia | |
| B3 | BVU | Bellview Airlines, Sierra Leone | BELLVIEW AIRLINES | Sierra Leone | |
| | BWD | Bluewest Helicopters-Greenland | BLUEWEST | Denmark | |
| QW | BWG | Blue Wings | BLUE WINGS | Germany | defunct |
| | BWI | Blue Wing Airlines | BLUE TAIL | Suriname | |
| | BWL | British World Airlines | BRITWORLD | United Kingdom | |
| | BXH | Bar XH Air | PALLISER | Canada | |
| SN | BXI | Brussels Airlines | XENIA | Belgium | defunct as Brussels International Airlines in 2001 |
| | BYA | Berry Aviation | BERRY | United States | |
| | BYC | Cambodia Bayon Airlines | Bayon Air | Cambodia | |
| | BYF | San Carlos Flight Center | BAY FLIGHT | United States | |
| | BYL | Bylina Joint-Stock Company | BYLINA | Russia | |
| | BYR | Berytos Airlines | | Lebanon | |
| | BYE | Bayu Indonesia Air | BAYU | Indonesia | |
| | BZA | Bizair Fluggesellschaft | BERLIN BEAR | Germany | |
| DB | BZH | Brit Air | BRITAIR | France | |
| | BZZ | Butane Buzzard Aviation Corporation | BUZZARD | United Kingdom | |
| JD | CBJ | Beijing Capital Airlines | CAPITAL JET | China | |
| | CKM | BKS Air (Rivaflecha) | COSMOS | Spain | |
| | CLF | Bristol Flying Centre | CLIFTON | United Kingdom | |
| | CLN | Barnes Olsen Aeroleasing | SEELINE | United Kingdom | |
| E9 | CXS | Boston-Maine Airways | CLIPPER CONNECTION | United States | Pan Am Clipper Connection Pan Am III |
| SN | BEL | Brussels Airlines | BEE-LINE | Belgium | |
| | EBA | Bond Aviation | BOND AVIATION | Italy | |
| | EXB | Brazilian Army Aviation | BRAZILIAN ARMY | Brazil | |
| | EXP | Business Express Delivery | EXPRESS AIR | Canada | |
| | FOS | Bel Limited | | Russia | |
| | GAA | Business Express | BIZEX | United States | |
| | HAW | Bangkok Aviation Center | THAI HAWK | Thailand | |
| | HAX | Benair | SCOOP | Norway | |
| NT | IBB | Binter Canarias | BINTER | Spain | |
| | IRJ | Bonyad Airlines | BONYAD AIR | Iran | |
| | IVR | Burundaiavia | RERUN | Kazakhstan | |
| 0B | BLA | Blue Air | BLUE AIR | Romania | |
| KJ | LAJ | British Mediterranean Airways | BEE MED | United Kingdom | defunct |
| | LBY | Belle Air | ALBAN-BELLE | Albania | |
| | LED | Blom Geomatics | SWEEPER | Norway | |
| | LTL | Benin Littoral Airways | LITTORAL | Benin | |
| | LXJ | Bombardier Business Jet Solutions | FLEXJET | United States | |
| FB | LZB | Bulgaria Air | FLYING BULGARIA | Bulgaria | |
| | MBR | Brazilian Navy Aviation | BRAZILIAN NAVY | Brazil | |
| 8N | NKF | Barents AirLink | NORDFLIGHT | Sweden | previously Nordkalottflyg |
| | NYB | Belgian Navy | BELGIAN NAVY | Belgium | |
| | OTA | Business Aviators | OUTLAW | United States | 2014 |
| | OUF | Beijing Eofa International Jet | ELEMENT | China | 2014 |
| | PEB | Benders Air | PALEMA | Sweden | |
| | POI | BGB Air | BOJBAN | Kazakhstan | |
| | PPS | Butte Aviation | PIPESTONE | United States | |
| | PVO | Bearing Supplies Limited | PROVOST | United Kingdom | |
| | RHD | Bond Air Services | RED HEAD | United Kingdom | |
| | RLR | Business Airfreight | RATTLER | United States | |
| | RRS | Boscombe Down DERA (Formation) | BLACKBOX | United Kingdom | |
| | SCJ | Business Jet Sweden | SCANJET | Sweden | |
| | SHT | British Airways Shuttle | SHUTTLE | United Kingdom | BA domestic services |
| | SKH | British Sky Broadcasting | SKYNEWS | United Kingdom | |
| | TBL | Bell Aliant Regional Communications | TELCO | Canada | |
| | TXB | Bell Helicopter Textron | TEXTRON | Canada | |
| | UKA | Buzzaway Limited | UKAY | United Kingdom | |
| | VLX | Biz Jet Charter | AVOLAR | United States | |
| | VOL | Blue Chip Jet | BLUE SPEED | Sweden | |
| | WFD | BAE Systems | AVRO | United Kingdom | Woodford Flight Test |
| | WTN | BAE Systems | TARNISH | United Kingdom | Warton Military Flight Ops |
| | XBO | Baseops International | | United States | |
| | XDA | Bureau Veritas | | France | |
| | XMS | British Airways Santa | SANTA | United Kingdom | Christmas charter flights |
| | ZBA | Boskovic Air Charters Limited | BOSKY | Kenya | |
| | JMP | Businesswings | JUMP RUN | Germany | |
| OB | BOV | Boliviana de Aviación | BOLIVIANA | Bolivia | |
| YB | BRJ | Borajet | BORA JET | Turkey | |
| MX | MXY | Breeze Airways | MOXY | United States | |
| VL | LHX | City Airlines | CITYAIR | Germany | LH subsidiary Allocated in 2023 |
| | SRJ | C Air Jet Airlines | SYRJET | Syria | |
| | TIP | C and M Aviation | TRANSPAC | United States | |
| | ORO | C N Air | CAPRI | Spain | |
| | RWG | C&M Airways | RED WING | United States | |
| | RMU | C.S.P., Societe | AIR-MAUR | Mauritania | |
| | CJZ | Caliber Jet | CALIBER JET | United States | |
| 4A | DYN | California Pacific Airlines | AERODYNAMICS | United States | defunct |
| QC | CRC | Camair-Co | CAMAIRCO | Cameroon | |
| | QAI | Conquest Air | CHICKPEA | United States | 2014 |
| | CBH | Corporate Eagle Management Services | CLUB HOUSE | United States | Allocated in 2014 |
| | CRF | Croix Rouge Francais | CROIX ROUGE | France | 2014 |
| | CAA | Civil Aviation Authority of the Czech Republic | INSPECTOR | Czech Republic | |
| | BKR | Civil Air Patrol South Carolina Wing | BOX KAR | United States | |
| | BFN | Compagnie Nationale Naganagani | | Burkino Faso | |
| | AWX | Civil Aviation Authority Directorate of Airspace Policy | ALLWEATHER | United Kingdom | |
| | BBN | Civil Aviation Authority Airworthiness Division | BRABAZON | United Kingdom | |
| | ATQ | CHC Helicopters Nigeria | COLIBRI | Nigeria | |
| | APL | Corporativo Aereo Principal | AEREO PRINCIPAL | Mexico | |
| | AIO | Chief of Staff, United States Air Force | AIR CHIEF | United States | |
| | AID | Christian Konig - Century Airbirds | CENTURY AIRBIRD | Austria | |
| | | Cambridge Recurrent Training | CAMBRIDGE | United Kingdom | |
| | | California Department of Forestry and Fire Protection | CALFIRE | United States | |
| | | Careflight Queensland | SAMARITAN | Australia | |
| | | Castle Air Charter | CASTLEFILM | United Kingdom | |
| | | Challenges Aviation | TIGER | United Kingdom | |
| | | Challenges Limited | HERITAGE | United Kingdom | |
| | | Cheqair | ASTON | United Kingdom | |
| | | Clacton Aero Club | CLASSIC WINGS | United Kingdom | |
| | | Coral Sun Airways | CORAL SUN | Kiribati | |
| | | Cowan Group | COWAN | United States | |
| | SMW | Carpatair Flight Service | SMART WINGS | Romania | Was Carpatair Flight Training |
| | CCL | Cambodia Airlines | ANGKOR WAT | Cambodia | |
| KR | KME | Cambodia Airways | GIANT IBIS | Cambodia | |
| | CCB | Caricom Airways | DOLPHIN | Barbados | |
| | CYH | China Southern Airlines Henan | YUHAO | China | |
| | CFB | Chongqing Forebase General Aviation | FOREBASE | China | |
| | XCA | Colt Transportes Aereos | COLT | Brazil | |
| | GCY | CHC Global Operations International | HELIBIRD | United Kingdom | |
| | AUN | Common Sky | COMMON SKY | Austria | |
| | CBI | Cabi | CABI | Ukraine | |
| | CPI | Compagnia Aeronautica Italiana | AIRCAI | Italy | |
| 5C | ICL | Challenge Airlines IL | CAL | Israel | ex CAL-Cargo Air Lines |
| | CMR | CAM Air Management | CAMEO | United Kingdom | |
| | CTZ | CATA Línea Aérea | CATA | Argentina | |
| | CCF | CCF Manager Airline | TOMCAT | Germany | |
| | CED | CEDTA (Compañía Ecuatoriana De Transportes Aéreos) | CEDTA | Ecuador | |
| | HBI | CHC Denmark | HELIBIRD | Denmark | |
| | HEM | CHC Helicopter | HEMS | Australia | |
| AW | SCH | CHC Airways | SCHREINER | Netherlands | formerly Schreiner Airways. ICAO code in use by another company, call sign no longer allocated |
| | HKS | CHC Helikopter Service | HELIBUS | Norway | |
| | VCI | CI-Tours | CI-TOURS | Ivory Coast | |
| | CKC | CKC Services | | United States | |
| | CMZ | CM Stair | CEE-EM STAIRS | Mauritania | |
| | CNT | Centre national d'études des télécommunications - C.N.E.T. | KNET | France | |
| | OAP | COAPA AIR | COAPA | Mexico | |
| | PDR | COMAV | SPEEDSTER | Namibia | |
| | CRH | CRI Helicopters Mexico | HELI-MEX | Mexico | |
| | IRO | CSA Air | IRON AIR | United States | |
| | CSE | CSE Aviation | OXFORD | United Kingdom | |
| | CTQ | CTK Network Aviation | CITYLINK | Ghana | |
| | CBR | Cabair College of Air Training | CABAIR | United Kingdom | |
| | CVE | Cabo Verde Express | KABEX | Cape Verde | |
| | CWD | Caernarfon Airworld | AMBASSADOR | United Kingdom | |
| | CXE | Caicos Express Airways | CAICOS | Turks and Caicos Islands | |
| | CCE | Cairo Air Transport Company | | Egypt | |
| | CGC | Cal Gulf Aviation | CAL-GULF | São Tomé and Príncipe | |
| | REZ | Cal-West Aviation | CAL AIR | United States | |
| | CSL | California Air Shuttle | CALIFORNIA SHUTTLE | United States | |
| 3C | CMV | Calima Aviación | CALIMA | Spain | |
| MO | CAV | Calm Air | CALM AIR | Canada | |
| R9 | CAM | Camai Air | AIR CAMAI | United States | Village Aviation |
| K6 | KHV | Cambodia Angkor Air | ANGKOR AIR | Cambodia | |
| UY | UYC | Cameroon Airlines | CAM-AIR | Cameroon | defunct |
| | HSO | Campania Helicopteros De Transporte | HELIASTURIAS | Spain | |
| C6 | CJA | CanJet | CANJET | Canada | |
| | PIL | Canada Jet Charters | PINNACLE | Canada | |
| CP | CDN | Canadian Airlines | CANADIAN | Canada | defunct |
| | CTG | Canadian Coast Guard | CANADIAN COAST GUARD | Canada | |
| | HIA | Canadian Eagle Aviation | HAIDA | Canada | |
| | CFC | Canadian Forces | CANFORCE | Canada | |
| | BZD | Canadian Global Air Ambulance | BLIZZARD | Canada | ICAO Code and callsign no longer allocated |
| | CDN | Canadian Helicopters | CANADIAN | Canada | |
| | TKR | Canadian Interagency Forest Fire Centre | TANKER | Canada | ICAO Code and callsign no longer allocated |
| | XNC | Canadian National Telecommunications | | Canada | ICAO Code and callsign no longer allocated |
| 7F | AKT | Canadian North | ARCTIC | Canada | Air Norterra |
| CP | CPC | Canadian Pacific Airlines | EMPRESS | Canada | ICAO Code and callsign no longer allocated |
| | CDR | Canadian Regional Airlines | CANADIAN REGIONAL | Canada | ICAO Code and callsign no longer allocated |
| | CWH | Canadian Warplane Heritage Museum | WARPLANE HERITAGE | Canada | |
| W2 | CWA | Canadian Western Airlines | CANADIAN WESTERN | Canada | |
| | CWW | Canair | CANAIR | China | |
| | CUI | Cancun Air | CAN-AIR | Mexico | |
| 9K | KAP | Cape Air | CAIR | United States | |
| | CTO | Cape Air Transport | | Australia | |
| | SEM | Cape Central Airways | SEMO | United States | |
| | CMY | Cape Smythe Air | CAPE SMYTHE AIR | United States | |
| | CPX | Capital Air Service | CAPAIR | United States | |
| | CPD | Capital Airlines | CAPITAL DELTA | Kenya | |
| | NCP | Capital Airlines Limited | CAPITAL SHUTTLE | Nigeria | |
| PT | CCI | Capital Cargo International Airlines | CAPPY | United States | Allocation deleted 2013 |
| | CCQ | Capital City Air Carriers | CAP CITY | United States | |
| | EGL | Capital Trading Aviation | PRESTIGE | United Kingdom | |
| | CEX | Capitol Air Express | CAPITOL EXPRESS | United States | |
| | CWZ | Capitol Wings Airline | CAPWINGS | United States | |
| | VAN | Caravan Air | CAMEL | Mauritania | |
| | CWN | Cardiff Wales Flying Club | CAMBRIAN | United Kingdom | |
| | FVA | Cardinal/Air Virginia | AIR VIRGINIA | United States | |
| | GOL | Cardolaar | CARGOLAAR | Namibia | |
| | CDI | Cards Air Services | CARDS | Philippines | |
| | CFH | CareFlight | CARE FLIGHT | Australia | |
| | CDM | Carga Aérea Dominicana | CARGA AEREA | Dominican Republic | |
| | EST | Carga Express Internacional | CARGAINTER | Mexico | |
| GG | GGC | Cargo 360 | LONG-HAUL | United States | |
| | MCX | Cargo Express | MAURICARGO | Mauritania | |
| | CRV | Cargo Ivoire | CARGOIV | Ivory Coast | |
| | CLM | Cargo Link (Caribbean) | CARGO LINK | Barbados | |
| P3 | CLU | Cargo Logic Air | FIREBIRD | United Kingdom | |
| | CTW | Cargo Three | THIRD CARGO | Panama | |
| 2G | CRG | Cargoitalia | WHITE PELICAN | Italy | |
| W8 | CJT | Cargojet Airways | CARGOJET | Canada | |
| CV | CLX | Cargolux | CARGOLUX | Luxembourg | |
| C8 | ICV | Cargolux Italia | CARGO MED | Italy | |
| | CGM | Cargoman | HOTEL CHARLIE | Oman | |
| | DEL | Carib Aviation | RED TAIL | Antigua and Barbuda | |
| | BCB | Carib Express | WAVEBIRD | Barbados | |
| | PWD | CARIBAIR | CARIBAIR | Dominican Republic | |
| | DCC | Caribbean Air Cargo | CARICARGO | Barbados | |
| | CLT | Caribbean Air Transport | CARIBBEAN | Netherlands | ICAO Code and callsign no longer allocated |
| | CLT | Club Aerocelta de Vuelo Con Motor | | Spain | |
| BW | BWA | Caribbean Airlines | CARIBBEAN AIRLINES | Trinidad and Tobago | |
| | IQQ | Caribbean Airways | CARIBJET | Barbados | |
| | CSX | Choice Airways | CHOICE AIR | United States | |
| | TLC | Caribbean Express | CARIB-X | United States | |
| 8B | GFI | Caribbean Star Airlines | CARIB STAR | Antigua and Barbuda | |
| | CRB | Caricom Airways | CARIBBEAN COMMUTER | Suriname | |
| | CRT | Caribintair | CARIBINTAIR | Haiti | |
| | CVG | Carill Aviation | CARILL | United Kingdom | |
| V3 | KRP | Carpatair | CARPATAIR | Romania | |
| | CRR | Carranza | CARRANZA | Chile | defunct |
| | ULS | Carroll Air Service | ULSTER | United States | |
| | CMT | Casement Aviation | CASEMENT | United States | |
| | CSO | Casino Airline | CASAIR | United States | |
| | CSP | Casper Air Service | CASPER AIR | United States | |
| RV | CPN | Caspian Airlines | CASPIAN | Iran | |
| | CSJ | Castle Aviation | CASTLE | United States | |
| | CAZ | Cat Aviation | EUROCAT | Switzerland | |
| | CBT | Catalina Flying Boats | CATALINA AIR | United States | |
| | TEX | Catex | CATEX | France | |
| KA | HDA | Cathay Dragon | DRAGON | Hong Kong | defunct IATA Code transferred to Aero Nomad Airlines |
| CX | CPA | Cathay Pacific | CATHAY | Hong Kong | |
| | CJR | Caverton Helicopters | CAVERTON AIR | Nigeria | |
| KX | CAY | Cayman Airways | CAYMAN | Cayman Islands | |
| 5J | CEB | Cebu Pacific | CEBU | Philippines | |
| | CIL | Cecil Aviation | CECIL | United Kingdom | |
| | CEG | Cega Aviation | CEGA | United Kingdom | |
| | CEC | Celtic Airways | CELTAIR | United Kingdom | |
| | CWE | Celtic West | CELTIC | United Kingdom | |
| | CEV | Centre d'Essais en Vol | CENTEV | France | |
| | CNL | Centennial Airlines | WYO-AIR | United States | |
| | CNS | Cobalt Air LLC | CHRONOS | United States | |
| | CVO | Center Vol | CENTERVOL | Spain | |
| | CTS | Center-South | CENTER-SOUTH | Russia | |
| | CET | Centrafrican Airlines | CENTRAFRICAIN | Central African Republic | |
| | CAX | Central Air Express | CENTRAL EXPRESS | Democratic Republic of the Congo | |
| | CTL | Central Airlines | CENTRAL COMMUTER | United States | |
| | CNY | Central Airways | CENTRAL LEONE | Sierra Leone | |
| | ACN | Central American Airlines | AEROCENTRO | Nicaragua | |
| | YOG | Central Aviation | YOGAN AIR | United States | |
| | DRN | Central De Discos De Reynosa | DISCOS REYNOSA | Mexico | |
| 2C | CMA | CMA-CGM AIRCARGO | FRENCH CARGO | France | |
| | CHA | Central Flying Service | CHARTER CENTRAL | United States | |
| | CEM | Central Mongolia Airways | CENTRAL MONGOLIA | Mongolia | |
| 9M | GLR | Central Mountain Air | GLACIER | Canada | |
| | CQC | Central Queensland Aviation College | | Australia | |
| | CSI | Central Skyport | SKYPORT | United States | |
| | CLW | Centralwings | CENTRALWINGS | Poland | |
| | DTV | Centre Airlines | DUTCH VALLEY | United States | |
| | CGS | Centre of Applied Geodynamica | GEO CENTRE | Russia | |
| J7 | CVC | Centre-Avia | AVIACENTRE | Russia | |
| | CCV | Centro De Helicopteros Corporativos | HELICORPORATIVO | Mexico | |
| | ACF | Centro de Formación Aeronáutica de Canarias | FORCAN | Spain | |
| WE | CWC | Centurion Air Cargo | CHALLENGE CARGO | United States | |
| | URY | Century Aviation | CENTURY AVIA | Mexico | |
| | HAI | Century Aviation International | | Canada | |
| | XAD | Certified Air Dispatch | | United States | |
| | CER | Cetraca Aviation Service | CETRACA | Democratic Republic of the Congo | |
| | IRU | Chabahar Airlines | CHABAHAR | Iran | |
| GM | GSW | Chair Airlines | EIGER | Switzerland | |
| | CLG | Chalair Aviation | CHALLAIR | France | |
| OP | CHK | Chalk's International Airlines | CHALKS | United States | |
| | CLS | Challenge Air Transport | AIRISTO | Germany | |
| | CHS | Challenge Aviation | CHALLENGE AVIATION | Australia | |
| | OFF | Challenge International Airlines | CHALLENGE AIR | United States | |
| | CHG | Challenge Airlines BE | Challenge | Belgium | |
| | CPH | Champagne Airlines | CHAMPAGNE | France | |
| MG | CCP | Champion Air | CHAMPION AIR | United States | |
| | NCH | Chanchangi Airlines | CHANCHANGI | Nigeria | |
| 2Z | CGN | Chang An Airlines | CHANGAN | China | |
| | CHN | Channel Island Aviation | CHANNEL | United States | |
| | WML | Chantilly Air | MARLIN | United States | |
| | CPL | Chaparral Airlines | CHAPARRAL | United States | |
| S8 | CSU | Chari Aviation Services | CHARI SERVICE | Chad | |
| | CAH | Charlan Air Charter | CHARLAN | South Africa | ICAO Code and callsign no longer allocated |
| | HMD | Charlie Hammonds Flying Service | HAMMOND | United States | |
| | CGD | Charlotte Air National Guard | | United States | |
| | CHW | Charter Air | CHARTER WIEN | Austria | |
| | HRT | Chartright Air | CHARTRIGHT | Canada | |
| RP* | CHQ | Chautauqua Airlines | CHAUTAUQUA | United States | Was US* |
| | CBB | Cheboksary Airenterprise JSC | CHEBAIR | Russia | |
| | CHM | Chemech Aviation | | Pakistan | |
| | CHZ | Cherline | CHERL | Russia | |
| | CMK | Chernomor-Avia | CHERAVIA | Russia | |
| | CBM | Cherokee Express | BLUE MAX | United States | |
| | CCY | Cherry Air | CHERRY | United States | |
| | CAB | Chesapeake Air Service | CHESAPEAKE AIR | United States | |
| | CVR | Chevron U.S.A | CHEVRON | United States | |
| | CYA | Cheyenne Airways | CHEYENNE AIR | United States | |
| | CGO | Chicago Air | WILD ONION | United States | |
| C8 | WDY | Chicago Jet Group | WINDY CITY | United States | |
| | RAT | Chief Rat Flight Services | RIVERRAT | South Africa | defunct |
| | CCH | Chilchota Taxi Aéreo | CHILCHOTA | Mexico | |
| | DES | Chilcotin Caribou Aviation | CHILCOTIN | Canada | |
| | CAD | Chilliwack Aviation | CHILLIWACKAIR | Canada | |
| | ETN | Chim-Nir Aviation | CHIMNIR | Israel | |
| CI | CAL | China Airlines | DYNASTY | Taiwan | |
| CK | CKK | China Cargo Airlines | CARGO KING | China | |
| MU | CES | China Eastern Airlines | CHINA EASTERN | China | |
| G5 | HXA | China Express Airlines | CHINA EXPRESS | China | |
| | CFA | China Flying Dragon Aviation | FEILONG | China | |
| | CTH | China General Aviation Corporation | TONGHANG | China | |
| | CAG | China National Aviation Corporation | CHINA NATIONAL | China | |
| CJ | CBF | China Northern Airlines | CHINA NORTHERN | China | defunct. |
| WH | CNW | China Northwest Airlines | CHINA NORTHWEST | China | defunct |
| | CHC | China Ocean Helicopter Corporation | CHINA HELICOPTER | China | |
| 8Y | CYZ | China Postal Airlines | CHINA POST | China | |
| CZ | CSN | China Southern Airlines | CHINA SOUTHERN | China | |
| | CXN | China Southwest Airlines | CHINA SOUTHWEST | China | defunct |
| KN | CUA | China United Airlines | LIANHANG | China | |
| XO | CXH | China Xinhua Airlines | XINHUA | China | |
| 3Q | CYH | China Yunnan Airlines | YUNNAN | China | defunct |
| | CGU | Chinguetti Airlines | CHINGUETTI | Mauritania | |
| | CEP | Chipola Aviation | CHIPOLA | United States | |
| | CPW | Chippewa Air Commuter | CHIPPEWA-AIR | United States | |
| X7 | CHF | Chitaavia | CHITA | Russia | |
| OQ | CQN | Chongqing Airlines | CHONG QING | China | |
| | CAS | Christman Air System | CHRISTMAN | United States | |
| | OEC | Christophorus Flugrettungsverein | CHRISTOPHORUS | Austria | |
| | CHO | Chrome Air Services | CHROME AIR | United States | |
| | CHU | Church Aircraft | CHURCHAIR | United States | |
| A2 | CIU | Cielos Airlines | CIELOS | Peru | |
| QI | CIM | Cimber Sterling | CIMBER | Denmark | |
| C7 | CIN | Cinnamon Air | CINNAMON | Sri Lanka | |
| | RRU | Cirrus | HELICIRRUS | Chile | defunct |
| | NTS | Cirrus Air | NITE STAR | United States | |
| C9 | RUS | Cirrus Airlines | CIRRUS AIR | Germany | defunct |
| | JTI | Cirrus Middle East | | Lebanon | |
| | FIV | CitationAir | FIVE STAR | United States | |
| | XCX | Citibank | | United States | |
| | HZX | Citic General Aviation | ZHONGXIN | China | |
| | SDR | City Airline | SWEDESTAR | Sweden | |
| G3 | CIX | City Connexion Airlines | CONNEXION | Burundi | defunct |
| | XBG | City of Bangor | | United States | |
| WX | BCY | CityJet | CITY-IRELAND | Ireland | |
| | CAQ | Cityair (Chester) Limited | AIR CHESTER | United Kingdom | |
| | CII | Cityfly | CITYFLY | Italy | |
| CJ | CFE | CityFlyer Express | FLYER | United Kingdom | Defunct, ICAO code in use by BA CityFlyer |
| | CNB | Cityline Hungary | CITYHUN | Hungary | |
| | HSR | Citylink Airlines | HOOSIER | United States | |
| | CIW | Civair Airways | CIVFLIGHT | South Africa | |
| | CAP | Civil Air Patrol | CAP | United States | |
| CT | CAT | Civil Air Transport | Mandarin | Taiwan | defunct |
| | CIA | Civil Aviation Authority | CALIMERA | Slovakia | |
| | CIV | Civil Aviation Authority of New Zealand | CIVAIR | New Zealand | |
| | CBA | Civil Aviation Inspectorate of the Czech Republic | CALIBRA | Czech Republic | |
| | FMC | Claessens International Limited | CLAESSENS | United Kingdom | |
| | CLK | Clark Aviation | CLARKAIR | United States | |
| | CSF | Clasair | CALEDONIAN | United Kingdom | |
| | CLY | Clay Lacy Aviation | CLAY-LACY | United States | |
| | CGK | Click Airways | CLICK AIR | Kyrgyzstan | |
| | CLZ | Cloud 9 Air Charters | CLOUDLINE | South Africa | |
| | CLD | Clowes Estates Limited | CLOWES | United Kingdom | |
| | SDJ | Club 328 | SPACEJET | United Kingdom | |
| 6P | ISG | Club Air | CLUBAIR | Italy | |
| BX | CST | Coast Air | COAST CENTER | Norway | |
| DQ | | Coastal Air | U.S. Virgin Islands | United States | |
| | TCL | Coastal Air Transport | TRANS COASTAL | United States | Escape Aviation |
| | CNG | Coastal Airways | SID-AIR | United States | |
| | CSV | Coastal Travels | COASTAL TRAVEL | Tanzania | |
| | CHL | Cohlmia Aviation | COHLMIA | United States | |
| | OLR | Colaéreos | COLAEREOS | Ecuador | |
| | CLE | Colemill Enterprises | COLEMILL | United States | |
| 9L | CJC | Colgan Air | COLGAN | United States | |
| | CAE | Colibri Aviation | HUMMINGBIRD | Canada | |
| YD | CAT | Cologne Air Transport GmbH | | Germany | defunct since 1996 |
| | CCX | Colt International | | United States | |
| | WCO | Columbia Helicopters | COLUMBIA HELI | United States | |
| | KLR | Columbus Air Transport | KAY-LER | United States | |
| | GHP | Colvin Aviation | GRASSHOPPER EX | United States | |
| OH | COM | Comair | COMAIR | United States | |
| MN | CAW | Comair | COMMERCIAL | South Africa | |
| | GCM | Comair Flight Services | GLOBECOM | South Africa | |
| | CDE | Comed Group | COMEX | United Kingdom | |
| | CVV | Comeravia | COMERAVIA | Venezuela | |
| | CRS | Comercial Aérea | COMERCIAL AEREA | Mexico | |
| | CMG | Comet Airlines | SUNSPY | Nigeria | |
| | FYN | Comfort Air | FLYNN | Germany | |
| | CMJ | Comfort Jet Services | COMFORT JET | Togo | |
| | CLA | Comlux Aviation | COMLUX | Switzerland | |
| | KAZ | Comlux Kazakhstan | KAZLUX | Kazakhstan | |
| | MLM | Comlux Malta | LUXMALTA | Malta | |
| | CXB | Comlux Aruba | STARLUX | Aruba | |
| | CMH | Commair Aviation | COMMODORE | United Kingdom | |
| | CTM | Commandement Du Transport Aerien Militaire Francais | COTAM | France | |
| | CML | Commander Air Charter | COMMANDAIR | Canada | |
| | CRM | Commander Mexicana | COMMANDERMEX | Mexico | |
| | CME | Commerce Bank | COMMERCE BANK | United States | (Kansas City) Allocated in 2014 |
| | CMS | Commercial Aviation | ACCESS | Canada | |
| | GAR | Commodore Aviation | | Australia | |
| | CJS | Commonwealth Jet Service | COMMONWEALTH | United States | |
| C5 | UCA | CommutAir | COMMUTAIR | United States | |
| KR | CWK | Comores Airlines | CONTICOM | Comoros | |
| | CGR | Compagnia Generale Ripreseaeree | COMPRIP | Italy | |
| | CMM | Compagnie Aérienne du Mali | CAMALI | Mali | |
| | CPM | Compagnie Mauritanienne Des Transports | | Mauritania | |
| | GIC | Compagnie de Bauxites de Guinee | CEBEGE | Guinea | |
| | AIF | Compañía Aérea de Valencia | | Spain | |
| | ATF | Compañía Aerotécnicas Fotográficas | AEROTECNICAS | Spain | |
| | LCT | Compañía De Actividades Y Servicios De Aviación | STELLAIR | Spain | |
| | EJV | Compania Ejecutiva | EJECUTIVA | Mexico | |
| | HSE | Compania Helicopteros Del Sureste | HELISURESTE | Spain | |
| | MDR | Compania Mexicana De Aeroplanos | AEROPLANOS | Mexico | |
| | HSS | Compañía Transportes Aéreos Del Sur | TAS HELICOPTEROS | Spain | |
| | TAV | Compañía de Servicios Aéreos Tavisa | TAVISA | Spain | |
| | CYF | Company Flight | COMPANY FLIGHT | Denmark | |
| CP | CPZ | Compass Airlines | COMPASS ROSE | United States | |
| | CPS | Compass International Airways | COMPASS | United Kingdom | |
| | XCO | Compuflight Operations Service | | United States | |
| | XCS | Compuserve Incorporated | | United States | |
| | CRC | Conair Aviation | CONAIR-CANADA | Canada | |
| | COD | Concordavia | CONCORDAVIA | Ukraine | |
| | CNR | Condor Aero Services | CONAERO | United States | |
| | CIB | Condor | CONDOR BERLIN | Germany | |
| DE | CFG | Condor Flugdienst | CONDOR | Germany | |
| | COF | Confort Air | CONFORT | Canada | |
| | CAK | Congo Air | | Bahamas | |
| | CGA | Congressional Air | CONGRESSIONAL | United States | |
| | ROY | Conifair Aviation | | Canada | |
| | CCT | Connect Air | CONNECT | Canada | Allocated in 2014 |
| | BSN | Connectair Charters | BASTION | Canada | |
| | CAC | Conquest Airlines | CONQUEST AIR | United States | |
| | CXO | Conroe Aviation Services | CONROE AIR | United States | |
| | VCH | Consorcio Helitec | CONSORCIO HELITEC | Venezuela | |
| | UZA | Constanta Airline | CONSTANTA | Ukraine | |
| | KIS | Contactair | CONTACTAIR | Germany | |
| | XCL | Contel ASC | | United States | |
| CO | COA | Continental Airlines | CONTINENTAL | United States | ICAO Code and callsign withdrawn, merged with United Airlines |
| | CNW | Continental Airways | | Moldovoa | 2014 |
| CO | | Continental Express | JETLINK | United States | |
| CS | CMI | Continental Micronesia | AIR MIKE | United States | |
| | CON | Continental Oil | CONOCO | United States | |
| CS | CS | Cambrian Airways | Cambrian | United Kingdom | defunct 1974 |
| V0 | VCV | Conviasa | CONVIASA | Venezuela | |
| | CKA | Cook Inlet Aviation | COOK-AIR | United States | |
| | SVY | Cooper Aerial Surveys | SURVEYOR | United Kingdom | |
| CM | CMP | Copa Airlines | COPA | Panama | |
| | CAT | Copenhagen Air Taxi | AIRCAT | Denmark | |
| | COP | Copper State Air Service | COPPER STATE | United States | |
| | AAQ | Copterline | COPTERLINE | Finland | Former name: Copter Action; former callsign: COPTER ACTION |
| CQ | CCW | Central Charter | CENTRAL CHARTER | Czech Republic | |
| XC | CAI | Corendon Airlines | CORENDON | Turkey | Turistik Hava Tasimacilik |
| CD | CND | Corendon Dutch Airlines | DUTCH CORENDON | Netherlands | |
| XR | CXI | Corendon Airlines Europe | CORENDON EUROPE | Malta | Touristic Aviation |
| | CRA | Coronado Aerolíneas | CORAL | Colombia | |
| | CPB | Corpac Canada | PENTA | Canada | |
| | CNC | Corporación Aéreo Cencor | CENCOR | Mexico | |
| | CPG | Corporacion Aeroangeles | CORPORANG | Mexico | |
| | CGY | Corporacion Paraguaya De Aeronautica | | Paraguay | |
| | CPT | Corporate Air | AIR SPUR | United States | |
| | CPR | Corporate Air | CORPAIR | United States | |
| | CPO | Corporate Aircraft Company | MOKAN | United States | |
| | COO | Corporate Airlink | CORPORATE | Canada | |
| | CKE | Corporate Aviation Services | CHECKMATE | United States | |
| | VHT | Corporate Flight International | VEGAS HEAT | United States | |
| LF | VTE | Contour Airlines | VOLUNTEER | United States | |
| | CJI | Corporate Jets | SEA JET | United States | |
| SS | CRL | Corsairfly | CORSAIR | France | |
| XK | CCM | Corse Méditerranée | CORSICA | France | Name changed to Air Corsica |
| F5 | COZ | Cosmic Air | COSMIC AIR | Nepal | |
| | COT | Costa Airlines | COAIR | Venezuela | defunct |
| GW | CRG | Costa Rica Green Airways | | Costa Rica | |
| | CHI | Cougar Helicopters | COUGAR | Canada | |
| | MGB | Coulson Flying Service | MOCKINGBIRD | United Kingdom | |
| | NSW | Country Connection Airlines | | Australia | |
| | CIK | Country International Airlines | COUNTRY AIR | Kyrgyzstan | Defunct |
| | CSD | Courier Services | DELIVERY | United States | |
| | CUT | Court Helicopters | COURT AIR | South Africa | |
| | OU | Court Line | COURTLINE | United Kingdom | defunct |
| | CVL | Coval Air | COVAL | Canada | |
| | COW | COWI | COWI | Denmark | |
| 7C | COY | Coyne Aviation | COYNE AIR | United Kingdom | |
| | CFD | Cranfield University | AERONAUT | United Kingdom | |
| | CRE | Cree Airways | CREE AIR | Canada | |
| | ELM | Crelam | CRELAM | Mexico | |
| | CAN | Crest Aviation | CREST | United Kingdom | |
| | KRM | Crimea Universal Avia | TRANS UNIVERSAL | Ukraine | |
| OU | CTN | Croatia Airlines | CROATIA | Croatia | |
| | HRZ | Croatian Air Force | CROATIAN AIRFORCE | Croatia | |
| | CRX | Cross Aviation | CROSSAIR | United Kingdom | |
| QE | ECC | Crossair Europe | Cigogne | Switzerland | |
| | CWX | Crow Executive Air | CROW EXPRESS | United States | |
| | CKR | Crown Air Systems | CROWN AIR | United States | |
| | CRO | Crown Airways | CROWN AIRWAYS | United States | |
| | CRW | Crownair | REGAL | Canada | |
| | VCR | Cruiser Linhas Aéreas | VOE CRUISER | Brazil | |
| | CTY | Cryderman Air Service | CENTURY | United States | |
| | CYT | Crystal Shamrock Airlines | CRYSTAL-AIR | United States | |
| | IRO | CSA Air | IRON AIR | United States | |
| CU | CUB | Cubana de Aviación | CUBANA | Cuba | |
| | CTF | Cutter Aviation | CUTTER FLIGHT | United States | |
| | CBL | Cumberland Airways (Nicholson Air Service) | CUMBERLAND | United States | |
| | CTT | Custom Air Transport | CATT | United States | |
| | RGN | Cygnus Air | CYGNUS AIR | Spain | |
| | CYC | Cyprair Tours | CYPRAIR | Cyprus | |
| | CYS | Cypress Airlines | SKYBIRD | Canada | |
| CY | CYP | Cyprus Airways | CYPRUS | Cyprus | |
| YK | KYV | Cyprus Turkish Airlines | AIRKIBRIS | Turkey | Ceased operations 2010 |
| | CEF | Czech Air Force | CZECH AIR FORCE | Czech Republic | |
| | AHD | Czech Air Handling | AIRHANDLING | Czech Republic | |
| OK | CSA | Czech Airlines | CSA-LINES | Czech Republic | |
| | CIE | Czech Government Flying Service | CZECH REPUBLIC | Czech Republic | |
| 8L | CGP | Cargo Plus Aviation | | United Arab Emirates | |
| | HNL | CHC Helicopters Netherlands | MAPLELEAF | Netherlands | |
| 5Z | KEM | CemAir | CEMAIR | South Africa | |
| | JLH | Centro de Servicio Aeronautico | CESA | Mexico | |
| | FCB | Cobalt | NEW AGE | Cyprus | |
| | CVK | CAVOK Airlines | CARGO LINE | Ukraine | |
| XG | CLI | Clickair | CLICKJET | Spain | Merge into Vueling |
| PN | CHB | West Air (China) | WEST CHINA | China | |
| | CRN | Carson Air Ltd | CARSON | Canada | Air ambulance operator |
| | DJT | Dreamjet | DREAMJET | France | 2014 |
| | DPJ | Delta Private Jets | JET CARD | United States | Changed from ELJ/ELITE JET in 2014 |
| | DJR | Desert Jet | DESERT FLIGHT | United States | |
| | DLA | Air Dolomiti | DOLOMITI | Italy | |
| | DLC | Dehong South Asian General Aviation | SOARCOPTER | China | Was Ruili Jingcheng Helicopters |
| DL | DLH | Deutsche Luft Hansa | DEUTSCHE LUFT HANSA | Germany | Became Lufthansa |
| | DNS | Dniproaviaservis Company | | Ukraine | |
| | DRF | Dream Flyers Training Center | | Spain | |
| | DMF | DMCFLY | DEMLY | Mexico | |
| | NAU | Danaus Lineas Aereas | DANAUS | Mexico | |
| | GDF | DF Aviation | | Ukraine | |
| | DDA | D & D Aviation | DUSTY | United States | |
| | DNK | D&K Aviation | DIRECT JET | United States | |
| V5 | VPA | DanubeWings | VIP TAXI | Slovakia | Former names VIP Air and VIP Wings |
| | DHE | DAP Helicopteros | HELIDAP | Chile | |
| | VLF | DFS UK Limited | VOLANTE | United Kingdom | |
| WD | DSR | DAS Air Cargo | DAIRAIR | Uganda | |
| | RKC | DAS Airlines | DAS CONGO | Democratic Republic of the Congo | |
| DX | DTR | DAT Danish Air Transport | DANISH | Denmark | |
| | ENT | DAT Enterprise Limited | DATENT | United Kingdom | defunct |
| | BDN | DERA Boscombe Down | GAUNTLET | United Kingdom | |
| | DSN | DESNA | DESNA | Ukraine | |
| | DET | DETA Air | SAMAL | Kazakhstan | |
| | DGO | DGO Jet | DGO JET | Mexico | |
| | DAE | DHL Aero Expreso | YELLOW | Panama | |
| D0 | DHK | DHL Air Limited | WORLD EXPRESS | United Kingdom | DHL Air UK |
| | DHV | DHL Aviation | WORLDSTAR | South Africa | |
| ES | DHX | DHL International | DILMUN | Bahrain | |
| L3 | JOS | DHL de Guatemala | | Guatemala | |
| | RSK | DSWA | REDSKIN | United States | |
| D3 | DAO | Daallo Airlines | DALO AIRLINES | Djibouti | |
| N2 | DAG | Dagestan Airlines | DAGAL | Russia | |
| | DHA | Dahla Airlines | | Democratic Republic of Congo | |
| CA | CCD | Dalian Airlines | XIANGJIAN | China | |
| | DCS | DC Aviation | TWIN STAR | Germany | |
| | DCX | Daimler-Chrysler | DAIMLER | United States | |
| | DKA | Daka | | Kazakhstan | |
| | DLR | Dala Air Services | DALA AIR | Nigeria | |
| H8 | KHB | Dalavia | DALAVIA | Russia | |
| | DXP | Dallas Express Airlines | DALLAS EXPRESS | United States | |
| | DAS | Damascene Airways | AIRDAM | Syrian Arab Republic | |
| | DSA | Danbury Airways | DANBURY AIRWAYS | United States | |
| | DOP | Dancopter | DANCOPTER | Denmark | |
| | DAF | Danish Air Force | DANISH AIRFORCE | Denmark | |
| DD | DDL | Danish Air Lines | | Denmark | defunct |
| | DAR | Danish Army | DANISH ARMY | Denmark | |
| | DNY | Danish Navy | DANISH NAVY | Denmark | |
| | DNU | Danu Oro Transportas | DANU | Lithuania | |
| | DRT | Darta | DARTA | France | |
| 0D | DWT | Darwin Airline | DARWIN | Switzerland | |
| | DSQ | Dasab Airlines | DASAB AIR | Uganda | |
| | DSH | Dash Air Charter | DASH CHARTER | United States | |
| | GOB | Dash Aviation | PILGRIM | United Kingdom | |
| | DGX | Dasnair | DASNA | Switzerland | |
| | DAB | Dassault Aviation | | France | |
| | CVF | Dassault Falcon Jet Corporation | CLOVERLEAF | United States | |
| | DSO | Dassault Falcon Service | DASSAULT | France | |
| | DTN | Data International | DATA AIR | Sudan | |
| | XDT | Date Transformation Corp | | United States | |
| D5 | DAU | Dauair | DAUAIR | Germany | |
| | DCO | David Crawshaw Consultants Limited | | United Kingdom | |
| | DWN | Dawn Air | DAWN AIR | United States | |
| | DJS | DayJet | DAYJET | United States | |
| | DAY | Daya Aviation | DAYA | Sri Lanka | |
| | DHC | De Havilland | DEHAVILLAND | Canada | |
| | IAY | Deadalos Flugtbetriebs | IASON | Austria | |
| | DAA | Decatur Aviation | DECUR | United States | |
| | DKN | Deccan Charters | DECCAN | India | |
| | JDC | Deere and Company | JOHN DEERE | United States | |
| | DWR | Delaware Skyways | DELAWARE | United States | |
| | DEA | Delta Aerotaxi | JET SERVICE | Italy | |
| | SNO | Delta Air Charter | SNOWBALL | Canada | |
| | ELJ | Delta Private Jets | ELITE JET | United States | Changed to DPJ/JET CARD in 2014 |
| DL | DAL | Delta Air Lines | DELTA | United States | |
| | KMB | Delta Engineering Aviation | KEMBLEJET | United Kingdom | |
| | DLI | Delta Express International | DELTA EXPRESS | Ukraine | |
| | DSU | Delta State University | DELTA STATE | United States | |
| J7 | DNM | Denim Air | DENIM | Netherlands | Defunct |
| | FEC | Denver Express | FALCON EXPRESS | United States | |
| | DJT | Denver Jet | DENVER JET | United States | |
| | FGC | Departament d'Agricultura de la Generalitat de Catalunya | FORESTALS | Spain | |
| | DRY | Deraya Air Taxi | DERAYA | Indonesia | |
| | DRX | Des R Cargo Express | | Mauritania | |
| | MIZ | Desarrollo Milaz | MILAZ | Mexico | |
| | DTY | Destiny Air Services | DESTINY | Sierra Leone | |
| 2A | | Deutsche Bahn | | Germany | |
| 1I | AMB | Deutsche Rettungsflugwacht | CIVIL AIR AMBULANCE | Germany | |
| | LFO | Deutsches Zentrum fur Luft-und Raumfahrt EV | LUFO | Germany | |
| | DIS | Di Air | DI AIR | Serbia | |
| | SPK | Diamond Aviation | SPARKLE | United States | |
| | DRB | Didier Rousset Buy | DIDIER | Chile | |
| | DGT | Digital Equipment Corporation | DIGITAL | United States | |
| | DIP | Diplomatic Freight Services | DIPFREIGHT | United Kingdom | |
| | ENA | Dirección General de Aviación Civil y Telecomunicasciones | ENA | Spain | |
| | DIA | Direct Air | BLUE SKY | United States | |
| | XAP | Direct Air trading as Midway Connection | MID-TOWN | United States | |
| | DCT | Direct Flight | | United Kingdom | |
| | SXP | Direct Fly | EXPRESS SKY | Poland | defunct |
| AW | DIR | Dirgantara Air Service | DIRGANTARA | Indonesia | |
| | DCV | Discover Air | DISCOVER | United States | |
| DH | DVA | Discovery Airways | DISCOVERY AIRWAYS | United States | |
| | XDS | Dispatch Services | | United States | |
| | DIX | Dix Aviation | DIX FLIGHT | Germany | |
| | DEE | Dixie Airways | TACAIR | United States | |
| Z6 | UDN | Dniproavia | DNIEPRO | Ukraine | |
| | FDN | Dolphin Air | FLYING DOLPHIN | United Arab Emirates | |
| | IXX | Dolphin Express Airlines | ISLAND EXPRESS | United States | |
| | DPL | Dome Petroleum | DOME | Canada | |
| YU | ADM | Dominair | DOMINAIR | Dominican Republic | defunct; former IATA code: SS; former name: Aerolíneas Dominicanas, ICAO code no longer allocated |
| | MYO | Dominguez Toledo (Grupo Mayoral) | MAYORAL | Spain | |
| DO | DOA | Dominicana de Aviación | DOMINICANA | Dominican Republic | defunct |
| E3 | DMO | Domodedovo Airlines | DOMODEDOVO | Russia | defunct |
| | DVB | Don Avia | DONSEBAI | Kazakhstan | |
| | DON | Donair Flying Club | DONAIR | United Kingdom | |
| D9 | DNV | Donavia | DONAVIA | Russia | formerly Aeroflot-Don |
| 5D | UDC | DonbassAero | DONBASS AERO | Ukraine | |
| DZ | EPA | Donghai Airlines | DONGHAI AIR | China | |
| | DAD | Dorado Air | DORADO AIR | Dominican Republic | |
| | DOR | Dornier | DORNIER | Germany | |
| | DAV | Dornier Aviation Nigeria | DANA AIR | Nigeria | |
| | DOM | Dos Mundos | DOS MUNDOS | Dominican Republic | |
| | DCA | Dreamcatcher Airways | DREAM CATCHER | United Kingdom | |
| KB | DRK | Druk Air | ROYAL BHUTAN | Bhutan | |
| | DRE | Drummond Island Air | MICHIGAN | United States | |
| | DUB | Dubai Airwing | DUBAI | United Arab Emirates | |
| | DBK | Dubrovnik Air | SEAGULL | Croatia | |
| | DUK | Ducair | LION KING | Luxembourg | |
| | DBJ | Duchess of Brittany (Jersey) Limited | DUCHESS | United Kingdom | |
| | LPD | UK Royal/HRH Duke of York | LEOPARD | United Kingdom | |
| | DUN | Dun'Air | DUNAIR | Mauritania | |
| | PHD | Duncan Aviation | PANHANDLE | United States | |
| | VVF | Dunyaya Bakis Hava Tasimaciligi | WORLDFOCUS | Turkey | |
| | DUO | Duo Airways | FLY DUO | United Kingdom | |
| | DJE | Durango Jet | DURANGO JET | Mexico | |
| | DNL | Dutch Antilles Express | DUTCH ANTILLES | Netherlands Antilles | |
| | DCE | Dutch Caribbean Express | DUTCH CARIBBEAN | Netherlands Antilles | |
| | DBR | Dutchbird | DUTCHBIRD | Netherlands | ICAO code allocated to another company, call sign no longer allocated |
| | DBR | Dobrolet LLC | DOBROLET | Russia | Defunct, ICAO code still allocated (2017) |
| | DFS | Dwyer Aircraft Services | DWYAIR | United States | |
| | XDY | Dynair Services | | United States | |
| | DNR | Dynamair Aviation | DYNAMAIR | Canada | |
| | DYE | Dynamic Air | DYNAMIC | Netherlands | ICAO code and call sign no longer allocated |
| | DYA | Dynamic Airways | DYNAMIC AIR | United States | |
| DI | BAG | Dba | SPEEDWAY | Germany | Merged into Air Berlin |
| HO | DKH | Juneyao Air | AIR JUNEYAO | China |
| | EAV | Eagle Airlines Luftverkehrsges | MAYFLOWER | Austria | |
| | ABU | Eagle Aviation Services | | United States | |
| | ISL | Eastland Air Services (Flugfélag Austurlands) | EASTLAND | Iceland | 2022 |
| | EBF | Echo Airlines | | Bahamas | 2014 |
| MQ | ENY | Envoy Air | ENVOY | United States | 2014 |
| | ENK | Executive Airlink | SUNBIRD | United States | Allocated in 2014 |
| EL | ELB | Ellinair | ELLINAIR HELLAS | Greece | |
| | ELN | Eleron Aviation Company | ELERON | Ukraine | |
| | ECC | Eclair Aviation | ECLAIR | Czech Republic | |
| | ELU | Egyptian Leisure Airlines | EGYPTIAN LEISURE | Egypt | |
| 9E | EDV | Endeavor Air | ENDEAVOR | United States | |
| | MNU | Elite Airways | MAINER | United States | |
| | | Europe Jet | EUROPE JET | Turkey | |
| E1 | | Everbread | | United Kingdom | |
| | EHD | E H Darby Aviation | PLATINUM AIR | United States | |
| 1C | | Electronic Data Systems | | Switzerland | |
| 1Y | | Electronic Data Systems | | United States | |
| | EXW | Executive Airlines Services | ECHOLINE | Nigeria | |
| | EFS | EFAOS- Agencia De Viagens e Turismo | EFAOS | Angola | |
| | EFD | Eisele Flugdienst | EVER FLIGHT | Germany | |
| | FSD | EFS-Flugservice | FLUGSERVICE | Germany | |
| | EIS | EIS Aircraft | COOL | Germany | |
| | IAG | EPAG | EPAG | France | |
| | ESI | ESI Eliservizi Italiani | ELISERVIZI | Italy | |
| | EUY | EU Airways | EUROAIRWAYS | Ireland | |
| VE | EUJ | EUjet | UNION JET | Ireland | defunct |
| | ICR | Eagle Aero | ICARUS FLIGHTS | United States | |
| | FEI | Eagle Air | ARCTIC EAGLE | Iceland | |
| | | Eagle Air | | Indonesia | |
| | EGR | Eagle Air | EAGLE SIERRA | Sierra Leone | |
| | EFL | Eagle Air | FLYING EAGLE | Tanzania | defunct 2002 |
| H7 | EGU | Eagle Air | AFRICAN EAGLE | Uganda | |
| NZ | EAG | Eagle Airways | EAGLE | New Zealand | |
| | EGX | Eagle Air Company | THAI EAGLE | Thailand | |
| | GYP | Eagle Aviation | GYPSY | United Kingdom | |
| | EGN | Eagle Aviation France | FRENCH EAGLE | France | |
| | EES | Eagle Express | | Serbia | 2014 |
| 9A | EZX | Eagle Express Air Charter | EAGLEXPRESS | Malaysia | |
| | SEG | Eagle International | SEN-EAGLE | Senegal | |
| | EGJ | Eagle Jet Charter | EAGLE JET | United States | |
| | EMD | Eaglemed (Ballard Aviation) | EAGLEMED | United States | |
| | ERX | Earth Airlines Services | EARTH AIR | Nigeria | |
| S9 | HSA | East African Safari Air | DUMA | Kenya | |
| | EXZ | East African Safari Air Express | TWIGA | Kenya | |
| E3 | EMU | East Asia Airlines | EAST ASIA | Macao | |
| | ECT | East Coast Airways | EASTWAY | South Africa | |
| | ECJ | East Coast Jets | EASTCOAST JET | United States | |
| | EHA | East Hampton Aire | AIRE HAMPTON | United States | |
| | EKC | East Kansas City Aviation | BLUE GOOSE | United States | |
| | CTK | East Midlands Helicopters | COSTOCK | United Kingdom | |
| | DXH | East Star Airlines | EAST STAR | China | |
| | EWA | East-West Airlines | EASTWEST | Australia | defunct |
| ZE | ESR | Eastar Jet | EASTAR | South Korea | |
| | EAZ | Eastern Air | EASAIR | Zambia | |
| | EAX | Eastern Air Executive | EASTEX | United Kingdom | |
| EA | EAL | Eastern Air Lines | EASTERN | United States | defunct |
| | EAL | Eastern Air Lines | EASTERN | United States | 2015 |
| T3 | EZE | Eastern Airways | EASTFLIGHT | United Kingdom | |
| QF | EAQ | Eastern Australia Airlines | EASTERN | Australia | IATA dupe with parent QANTAS. Also uses 2 letter ICAO EA. |
| | ECI | Eastern Carolina Aviation | EASTERN CAROLINA | United States | |
| | GNS | Eastern Executive Air Charter | GENESIS | United Kingdom | |
| | LIS | Eastern Express | LARISA | Kazakhstan | |
| | EME | Eastern Metro Express | EMAIR | United States | |
| | EPB | Eastern Pacific Aviation | EAST PAC | Canada | |
| | ESJ | Eastern SkyJets | EASTERN SKYJETS | United Arab Emirates | |
| DK | ELA | Eastland Air | | Australia | |
| W9 | SGR | Eastwind Airlines | STINGER | United States | defunct |
| | FYE | Easy Link Aviation Services | FLYME | Nigeria | |
| EC | EJU | easyJet Europe | ALPINE | Austria | |
| DS | EZS | easyJet Switzerland | TOPSWISS | Switzerland | |
| U2 | EZY | easyJet UK | EASY | United Kingdom | |
| | CMN | Eckles Aircraft | CIMMARON AIRE | United States | |
| | EJT | Eclipse Aviation | ECLIPSE JET | United States | |
| | ECQ | Eco Air | SKYBRIDGE | Nigeria | |
| | DEI | Ecoair | | Algeria | |
| | NAK | École Nationale de l'Aviation Civile | ENAC SCHOOL | France | Formerly SFA prior to SEFA ATO being absorbed by the École Nationale de l'Aviation Civile. |
| | ECX | Ecomex Air Cargo | AIR ECOMEX | Angola | |
| | ECD | Ecotour | ECOTOUR | Mexico | |
| | XCC | Ecoturistica de Xcalak | XCALAK | Mexico | |
| | ECV | Ecuatoguineana De Aviación (EGA) | EQUATOGUINEA | Equatorial Guinea | |
| | EQC | Ecuatorial Cargo | ECUA-CARGO | Equatorial Guinea | |
| | ECU | Ecuavia | ECUAVIA | Ecuador | |
| WK | EDW | Edelweiss Air | EDELWEISS | Switzerland | |
| | SLO | Edgartown Air | SLOW | United States | |
| | EDC | Air Charter Scotland | SALTIRE | United Kingdom | Previously: Edinburgh Air Charter |
| | EDJ | Edwards Jet Center of Montana | EDWARDS | United States | |
| | EIJ | Efata Papua Airlines | EFATA | Indonesia | |
| | EUW | EFS European Flight Service | EUROWEST | Sweden | |
| MS | MSR | Egyptair | EGYPTAIR | Egypt | |
| | MSX | Egyptair Cargo | EGYPTAIR CARGO | Egypt | |
| | EGY | Egyptian Air Force | | Egypt | |
| | EJX | Egyptian Aviation | | Egypt | |
| | EMA | Egyptian Aviation Company | | Egypt | |
| | EIX | Ei Air Exports | AIR EXPORTS | Ireland | |
| | EIR | Eirjet | EIRJET | Ireland | |
| LY | ELY | El Al Israel Airlines | ELAL | Israel | |
| | CMX | El Caminante Taxi Aéreo | EL CAMINANTE | Mexico | |
| | GLQ | El Quilada International Aviation | QUILADA | Sudan | |
| | ELS | El Sal Air | EL SAL | El Salvador | |
| | ESC | El Sol De América | SOLAMERICA | Venezuela | |
| UZ | BRQ | El-Buraq Air Transport | BURAQAIR | Libya | |
| | ELX | Elan Express | ELAN | United States | |
| | LBR | Elbe Air Transport | MOTION | Germany | |
| | NLK | Elbrus-Avia Air Enterprise | ELAVIA | Russia | |
| | DND | Eldinder Aviation | DINDER | Sudan | |
| | PDV | Elicar | ELICAR | Italy | |
| | EDO | Elidolomiti | ELIDOLOMITI | Italy | |
| | ELB | Elieuro | ELILOBARDIA | Italy | No longer used |
| | EFG | Elifriulia | ELIFRIULIA | Italy | |
| | ELH | Elilario Italia | LARIO | Italy | |
| | EOA | Elilombarda | LOMBARDA | Italy | |
| | MEE | Elimediterranea | ELIMEDITERRANEA | Italy | |
| | VUL | Elios | ELIOS | Italy | |
| | IEP | Elipiu' | ELIPIU | Italy | |
| | RSA | Elisra Airlines | ESRA | Sudan | |
| | EAI | Elite Air | ELAIR | Togo | |
| | EJD | Elite Jets | ELITE DUBAI | United Arab Emirates | |
| | FGS | Elitellina | ELITELLINA | Italy | |
| | ELT | Elliott Aviation | ELLIOT | United States | |
| | MGG | Elmagal Aviation Services | ELMAGAL | Sudan | |
| | ELR | Elrom Aviation and Investments | | Israel | |
| | EAM | Embassy Airlines | EMBASSY AIR | Nigeria | |
| | EFT | Embassy Freight Company | EMBASSY FREIGHT | United States | |
| | EMB | Empresa Brasileira De Aeronáutica | EMBRAER | Brazil | |
| | XSL | Embry-Riddle Aeronautical University | SATSLAB | United States | Sesatlab Proof-of-Concept Flight |
| EA | EAI | Emerald Airlines | GEMSTONE | Ireland | |
| | JEM | Emerald Airways | GEMSTONE | United Kingdom | |
| | EWW | Emery Worldwide Airlines | EMERY | United States | |
| | EMT | Emetebe | EMETEBE | Ecuador | |
| EK | UAE | Emirates Airlines | EMIRATES | United Arab Emirates | |
| | SBC | Emoyeni Air Charter | SABIAN AIR | South Africa | Mount Air |
| | EMP | Empire Air Service | EMPIRE | United States | |
| EM | CFS | Empire Airlines | EMPIRE AIR | United States | |
| | MPR | Empire Aviation Services | | Nigeria | |
| | ETP | Empire Test Pilots' School | TESTER | United Kingdom | |
| | AUO | Empresa (Aero Uruguay), S.A. | UNIFORM OSCAR | Uruguay | |
| | PRG | Empresa Aero-Servicios Parrague | ASPAR | Chile | |
| | CRN | Aero Caribbean | AEROCARIBBEAN | Cuba | Merged into Cubana de Aviación in 2015 |
| | VNA | Empresa Aviación Interamericana | EBBA | Uruguay | |
| EU | EEA | Empresa Ecuatoriana De Aviación | ECUATORIANA | Ecuador | |
| | CNI | Empresa Nacional De Servicios Aéreos | SERAER | Cuba | |
| | VNE | Empresa Venezolana | VENEZOLANA | Venezuela | |
| | GTV | Empresa de Aviación Aerogaviota | GAVIOTA | Cuba | |
| | XLT | Empressa Brasileira de Infra-Estrutura Aeroportuaria-Infraero | INFRAERO | Brazil | |
| | ENC | Endecots | ENDECOTS | Ecuador | |
| | ENI | Enimex | ENIMEX | Estonia | |
| G8 | ENK | Enkor JSC | ENKOR | Russia | |
| | EGV | Enrique Gleisner Vivanco | GLEISNER | Chile | |
| | ESE | Ensenada Vuelos Especiales | ENSENADA ESPECIAL | Mexico | |
| OF | ENT | Enter Air | ENTER | Poland | |
| | ENS | Entergy Services | ENTERGY SHUTTLE | United States | |
| | EWS | Enterprise World Airways | WORLD ENTERPRISE | Democratic Republic of the Congo | |
| E0 | ESS | Eos Airlines | NEW DAWN | United States | |
| | EKA | Equaflight Service | EQUAFLIGHT | Republic of the Congo | |
| | EQZ | Equatair Air Services (Zambia) | ZAMBIA CARGO | Zambia | |
| | EQT | Equatorial Airlines | | Equatorial Guinea | |
| | ERH | Era Helicopters | ERAH | United States | |
| | IRY | Eram Air | ERAM AIR | Iran | |
| | ERF | Erfoto | ERFOTO | Portugal | |
| | ERE | Erie Airways | AIR ERIE | United States | |
| B8 | ERT | Eritrean Airlines | ERITREAN | Eritrea | |
| | EAD | Escola De Aviacao Aerocondor | AERO-ESCOLA | Portugal | |
| | CTV | Escuela De Pilotos Are Aviación | ARE AVIACION | Spain | |
| | EPC | Espace Aviation Services | ESPACE | Democratic Republic of the Congo | |
| | ERC | Esso Resources Canada | ESSO | Canada | |
| E7 | ESF | Estafeta Carga Aérea | | Mexico | |
| | EEF | Estonian Air Force | ESTONIAN AIR FORCE | Estonia | |
| OV | ELL | Estonian Air | ESTONIAN | Estonia | |
| | ETA | Estrellas Del Aire | ESTRELLAS | Mexico | |
| ET | ETH | Ethiopian Airlines | ETHIOPIAN | Ethiopia | |
| | MJM | Eti 2000 | ELCO ETI | Italy | |
| EY | ETD | Etihad Airways | ETIHAD | United Arab Emirates | |
| | ETM | Etram Air Wing | ETRAM | Angola | |
| | EVN | Euraviation | EURAVIATION | Italy | |
| | ECN | Euro Continental AIE | EURO CONTINENTAL | Spain | |
| RZ | | Euro Exec Express | | Sweden | |
| | ESN | Euro Sun | EURO SUN | Turkey | |
| | EAK | Euro-Asia Air | EAKAZ | Kazakhstan | |
| | KZE | Euro-Asia Air International | KAZEUR | Kazakhstan | |
| MM | MMZ | EuroAtlantic Airways | EUROATLANTIC | Portugal | |
| | GOJ | EuroJet Aviation | GOJET | United Kingdom | |
| | EUP | Pan Europeenne Air Service | SAVOY | France | |
| | EUU | Euroamerican Air | EUROAMERICAN | Uruguay | |
| | ECY | Euroceltic Airways | ECHELON | United Kingdom | |
| | EUC | Eurocontrol | | Belgium | |
| | ECF | Eurocopter | EUROCOPTER | France | |
| UI | ECA | Eurocypria Airlines | EUROCYPRIA | Cyprus | |
| GJ | EEZ | Eurofly | E-FLY | Italy | |
| | EEU | Eurofly Service | EUROFLY | Italy | |
| | EUG | Euroguineana de Aviación | EUROGUINEA | Equatorial Guinea | |
| | ERJ | Eurojet Italia | JET ITALIA | Italy | |
| | JLN | Eurojet Limited | JET LINE | Malta | |
| | RDP | Eurojet Romania | JET-ARROW | Romania | |
| | EJS | Eurojet Servis | EEJAY SERVICE | Czech Republic | |
| K2 | ELO | Eurolot | EUROLOT | Poland | |
| 3W | EMX | Euromanx Airways | EUROMANX | Austria | |
| | GED | Europe Air Lines | LANGUEDOC | France | |
| 5O | FPO | Europe Airpost | FRENCH POST | France | |
| | EUT | European 2000 Airlines | FIESTA | Malta | |
| | EAG | European Aeronautical Group UK | | United Kingdom | defunct |
| EA | EAL | European Air Express | STAR WING | Germany | |
| QY | BCS | European Air Transport | POSTMAN | Belgium | |
| E7 | EAF | European Aviation Air Charter | EUROCHARTER | United Kingdom | |
| | EBJ | European Business Jets | | United Kingdom | |
| | ECB | European Coastal Airlines | COASTAL CLIPPER | Croatia | |
| | ETV | European Executive | EURO EXEC | United Kingdom | |
| | EXC | European Executive Express | ECHO EXPRESS | Sweden | |
| | EBG | Eurosense | EUROSENSE | Bulgaria | |
| | ESX | Euroskylink | CATFISH | United Kingdom | |
| EW | EWG | Eurowings | EUROWINGS | Germany | |
| 4Y | OCN | Eurowings Discover | OCEAN | Germany | |
| E6 | EWL | Eurowings Europe | Black Pearl | Malta | |
| BR | EVA | EVA Air | EVA | Taiwan | |
| | EVE | Evelop Airlines | EVELOP | Spain | |
| | EVK | Everett Aviation | EVERETT | Kenya | |
| | EVT | Everett Limited | | Tanzania | |
| EZ | EIA | Evergreen International Airlines | EVERGREEN | United States | |
| | VTS | Everts Air Alaska/Everts Air Cargo | EVERTS | United States | |
| | EVL | Evolem Aviation | EVOLEM | France | |
| ZD | EWR | Ewa Air | MAYOTTE AIR | France | |
| | EMN | Examiner Training Agency | AGENCY | United Kingdom | |
| JN | XLA | Excel Airways | EXPO | United Kingdom | |
| | XEL | Excel Charter | HELI EXCEL | United Kingdom | |
| | GZA | Excellent Air | EXCELLENT AIR | Germany | |
| MB | EXA | Execair Aviation | CANADIAN EXECAIRE | Canada | |
| | VCN | Execujet Charter | AVCON | Switzerland | |
| | EJO | Execujet Middle East | MIDJET | United Arab Emirates | |
| | VMP | Execujet Scandinavia | VAMPIRE | Denmark | |
| | LFL | Executive Air | LIFE FLIGHT | Zimbabwe | |
| | EAC | Executive Air Charter | EXECAIR | United States | |
| | XAF | Executive Air Fleet | | United States | |
| | ECS | Executive Aircraft Charter and Charter Services | ECHO | Ireland | |
| | XAH | Executive Aircraft Services | | United Kingdom | |
| OW | EXK | Executive Airlines | EXECUTIVE EAGLE | United States | American Eagle |
| | EXU | Executive Airlines | SACAIR | Spain | |
| | JTR | Executive Aviation Services | JESTER | United Kingdom | |
| | EXE | Executive Flight | EXEC | United States | |
| | TRI | Executive Flight Operations Ontario Government | TRILLIUM | Canada | |
| | EXJ | Executive Jet Charter | | United Kingdom | |
| | EJM | Executive Jet Management | JET SPEED | United States | |
| | TEA | Executive Turbine Aviation | TRAVELMAX | South Africa | |
| | EXF | Eximflight | EXIMFLIGHT | Mexico | |
| | EXN | Exin | EXIN | Poland | |
| | EXR | Expertos En Carga | EXPERTOS ENCARGA | Mexico | |
| | FXA | Express Air | EFFEX | United States | |
| | EIC | Express International Cargo | EXCARGO | São Tomé and Príncipe | |
| | XPL | Express Line Aircompany | EXPRESSLINE | United States | |
| | XNA | Express Net Airlines | EXPRESSNET | United States | |
| EO | LHN | Express One International | LONGHORN | United States | defunct |
| | XTO | Express Tours | EXPRESS TOURS | Canada | |
| EV | ASQ | ExpressJet | ACEY | United States | |
| | XSL | Excel-Aire Service | EXCELAIRE | United States | |
| | LTD | Executive Express Aviation/JA Air Charter | LIGHT SPEED | United States | |
| | XSR | Executive Flight Services | AIRSHARE | United States | |
| | EPR | Express Airways | EMPEROR | Slovenia | |
| | XRO | ExxAero | CRAMER | Netherlands | |
| | JTM | Exxavia Limited | SKYMAN | Ireland | |
| | EZJ | Ezjet GT | GUYANA JET | Guyana | |
| 8K | EVS | Exploits Valley Air Services | EVAS | Canada | |
| | FRX | Fort Aero | FORT AERO | Estonia | |
| | PBR | Fast Air | POLAR BEAR | Canada | |
| | SRE | Fly Jetstream Aviation | STREAMJET | South Africa | |
| | FTZ | Fastjet | GREY BIRD | Tanzania | |
| | FAP | F Air | FAIR SCHOOL | Czech Republic | |
| | FFL | ForeFlight | FOREFLIGHT | United States | 3rd party Privacy ICAO Address (PIA) callsign used to obscure true airplane registrations |
| | EYE | F.S. Air Service | SOCKEYE | United States | |
| | IFA | FAI Air Service | RED ANGEL | Germany | |
| | FLC | FINFO Flight Inspection Aircraft | FLIGHT CHECK | United States | |
| | FKI | FLM Aviation Mohrdieck | KIEL AIR | Germany | |
| | DCM | FLTPLAN (anonymized service) | DOT COM | United States | 3rd party Privacy ICAO Address (PIA) callsign used to obscure true airplane registrations |
| | FLW | FLowair Aviation | QUICKFLOW | France | |
| | FMG | FMG Verkehrsfliegerschule Flughafen Paderborn-Lippstadt | HUSKY | Germany | |
| | FRA | FR Aviation | RUSHTON | United Kingdom | |
| | FSB | FSB Flugservice & Development | SEABIRD | Germany | |
| | LEJ | FSH Luftfahrtunternehmen | LEIPZIG FAIR | Germany | |
| | FBA | Fab Air | FAB AIR | Kyrgyzstan | |
| | FCS | Facts Air | MEXFACTS | Mexico | |
| | FAV | Fair Aviation | FAIRAVIA | South Africa | |
| | FWD | Fair Wind Air Charter | FAIR WIND | United Arab Emirates | |
| | FLS | Fairlines | FAIRLINE | Netherlands | Defunct |
| | FFC | Fairoaks Flight Centre | FAIROAKS | United Kingdom | |
| | FWY | Fairways Corporation | FAIRWAYS | United States | |
| | FCN | Falcon Air | FALCON | Sweden | |
| | FAR | Falcon Air | FALCAIR | Slovenia | |
| | FAO | Falcon Air Express | PANTHER | United States | |
| | FAU | Falcon Airline | FALCON AIRLINE | Nigeria | |
| | FBU | French Bee | FRENCH BEE | France | |
| IH | | Falcon Aviation | | Sweden | |
| | FVS | Falcon Aviation Services | FALCON AVIATION | United Arab Emirates | |
| | FJC | Falcon Jet Centre | FALCONJET | United Kingdom | |
| | FAW | Falwell Aviation | FALWELL | United States | |
| FE | FEA | Far Eastern Air Transport | Far Eastern | Taiwan | |
| FD | | Royal Flying Doctor Service | FLYDOC | Australia | |
| | FDL | Farmingdale State University | FARMINGDALE STATE | United States | |
| | FAH | Farnair Hungary | BLUE STRIP | Hungary | |
| | FRN | Farnair Netherlands | FARNED | Netherlands | Defunct, ICAO code in use by another company |
| | FAT | ASL Airlines Switzerland | FARNER | Switzerland | Previously: Farnair Switzerland |
| | RAF | Farnas Aviation Services | FARNAS | Sudan | |
| | HBL | Faroecopter | HELIBLUE | Denmark | |
| F6 | RCK | FaroeJet | ROCKROSE | Faroe Islands | |
| | FRW | Farwest Airlines | FARWEST | United States | |
| F3 | FSW | Faso Airways | FASO | Burkina Faso | |
| | FHL | Fast Helicopters | FINDON | United Kingdom | |
| | FAY | Fayban Air Services | FAYBAN AIR | Nigeria | |
| | SKM | Fayetteville Flying Service and Scheduled Skyways System | SKYTEM | United States | |
| | FDR | Federal Air | FEDAIR | South Africa | |
| | FLL | Federal Airlines | FEDERAL AIRLINES | Sweden | |
| | DCN | Federal Armed Forces | DIPLOMATIC CLEARANCE | Germany | |
| | FRM | Federal Armored Service | FEDARM | United States | |
| | NHK | Federal Aviation Administration | NIGHTHAWK | United States | |
| FX | FDX | FedEx Express | FEDEX | United States | |
| | FNK | Feniks Airline | AURIKA | Kazakhstan | |
| | FER | Feria Aviación | FERIA | Spain | |
| N8 | HGK | Fika Salaama Airlines | SALAAMA | Uganda | |
| 4S | FNC | Finalair Congo | FINALAIR CONGO | Republic of the Congo | |
| | FAK | Financial Airxpress | FACTS | United States | |
| | FBF | Fine Airlines | FINE AIR | United States | |
| | FTR | Finist'air | FINISTAIR | France | |
| AY | FIN | Finnair | FINNAIR | Finland | |
| FC | WBA | Finncomm Airlines | WESTBIRD | Finland | |
| | FNF | Finnish Air Force | FINNFORCE | Finland | |
| | FIH | FinnHEMS | FINNHEMS | Finland | |
| FY | FFM | Firefly | FIREFLY | Malaysia | |
| 7F | FAB | First Air | FIRST AIR | Canada | |
| | JRF | First Air Transport | | Japan | |
| | FCC | First Cambodia Airlines | FIRST CAMBODIA | Cambodia | |
| | FCA | Fly-Coop Air Service | COOPAIR | Hungary | |
| | MBL | First City Air | FIRST CITY | United Kingdom | |
| | GGA | First Flying Squadron | JAWJA | United States | |
| | FIR | First Line Air | FIRSTLINE AIR | Sierra Leone | |
| | FTS | First Sabre | FIRST SABRE | Mexico | |
| 8F | FFR | Fischer Air | FISCHER | Czech Republic | |
| | FFP | Fischer Air Polska | FLYING FISH | Poland | |
| 8D | EXV | FitsAir | EXPOAVIA | Sri Lanka | |
| | FSX | Flagship Express Services | FLAG | United States | |
| F8 | FLE | Flair Airlines | FLAIR | Canada | |
| | WAF | Flamenco Airways | FLAMENCO | United States | |
| | FMR | Flamingo Air | FLAMINGO AIR | United States | |
| | FLN | Flamingo Air-Line | ILIAS | Kazakhstan | |
| | FSH | Flash Airlines | FLASH | Egypt | |
| | BWY | Fleet Requirements Air Direction Unit | BROADWAY | United Kingdom | |
| | FLR | Fleetair | FLEETAIR | South Africa | |
| | FXY | Flexair | FLEXY | Netherlands | Defunct |
| | FXT | Flexflight | | Denmark | |
| | TUD | Flight Alaska | TUNDRA | United States | |
| | FCK | FCS Flight Calibration Services | NAV CHECKER | Germany | |
| | VOR | Flight Calibration Services Ltd. | FLIGHT CAL | United Kingdom | |
| | FCV | Flight Centre Victoria | NAVAIR | Canada | |
| | FCP | Nelson Aviation College Ltd | FLIGHTCORP | New Zealand | Nelson Aviation College Archived 2017-06-07 at the Wayback Machine |
| | FDP | Flight Dispatch Services | | Poland | |
| | FLX | Flight Express, Inc. | FLIGHT EXPRESS | United States | |
| | CFI | Flight Inspection Center of the General Administration of Civil Aviation in China | CHINA JET | China | |
| | LTS | Flight Inspections and Systems | SPECAIR | Russia | |
| | IVJ | Flight International | INVADER JACK | United States | |
| | MIT | Flight Line | MATCO | United States | |
| | FOI | Flight Ops International | | United States | |
| | OPT | Flight Options | OPTIONS | United States | |
| | CLB | Flight Precision Limited | CALIBRATOR | United Kingdom | |
| | FSL | Flight Safety Limited | FLIGHTSAFETY | United Kingdom | |
| | FSU | Flight Support Sweden | | Sweden | |
| | CCK | Flight Trac | CABLE CHECK | United States | |
| | AYR | Flight Training Europe | CYGNET | Spain | |
| | FWQ | Flight West Airlines | UNITY | Australia | |
| | KLO | Flight-Ops International | KLONDIKE | Canada | |
| | CSK | Flightcraft | CASCADE | United States | |
| | FEX | Flightexec | FLIGHTEXEC | Canada | |
| B5 | FLT | Flightline | FLIGHTLINE | United Kingdom | defunct |
| | FTL | Flightline | FLIGHT-AVIA | Spain | |
| | FPS | Flightpass Limited | FLIGHTPASS | United Kingdom | |
| | FSR | Flightstar Corporation | FLIGHTSTAR | United States | |
| | KDZ | Flightworks | KUDZU | United States | Avior Technologies Operations |
| | FAZ | Flint Aviation Services | FLINT AIR | United States | |
| | KWX | Florida Aerocharter | KAY DUB | United States | Allocated in 2014 |
| | OJY | Florida Air | OHJAY | United States | |
| | FAS | Florida Air Cargo | FLORIDA CARGO | United States | Allocated in 2014 |
| PA | FCL | Florida Coastal Airlines | FLORIDA COASTAL | United States | |
| | FFS | Florida Department of Agriculture | FORESTRY | United States | |
| | FJS | Florida Jet Service | FLORIDAJET | United States | |
| RF | FWL | Florida West International Airways | FLO WEST | United States | merged into Atlas Air Worldwide Holdings; defunct as of 28 February 2017, IATA code now allocated to another user |
| | FFG | Flugdienst Fehlhaber | WITCHCRAFT | Germany | |
| | FLU | Flugschule Basel | YELLOW FLYER | Switzerland | |
| | EZB | Flugschule Eichenberger | EICHENBURGER | Switzerland | |
| | FWZ | Flugwerkzeuge Aviation Software | | Austria | |
| | VNX | Fly Advance | VANCE | United States | Allocated in 2014 |
| F2 | FLM | Fly Air | FLY WORLD | Turkey | |
| 8W | EDR | Fly All Ways | BIRDVIEW | Suriname | |
| G6 | ACY | Fly Arna | ARNA | Armenia | |
| | FCT | Fly CI Limited | DEALER | United Kingdom | |
| | FEE | Fly Europa Limited | FLY EURO | United Kingdom | |
| | FXL | Fly Excellent | FLY EXCELLENT | Sweden | |
| 9Y | FGE | Fly Georgia | GEORGIA WING | Georgia | |
| | NVJ | Fly International Airways | NOUVINTER | Tunisia | |
| OJ | FJM | Fly Jamaica Airways | GREENHEART | Jamaica | defunct |
| 9P | FJL | Fly Jinnah | Okaab | Pakistan | |
| | FIL | Fly Line | FLYLINE | Spain | |
| SH | FLY | Fly Me Sweden | FLYBIRD | Sweden | |
| FP | PVV | Fly Pro | Sunday | Moldova | |
| | FRB | Fly Rak | RAKWAY | United Arab Emirates | |
| 6P | IAD | Fly Wex | FLYWEX | Italy | |
| F6 | VAW | Fly2Sky | SOFIA JET | Bulgaria | |
| | FYA | Flyant | FLYANT | Spain | |
| D7 | XFA | FlyAsianXpress | FAX AIR | Malaysia | |
| F7 | BBO | Flybaboo | BABOO | Switzerland | |
| BE | BEE | Flybe | JERSEY | United Kingdom | Formerly Jersey European Airways |
| FO | FBZ | Flybondi | BONDI | Argentina | |
| | FCE | Flycolumbia | FLYCOLUMBIA | Spain | |
| FT | FEG | FlyEgypt | SKY EGYPT | Egypt | |
| | GVG | Flygaktiebolaget Gota Vingar | BLUECRAFT | Sweden | |
| Y2 | GSM | Flyglobespan | GLOBESPAN | United Kingdom | defunct |
| | FPA | Flygprestanda | | Sweden | |
| SX | TOR | FlyGTA Airlines | HOMERUN | Canada | |
| | ETS | Flygtransporter I Nykoping | EXTRANS | Sweden | |
| | INU | Flyguppdraget Backamo | INSTRUCTOR | Sweden | |
| W3 | FYH | Flyhy Cargo Airlines | FLY HIGH | Thailand | |
| | FCR | Flying Carpet Company | FLYING CARPET | Lebanon | |
| | FYG | Flying Service | FLYING GROUP | Belgium | |
| | FGP | Flying-Research Aerogeophysical Center | FLYING CENTER | Russia | |
| TE | LIL | FlyLal | LITHUANIA AIR | Lithuania | defunct |
| | FLK | Flylink Express | FLYLINK | Spain | |
| XY | KNE | Flynas | NAS EXPRESS | Saudi Arabia | |
| LF | NDC | FlyNordic | NORDIC | Sweden | defunct |
| FP | FRE | FlyPelican | PELICAN | Australia | Pelican Airlines Pty Ltd since 1 June 2015 |
| FS | FOX | Flyr | GREENSTAR | Norway | |
| | FTM | Flyteam Aviation | FLYTEAM | United Kingdom | |
| VK | FVK | FlyViking | BALDER | Norway | defunct |
| | FMI | FMI Air | FIRST MYANMAR | Myanmar | |
| | FKS | Focus Air | FOCUS | United States | Omega Air Holdings |
| | FOP | Fokker | | Netherlands | Flight Operations |
| | NOF | Fonnafly | FONNA | Norway | |
| | FOB | Ford Motor Company | FORDAIR | United Kingdom | |
| VY | FOS | Formosa Airlines | | Taiwan | defunct |
| | FOR | Formula One Management | FORMULA | United Kingdom | |
| | FHS | Forth and Clyde Helicopter Services | HELISCOT | United Kingdom | |
| | FXC | Fortunair Canada | AIR FUTURE | Canada | |
| BN | | Forward Air International Airlines | | United States | |
| | FSA | Foster Aviation | FOSTER-AIR | United States | |
| | JFY | Foster Yeoman | YEOMAN | United Kingdom | |
| | FTE | Fotografia F3 | FOTOGRAFIA | Spain | |
| 5F | FIA | FlyOne | FIA | Moldova | Allocated in 2016 |
| 3F | FIE | FlyOne Armenia | ARMRIDER | Armenia | |
| HK | FSC | Four Star Aviation / Four Star Cargo | FOUR STAR | United States | Virgin Islands |
| | WDS | Four Winds Aviation | WINDS | United States | |
| | FXR | Foxair | WILDFOX | Italy | |
| | FDO | France Douanes | FRENCH CUSTOM | France | |
| FH | FHY | Freebird Airlines | FREEBIRD AIR | Turkey | |
| SJ | FOM | Freedom Air | FREE AIR | New Zealand | defunct |
| FP | FRE | Freedom Air | FREEDOM | United States | Aviation Services |
| | FFF | Freedom Air Services | INTER FREEDOM | Nigeria | |
| | FRL | Freedom Airlines | FREEDOM AIR | United States | ICAO Code and callsign withdrawn |
| | FAS | Freedom Airways | FREEDOM AIRWAYS | Cyprus | |
| | FWC | Freeway Air | FREEWAY | Netherlands | Defunct |
| | FRG | Freight Runners Express | FREIGHT RUNNERS | United States | |
| | FAF | Force Aerienne Francaise | FRENCH AIR FORCE | France | |
| | FMY | Aviation Legere De L'Armee De Terre | FRENCH ARMY | France | |
| | FNY | France Marine Nationale | FRENCH NAVY | France | |
| | FRR | Fresh Air | FRESH AIR | Nigeria | |
| | BZY | Fresh Air Aviation | BREEZY | United States | 2015 |
| | FAE | Freshaer | WILDGOOSE | United Kingdom | |
| | FAL | Friendship Air Alaska | FRIENDSHIP | United States | |
| | FLF | Friendship Airlines | FRIEND AIR | Uganda | |
| | FGY | Froggy Corporate Aviation | | Australia | |
| F9 | FFT | Frontier Airlines | FRONTIER FLIGHT | United States | |
| | ITR | Frontier Commuter | OUT BACK | United States | |
| 2F | FTA | Frontier Flying Service | FRONTIER-AIR | United States | |
| | FNG | Frontier Guard | FINNGUARD | Finland | |
| | FUJ | Fujairah Aviation Centre | FUJAIRAH | United Arab Emirates | |
| | CFJ | Fujian Airlines | FUJIAN | China | |
| | GAX | Full Express | GRAND AIRE | United States | |
| | FAM | Fumigación Aérea Andaluza | FAASA | Spain | |
| | FFY | Fun Flying Thai Air Service | FUN FLYING | Thailand | |
| | ROG | FundaciÃ³ Rego | REGO | Spain | |
| | FUN | Funtshi Aviation Service | FUNTSHI | Democratic Republic of the Congo | |
| | FGL | Futura Gael | Applewood | Ireland | defunct |
| FH | FUA | Futura International Airways | FUTURA | Spain | defunct |
| FZ | FDB | Flydubai | SKYDUBAI | UAE | |
| | FWK | Flightworks | | United States | |
| | ACT | Flight Line | AMERICAN CHECK | United States | |
| | FRF | Fleet Air International | FAIRFLEET | Hungary | |
| | FUM | Fuxion Line Mexico | FUNLINE | Mexico | |
| | FWR | FlightAware | FLIGHT AWARE | United States | 3rd party Privacy ICAO Address (PIA) callsign used to obscure true airplane registrations |
| | GML | G & L Aviation | GEEANDEL | South Africa | |
| | DBC | Gemini Air Group | DIAMOND BACK | United States | Allocated in 2014 |
| | GOP | Gospa Air | GOSPA AIR | Mexico | |
| | HGT | GMJ Air Shuttle | HIGHTECH | United States | Private air shuttle for Intel Corporation Employees |
| | GRE | Greenlandcopter | | Denmark | |
| | GMQ | Germania Express | CORGI | Germany | |
| | KNM | GB Helicopters | KINGDOM | United Kingdom | |
| | GCW | Global Air Crew | GLOBALCREW | Denmark | |
| | GBH | Global Avia Handling | | Russia | |
| Y5 | GMR | Golden Myanmar Airlines | GOLDEN MYANMAR | Myanmar | |
| | EXH | G5 Executive | BATMAN | Switzerland | |
| | MTA | GAK/Mitchell Aero | GAK AVIATION | United States | |
| | GGS | GATSA | GATSA | Mexico | |
| | GBX | GB Airlink | ISLAND TIGER | United States | |
| GT | GBL | GB Airways | GEEBEE AIRWAYS | United Kingdom | |
| | GCS | GCS Air Service | GALION | United States | |
| | FFU | GEC Marconi Avionics | FERRANTI | United Kingdom | |
| | GCC | GECAS | GECAS | Ireland | |
| | GEN | GENSA | GENSA-BRASIL | Brazil | |
| | GET | Get High | AIR FLOW | Portugal | |
| | GET | GETRA | GETRA | Equatorial Guinea | ICAO Code no longer allocated |
| | GFW | GFW Aviation | | Australia | |
| | GGT | Trans Island Airways | THUNDERBALL | Bahamas | |
| | GHI | GH Stansted Limited | | United Kingdom | |
| Z5 | GMG | GMG Airlines | GMG | Bangladesh | |
| | GPE | GP Express Airlines | REGIONAL EXPRESS | United States | |
| | GPR | GPM Aeroservicio | GPM AEROSERVICIO | Mexico | |
| | GIB | GR-Avia | GRAVIA | Guinea | |
| | BMK | GST Aero Aircompany | MURAT | Kazakhstan | |
| | GTX | GTA Air | BIG-DEE | United States | |
| | GAH | Ga-Ma Helicoptere | GAMHELICO | France | |
| | GBE | Gabon Express | GABEX | Gabon | |
| | GRT | Gabon-Air-Transport | | Gabon | |
| | GIG | Gacela Air Cargo | GACELA AIR | Mexico | |
| | GFC | Gail Force Express | GAIL FORCE | United States | |
| | GNJ | Gain Jet Aviation | HERCULES JET | Greece | |
| | SWF | Galair International | GALAIR | United Kingdom | |
| | GLS | Galaircervis | GALS | Ukraine | |
| 7O | GAL | Galaxy Air | GALAXY | Kyrgyzstan | |
| | GXY | Galaxy Airlines | GALAX | Japan | |
| | GAS | Galena Air Service | GALENA AIR SERVICE | United States | |
| 1G | | Galileo International | | United States | |
| | GMA | Gama Aviation | GAMA | United Kingdom | |
| | GCH | Gama Aviation Switzerland | GAMA SWISS | Switzerland | |
| GC | GNR | Gambia International Airlines | GAMBIA INTERNATIONAL | Gambia | |
| | NML | Gambia New Millennium Air | NEWMILL | Gambia | |
| | GMJ | Gamisa Aviación | GAMISA | Spain | |
| G7 | GNF | Gandalf Airlines | Gandalf | Italy | |
| | GAN | Gander Aviation | GANAIR | Canada | |
| | GSA | Garden State Airlines | GARDEN STATE | United States | |
| | AHM | Garrison Aviation | AIR HURON | Canada | |
| GA | GIA | Garuda Indonesia | INDONESIA | Indonesia | |
| | GHS | Gatari Hutama Air Services | GATARI | Indonesia | |
| | EGO | Gauteng Air Cargo | GAUTENG | South Africa | |
| | GVN | Gavina | GAVINA | Spain | |
| 4G | GZP | Gazpromavia | GAZPROMAVIA | Russia | |
| | GEE | Geesair | GEESAIR | Canada | |
| | GLX | Gelix Airlines | RUSSIAN BIRD | Russia | |
| GR | GCO | Gemini Air Cargo | GEMINI | United States | |
| | GAB | Gendall Air | GENDALL | Canada | |
| | GDB | Gendarmerie Belge | BELGIAN GENERMERIE | Belgium | |
| | FGN | National Gendarmerie | FRANCE GENDARME | France | |
| | SWK | General Aerospace | SKYWALKER | Canada | |
| | GWS | General Airways | GENAIR | South Africa | |
| | GNZ | General Aviation | GONZO | Poland | |
| | GTH | General Aviation Flying Services | GOTHAM | United States | |
| | XGA | General Aviation Terminal | | Canada | |
| | GMC | General Motors | GENERAL MOTORS | United States | |
| | GNX | Genex | | Belarus | |
| | GSL | Geographic Air Surveys | SURVEY-CANADA | Canada | |
| A9 | TGZ | Georgian Airways | TAMAZI | Georgia | |
| | FGA | Georgian Aviation Federation | GEORGIA FED | Georgia | |
| | GGF | Georgian Cargo Airlines Africa | GEORGIAN AFRICA | Senegal | |
| QB | GFG | Georgian National Airlines | NATIONAL | Georgia | |
| | | Great Barrier Airlines | | New Zealand | Not ICAO allocated – GBA issued for domestic use by the Civil Aviation Authority of New Zealand |
| | GAF | German Air Force | GERMAN AIR FORCE | Germany | |
| | GAM | German Army | GERMAN ARMY | Germany | |
| | GNY | German Navy | GERMAN NAVY | Germany | |
| HE | LGW | German Airways | WALTER | Germany | Former name: Luftfahrtgesellschaft Walter |
| | GHY | German Sky Airlines | GERMAN SKY | Germany | |
| ST | GMI | Germania | GERMANIA | Germany | |
| 4U | GWI | Germanwings | GERMAN WINGS | Germany | |
| | GDN | Gerry's Dnata | | Pakistan | |
| | GFD | Gesellschaft Fur Flugzieldarstellung | KITE | Germany | |
| GP | RIV | APG Airlines | RIVERA | France | |
| | GES | Gestair | GESTAIR | Spain | |
| | GTR | Gestar | STAR GESTAR | Chile | |
| | GJT | Gestión Aérea Ejecutiva | BANJET | Spain | |
| | GHT | Ghadames Air Transport | | Libya | |
| GH | GLP | Globus Airlines | GLOBUS | Russia | |
| GH | GHA | Ghana Airways | GHANA | Ghana | defunct |
| G0 | GHB | Ghana International Airlines | GHANA AIRLINES | Ghana | |
| | NTC | Gibson Aviation | NIGHT CHASE | United States | |
| | RPS | Global Air Charter | RESPONSE | United States | |
| | GAG | Greybird Pilot Academy | GEEBIRD | Denmark | |
| | DMJ | Global Air | DAMOJH | Mexico | defunct |
| | GBS | Global Air Services Nigeria | GLOBAL SERVE | Nigeria | |
| | GLC | Global Aircargo | | Bahrain | |
| | | Global Airways (Turks and Caicos) | | Turks and Caicos Islands | |
| | BSP | Global Airways (BSP) | | Democratic Republic of Congo | |
| | GLB | Global Airways (GLB) | GLO-AIR | United States | Air Castle Corporation |
| | GBB | Global Aviation Operations | GLOBE | South Africa | |
| | GAK | Global Aviation and Services Group | AVIAGROUP | Libya | |
| | GGZ | Global Georgian Airways | GLOBAL GEORGIAN | Georgia | |
| | GLJ | Global Jet Austria | GLOBAL JET AUSTRIA | Austria | |
| | NSM | Global Jet Corporation | THUNDERCLOUD | United States | |
| | SVW | Global Jet Luxembourg | SILVER ARROWS | Luxembourg | |
| | GSK | Global Sky Aircharter | GLOBAL SKY | United States | |
| | GSS | Global Supply Systems | JET LIFT | United Kingdom | |
| | XGS | Global System | | United States | |
| | XGW | Global Weather Dynamics | | United States | |
| | GLW | Global Wings | | Japan | |
| | GJA | Globe Jet | | Lebanon | |
| | GAC | GlobeAir | DREAM TEAM | Austria | |
| 6G | RLX | Go2Sky | RELAX | Slovakia | |
| G8 | GOW | GoAir | GOAIR | India | |
| GK | | Go One Airways | | United Kingdom | Defunct? |
| G7 | GJS | GoJet Airlines | LINDBERGH | United States | |
| | GGE | Gobierno De Guinea Ecuatorial | | Equatorial Guinea | |
| | GOF | Gof-Air | GOF-AIR | Mexico | |
| | GOI | Gofir | SWISS HAWK | Switzerland | |
| G3 | GLO | Gol Transportes Aéreos | GOL TRANSPORTE | Brazil | Brazilian low-cost airline. |
| | GBT | Gold Belt Air Transport | GOLD BELT | Canada | defunct |
| | GDA | GoldAir | AIR PARTNER | United Kingdom | |
| | GDK | Goldeck-Flug | GOLDECK FLUG | Austria | |
| DC | GAO | Golden Air | GOLDEN | Sweden | |
| | GDD | Golden Airlines | GOLDEN AIRLINES | United States | |
| | GPA | Golden Pacific Airlines | GOLDEN PAC | United States | |
| | GRS | Golden Rule Airlines | GOLDEN RULE | Kyrgyzstan | |
| | GLD | Golden Star Air Cargo | GOLDEN STAR | Sudan | |
| | GOS | Goldfields Air Services | | Australia | |
| | GAQ | Golfe Air Quebec | GOLFAIR | Canada | |
| | GLE | Goliaf Air | GOLIAF AIR | São Tomé and Príncipe | |
| | GOM | Gomel Airlines | GOMEL | Belarus | |
| 5Z | GON | Gonini Air Services | GONINI | Suriname | defunct |
| | RDR | Goodridge (UK) Limited | RED STAR | United Kingdom | |
| G1 | | Gorkha Airlines | GORKHA AIRLINES | Nepal | ?ICAO |
| | GOR | Gorlitsa Airlines | GORLITSA | Ukraine | |
| | HKG | Government Flying Service | HONGKONG GOVERNMENT | Hong Kong SAR of China | |
| | GRZ | Government of Zambia Communications Flight | COM FLIGHT | Zambia | |
| | HLD | Grampian Flight Centre | GRANITE | United Kingdom | |
| | GAV | Granada Aviación | GRANAVI | Spain | |
| | GAE | Grand Aire Express | GRAND EXPRESS | United States | |
| | GND | Grand Airways | GRAND VEGAS | United States | |
| | CVU | Grand Canyon Airlines | CANYON VIEW | United States | |
| GV | GUN | Grant Aviation | HOOT | United States | |
| | LMK | Grantex Aviation | LANDMARK | United Kingdom | |
| | GRA | Great American Airways | GREAT AMERICAN | United States | Defunct |
| | GRA | Guardian Air Asset Management | FLEX | South Africa | issued in 2017 |
| ZK | GLA | Great Lakes Airlines | LAKES AIR | United States | |
| | GLU | Great Lakes Airways (Uganda) | LAKES CARGO | Uganda | |
| | GRP | Great Plains Airlines | GREAT PLAINS | United States | |
| IJ | GWL | Great Wall Airlines | GREAT WALL | China | |
| | GWA | Great Western Air | G-W AIR | United States | |
| HB | HGB | Greater Bay Airlines | GREATER BAY | Hong Kong | |
| | HNA | Greek Navy | HELLENIC NAVY | Greece | |
| | GFF | Griffin Aviation | GRIFFIN AIR | Cyprus | |
| | GXA | Grixona | GRIXONA | Moldova | |
| | GZD | Grizodubova Air Company | GRIZODUBOVA AIR | Russia | |
| | HTG | Grossmann Air Service | GROSSMANN | Austria | |
| | GSJ | Grossmann Jet Service | GROSSJET | Czech Republic | |
| | GHV | Ground Handling Service de Mexico | GROUND HANDLING | Mexico | |
| | GPM | Grup Air-Med | GRUPOMED | Spain | |
| | EJC | Grupo De Aviación Ejecutiva | GRUPOEJECUTIVA | Mexico | |
| | TAT | Grupo TACA | TACA-COSTARICA | Costa Rica | |
| | VMM | Grupo Vuelos Mediterraneo | VUELOS MED | Spain | |
| | GMT | Grupo Aéreo Monterrey | GRUPOMONTERREY | Mexico | |
| | GSY | Guard Systems | GUARD AIR | Norway | |
| G6 | BSR | Guine Bissaur Airlines | BISSAU AIRLINES | Guinea-Bissau | |
| | GIJ | Guinea Airways | GUINEA AIRWAYS | Guinea | |
| | GNC | Guinea Cargo | GUINEA CARGO | Equatorial Guinea | |
| J9 | GIF | Guinee Airlines | GUINEE AIRLINES | Guinea | defunct |
| | GEA | Guinea Ecuatorial Airlines | GEASA | Equatorial Guinea | |
| | GIQ | Guinee Paramount Airlines | GUIPAR | Guinea | |
| | CGH | Guizhou Airlines | GUIZHOU | China | |
| | GUS | Guja | GUJA | Mexico | |
| G8 | GUJ | Gujarat Airways | GUJARATAIR | India | |
| | TSU | Gulf & Caribbean Cargo / Contract Air Cargo | TRANSAUTO | United States | |
| | GUF | Gulf African Airlines | GULF AFRICAN | The Gambia | |
| GF | GFA | Gulf Air | GULF AIR | Bahrain | |
| | GAT | Gulf Air Inc | GULF TRANS | United States | |
| | GCN | Gulf Central Airlines | GULF CENTRAL | United States | |
| | SFY | Gulf Flite Center | SKY FLITE | United States | |
| | GPC | Gulf Pearl Air Lines | AIR GULFPEARL | Libya | |
| | GLF | Gulfstream Aerospace | GULFSTREAM TEST | United States | |
| | GFS | Gulfstream Airlines | GULFSTAR | United States | |
| | GFT | Gulfstream International Airlines | GULF FLIGHT | United States | |
| | GUL | Gull Air | GULL-AIR | United States | |
| | GUM | Gum Air | GUM AIR | Suriname | |
| | GDH | Guneydogu Havacilik Isletmesi | RISING SUN | Turkey | |
| GY | | Guyana Airways 2000 | | | |
| | GWN | Gwyn Aviation | GWYN | United Kingdom | |
| H4 | | Héli Sécurité Helicopter Airlines | | France | |
| EO | ALX | Hewa Bora Airways | ALLCONGO | Democratic Republic of the Congo | |
| | AHT | HTA Helicopteros | HELIAPRA | Portugal | |
| | ETI | H-Bird Aviation Services AB | JETHAWK | Sweden | |
| | HSN | H.S.AVIATION CO., LTD. | H.S.AVIATION | Thailand | |
| | HAY | Hamburg Airways | HAMBURG AIRWAYS | Germany | defunct |
| | HCK | Heli-Charter | HELI-CHARTER | United Kingdom | |
| | HTB | Helix-Craft Aviation | HELIX-CRAFT | Panama | 2014 |
| | HAF | Hellenic Air Force | HELLENIC AIR FORCE | Greece | |
| | HRN | Heron Luftfahrt | HERONAIR | Germany | |
| | HYP | Hyperion Aviation | HYPERION | Malta | |
| | HFM | Hi Fly Malta | MOONRAKER | Malta | |
| A5 | HOP | Hop! | AIR HOP | France | |
| | HLA | HC Airlines | HEAVYLIFT | United Kingdom | |
| | HWD | HPM Investments | FLITEWISE | United Kingdom | |
| | KTR | HT Helikoptertransport | COPTER TRANS | Sweden | |
| | | Hacienda Airlines | | United States | defunct - 1957 to July 10, 1962 |
| | FMS | Hadison Aviation | HADI | United States | |
| H6 | HAG | Hageland Aviation Services | HAGELAND | United States | |
| | POW | Hagondale Limited | AIRNET | United Kingdom | |
| HR | HHN | Hahn Air | ROOSTER | Germany | |
| H1 | | Hahn Air Systems | | Germany | |
| HU | CHH | Hainan Airlines | HAINAN | China | |
| 1R | | Hainan Phoenix Information Systems | | China | |
| | HLS | Haiti Air Freight | | Haiti | |
| 2T | HAM | Haiti Ambassador Airlines | | Haiti | |
| | HTI | Haiti International Air | HAITI INTERNATIONAL | Haiti | |
| | HRB | Haiti International Airline | HAITI AIRLINE | Haiti | |
| | HNR | Haiti National Airlines (HANA) | HANAIR | Haiti | |
| | HTN | Haiti North Airline | | Haiti | |
| | HTC | Haiti Trans Air | HAITI TRANSAIR | Haiti | |
| | HBC | Haitian Aviation Line | HALISA | Haiti | |
| | HAJ | Hajvairy Airlines | HAJVAIRY | Pakistan | |
| | HKL | Hak Air | HAK AIRLINE | Nigeria | |
| | HLH | Hala Air | HALA AIR | Sudan | |
| | HCV | Halcyonair | CREOLE | Cape Verde | |
| 4R | HHI | Hamburg International | HAMBURG JET | Germany | |
| | HJL | Hamlin Jet | BIZJET | United Kingdom | |
| | HMM | Hamra Air | HAMRA | United Arab Emirates | |
| | WVA | Hand D Aviation | WABASH VALLEY | United States | |
| | HGR | Hangar 8 | HANG | United Kingdom | |
| | HGD | Hangard Aviation | HANGARD | Mongolia | |
| | HAN | Hansung Airlines | HANSUNG AIR | Republic of Korea | |
| X3 | HLX | Hapag-Lloyd Express | YELLOW CAB | Germany | Became TUI fly Deutschland in 2007 |
| HF | HLF | Hapagfly | HAPAG LLOYD | Germany | Became TUI fly Deutschland in 2007 |
| HB | HAR | Harbor Airlines | HARBOR | United States | |
| HQ | HMY | Harmony Airways | HARMONY | Canada | |
| | NBR | Haughey Air | NORBROOK | United Kingdom | |
| | PYN | Haverfordwest Air Charter Services | POYSTON | United Kingdom | |
| | HAV | Havilah Air Services | HAVILAH | Nigeria | |
| HA | HAL | Hawaiian Airlines | HAWAIIAN | United States | |
| HP | | Hawaiian Pacific Airlines | | United States | defunct |
| | HKR | Hawk Air | AIR HAW | Argentina | |
| | HMX | Hawk De Mexico | HAWK MEXICO | Mexico | |
| BH | | Hawkair | | Canada | defunct since 2016 |
| | HKI | Hawkaire | HAWKEYE | United States | |
| | HZL | Hazelton Airlines | HAZELTON | Australia | Defunct. |
| HN | HVY | Heavylift Cargo Airlines | HEAVY CARGO | Australia | |
| | HVL | Heavylift International | HEAVYLIFT INTERNATIONAL | United Arab Emirates | |
| NS | HBH | Hebei Airlines | HEBEI AIR | China | |
| | HDC | Helcopteros De Cataluna | HELICATALUNA | Spain | |
| | HCB | Helenair (Barbados) | HELEN | Barbados | |
| | HCL | Helenair Corporation | HELENCORP | Saint Lucia | |
| | HHP | Helenia Helicopter Service | HELENIA | Denmark | |
| | HLR | Heli Air Services | HELI BULGARIA | Bulgaria | |
| | ALJ | Heli Ambulance Team | ALPIN HELI | Austria | |
| | HEB | Heli Bernina | HELIBERNINA | Switzerland | |
| | HFR | Heli France | HELIFRANCE | France | |
| | HYH | Heli Hungary | HELIHUNGARY | Hungary | |
| | HLM | Heli Medwest De Mexico | HELIMIDWEST | Mexico | |
| | HLI | Heli Securite | HELI SAINT-TROPEZ | France | |
| | HTP | Heli Trip | HELI TRIP | Mexico | |
| | HLU | Heli Union Heli Prestations | HELI UNION | France | |
| | MCM | Heli-Air-Monaco | HELI AIR | Monaco | |
| | HHE | Heli-Holland | HELI HOLLAND | Netherlands | |
| | HRA | Heli-Iberica | ERICA | Spain | |
| | HIF | Heli-Iberica Fotogrametria | HIFSA | Spain | |
| | HIG | Heli-Inter Guyane | INTER GUYANNE | France | |
| | HLK | Heli-Link | HELI-LINK | Switzerland | |
| | HMC | Heliamerica De Mexico | HELIAMERICA | Mexico | |
| | HEA | Heliavia-Transporte Aéreo | HELIAVIA | Portugal | |
| | CDY | Heliaviation Limited | CADDY | United Kingdom | |
| | HIB | Helibravo Aviacao | HELIBRAVO | Portugal | |
| | HLC | Helicap | HELICAP | France | |
| | COV | Helicentre Coventry | HELICENTRE | United Kingdom | |
| | HEL | Helicol | HELICOL | Colombia | |
| | HCP | Helicopter | HELI CZECH | Czech Republic | |
| | JKY | Helicopter & Aviation Services | JOCKEY | United Kingdom | |
| | MVK | Helicopter Training & Hire | MAVRIK | United Kingdom | |
| | HAP | Helicopteros Aero Personal | HELIPERSONAL | Mexico | |
| | HAA | Helicopteros Agroforestal | AGROFORESTAL | Chile | |
| | HNT | Helicopteros Internacionales | HELICOP INTER | Mexico | |
| | HEN | Helicópteros Y Vehículos Nacionales Aéreos | HELINAC | Mexico | |
| | HHH | Helicsa | HELICSA | Spain | |
| JB | JBA | Helijet | HELIJET | Canada | |
| | HDR | Helikopterdrift | HELIDRIFT | Norway | |
| | SCO | Helikopterservice Euro Air | SWEDCOPTER | Sweden | |
| | OCE | Heliocean | HELIOCEAN | France | |
| ZU | HCY | Helios Airways | HELIOS | Cyprus | defunct since 7 November 2006 |
| | HLP | Helipistas | HELIPISTAS | Spain | |
| | HPL | Heliportugal | HELIPORTUGAL | Portugal | |
| | HEC | Heliservicio Campeche | HELICAMPECHE | Mexico | |
| | HSU | Helisul | HELIS | Portugal | |
| | HSI | Heliswiss | HELISWISS | Switzerland | |
| | HLT | Helitafe | HELITAFE | Mexico | |
| | HIT | Helitalia | HELITALIA | Italy | |
| | OFA | Helitaxi Ofavi | OFAVI | Mexico | |
| | HLT | Helitours | HELITOURS | Sri Lanka | |
| 9I | HTA | Helitrans | SCANBIRD | Norway | |
| | HTS | Helitrans Air Service | HELITRANS | United States | |
| | HLW | Heliworks | HELIWORKS | Chile | |
| HJ | HEJ | Hellas Jet | HELLAS JET | Greece | ceased operation in 2010 |
| HW | FHE | Hello | FLYHELLO | Switzerland | |
| | HLG | Helog | HELOG | Switzerland | |
| 2L | OAW | Helvetic Airways | HELVETIC | Switzerland | |
| | HMS | Hemus Air | HEMUS AIR | Bulgaria | |
| | HAC | Henebury Aviation | | Australia | |
| | SSH | Heritage Flight (Valley Air Services) | SNOWSHOE | United States | |
| | MRX | Herman's Markair Express | SPEEDMARK | United States | |
| | HED | Heritage Aviation Developments | FLAPJACK | United Kingdom | |
| UD | HER | Hex'Air | HEX AIRLINE | France | |
| | HHS | Hi-Jet Helicopter Services | HIJET | Suriname | |
| 5K | HFY | Hi Fly | SKY FLYER | Portugal | |
| | HLB | High-Line Airways | HIGH-LINE | Canada | |
| | HWY | Highland Airways | HIWAY | United Kingdom | |
| H9 | HIM | Himalaya Airlines | HIMALAYA | Nepal | |
| H7 | HYM | HiSky | SKY MOLDOVA | Moldova | |
| H4 | HYS | HiSky Europe | SKY EUROPE | Romania | |
| | HSH | Hispánica de Aviación | HASA | Spain | |
| | HIS | Hispaniola Airways | HISPANIOLA | Dominican Republic | |
| VM | VMS | His Majesty King Maha Vajiralongkorn | VICTOR MIKE | Thailand | holding airline, renamed on his accession. |
| | HGA | Hogan Air | HOGAN AIR | United States | |
| | NTH | Hokkaido Air System | NORTH AIR | Japan | |
| | ABH | Hokuriki-Koukuu Company | | Japan | |
| H5 | HOA | Hola Airlines | HOLA | Spain | |
| | HIN | Holding International Group | HOLDING GROUP | Mexico | |
| | HOL | Holiday Airlines (US Airline) | HOLIDAY | United States | |
| HC | HCC | Holidays Czech Airlines | CZECH HOLIDAYS | Czech Republic | |
| | HTR | Holstenair Lubeck | HOLSTEN | Germany | |
| | HMV | Homac Aviation | HOMAC | Luxembourg | |
| | HAS | Honduras Airlines | HONDURAS AIR | Honduras | |
| HX | CRK | Hong Kong Airlines | BAUHINIA | Hong Kong | |
| RH | HKC | Hong Kong Air Cargo | MASCOT | Hong Kong | |
| UO | HKE | Hong Kong Express Airways | HONGKONG SHUTTLE | Hong Kong | |
| A6 | HTU | Hongtu Airlines | HONGLAND | China | |
| | HEX | Honiara Cargo Express | HONIARA CARGO | Solomon Islands | |
| H1 | | Hooters Air | Hooters Air | United States | The airline was established in 2003 and started operations on March 6, 2003. On April 17, 2006, Hooters Air ceased operations, halting scheduled Public Charter service and refunding tickets. |
| | HPJ | Hop-A-Jet | HOPA-JET | United States | |
| HH | | Hope Air | HOPE AIR | Canada | |
| QX | QXE | Horizon Air | HORIZON AIR | United States | |
| | KOK | Horizon Air Service | KOKO | United States | |
| | HSM | Horizon Air for Transport and Training | ALOFUKAIR | Libya | |
| | HOR | Horizon Air-Taxi | HORIZON | Switzerland | |
| BN | HZA | Horizon Airlines | HORIZON | Australia | defunct |
| | HPS | Horizon Plus | HORIZON PLUS | Bangladesh | |
| | HUD | Horizons Unlimited | HUD | United States | |
| | HOZ | Horizontes Aéreos | HORIZONTES AEREOS | Mexico | |
| | HDI | Hoteles Dinamicos | DINAMICOS | Mexico | |
| | HHO | Houston Helicopters | HOUSTON HELI | United States | |
| | GGV | Houston Jet Services | GREGG AIR | Austria | |
| | OZU | Hozu-Avia | HOZAVIA | Kazakhstan | |
| | HUB | Hub Airlines | HUB | United States | |
| | HUS | Huessler Air Service | HUESSLER | United States | |
| | GMH | Hughes Aircraft Company | HUGHES EXPRESS | United States | |
| HJ | USW | HumoAir | AKSAR | Uzbekistan | |
| | HUV | Hunair Hungarian Airlines | SILVER EAGLE | Hungary | |
| | HUF | Hungarian Air Force | HUNGARIAN AIRFORCE | Hungary | |
| HW | UBD | FlyErbil | HAWLER | Iraqi Kurdistan | |
| | HYA | Hyack Air | HYACK | Canada | |
| | HYC | Hydro Air Flight Operations | HYDRO CARGO | South Africa | |
| | HYD | Hydro-Québec | HYDRO | Canada | |
| | HKB | Hawker Beechcraft | CLASSIC | United States | |
| MR | MML | Hunnu Air | TRANS MONGOLIA | Mongolia | |
| | RPX | HD Air Ltd | RAPEX | United Kingdom | |
| | SRD | HM Coastguard | COASTGUARD | United Kingdom | |
| | SRG | HM Coastguard | RESCUE | United Kingdom | Search and Rescue |
| | WHR | Hummingbird Helicopter Service | WHIRLEYBIRD | United States | |
| I4 | EXP | Island Air Express | ISLAND EXPRESS | United States | 2014 |
| | IWL | Island Wings | | Bahamas | 2014 |
| IK | KAR | Ikar | IKAR | Russian Federation | |
| | ICN | Iconair | | Pakistan | |
| | IAC | INTERCHARTER | Romania | |
| | ITC | International Air Carrier Association | | Belgium | |
| | IDG | IDG Technology Air | INDIGO | Czech Republic | |
| | IFL | IFL Group | EIFEL | United States | |
| | RDE | II Lione Alato Arl | FLIGHT RED | United Kingdom | |
| | IJM | IJM International Jet Management | JET MANAGEMENT | Austria | |
| | IKK | IKI International Airlines | IKIAIR | Japan | |
| | IKN | IKON FTO | IKON | Germany | |
| | BLU | IMP Aviation Services | BLUENOSE | Canada | |
| | XGG | IMP Group Aviation Services | | Canada | |
| 1F | | INFINI Travel Information | | Japan | Computer Reservation System |
| | IPA | IPEC Aviation | IPEC | Australia | |
| | IPM | IPM Europe | SHIPEX | United Kingdom | |
| | LVB | IRS Airlines | SILVERBIRD | Nigeria | |
| | ISD | ISD Avia | ISDAVIA | Ukraine | |
| 1U | | ITA Software | | United States | Computer reservation system |
| | FDF | IVV Femida | | Russia | |
| IB | IBE | Iberia Airlines | IBERIA | Spain | |
| II | CSQ | IBC Airways | CHASQUI | United States | |
| I2 | IBS | Iberia Express | IBEREXPRESS | Spain | Charter service, low cost carrier for EU flights of Iberia operating only A320s |
| | IBR | Ibertour Servicios Aéreos | IBERTOUR | Spain | |
| | IBT | Ibertrans Aérea | IBERTRANS | Spain | |
| TY | IWD | Iberworld | IBERWORLD | Spain | |
| FW | IBX | Ibex Airlines | IBEX | Japan | |
| | IBC | Ibicenca Air | IBICENCA | Spain | |
| | AKI | Ibk-Petra | | Sudan | |
| 0C | IBL | IBL Aviation | CATOVAIR | Mauritius | |
| | BBL | IBM Euroflight Operations | BLUE | Switzerland | |
| | YYY | ICAO | | | Used by airlines without a specific code |
| C3 | IPR | Independent Carrier (ICAR) | ICAR | Ukraine | |
| | ICA | Icaro | ICARFLY | Italy | |
| | ICD | Icaro Air | ICARO | Ecuador | Defunct 2011 |
| | IUS | Icarus | ICARUS | Italy | |
| | CIC | ICC Canada | AIR TRADER | Canada | |
| | ICJ | Icejet | ICEJET | Iceland | |
| HC | | Iceland Express | | Iceland | defunct |
| FI | ICE | Icelandair | ICEAIR | Iceland | |
| | ICG | Icelandic Coast Guard | ICELAND COAST | Iceland | |
| | RAC | Icar Air | TUZLA AIR | Bosnia and Herzegovina | |
| | FRC | Icare Franche Compte | FRANCHE COMPTE | France | |
| | IFM | Ifly | ICOPTER | Greece | |
| | IKR | Ikaros DK | IKAROS | Denmark | |
| | CIO | Il Ciocco International Travel Service | CIOCCO | Italy | |
| | ILV | Il-Avia | ILAVIA | Russia | |
| | IDL | Ildefonso Redriguez | ILDEFONSO | Mexico | |
| V8 | IAR | Iliamna Air Taxi | ILIAMNA AIR | United States | |
| | ILP | Ilpo Aruba Cargo | | Aruba | |
| | ILL | Ilyich-Avia | ILYICHAVIA | Ukraine | |
| | IMR | Imaer | IMAER | Portugal | |
| | ITX | Imair Airlines | IMPROTEX | Azerbaijan | |
| | PNX | Imperial Airways | PHOENIX | United States | ICAO code in use by another company, call sign no longer allocated |
| | IMG | Imperial Cargo Airlines | IMPERIAL AIRLINES | Ghana | |
| | IMT | Imtrec Aviation | IMTREC | Cambodia | |
| DH | IDE | Independence Air | INDEPENDENCE AIR | United States | defunct |
| | IDP | Independent Air Freighters | INDEPENDENT | Australia | |
| I7 | IOA | IndiaOne Air | INDIA FIRST | India | |
| 6E | IGO | IndiGo | IFLY | India | InterGlobe Aviation |
| | IIL | India International Airways | INDIA INTER | India | |
| | IFC | Indian Air Force | INDIAN AIRFORCE | India | |
| IC | IAC | Indian Airlines | INDAIR | India | |
| | IDR | Indicator Company | INDICATOR | Hungary | |
| I9 | IBU | Indigo Airlines | INDIGO BLUE | United States | |
| VP | AXC | Indochina Airlines | AIRSPUP | Vietnam | defunct |
| | IDA | Indonesia Air Transport | INTRA | Indonesia | |
| QZ | AWQ | Indonesia AirAsia | WAGON AIR | Indonesia | |
| IO | IAA | Indonesian Airlines | INDO LINES | Indonesia | |
| | IPN | Industri Pesawat Terbang Nusantara | NUSANTARA | Indonesia | |
| | ITN | Industrias Titan | TITANLUX | Spain | |
| | FFI | Infinit Air | INFINIT | Spain | |
| | INS | Inflite The Jet Centre | | United Kingdom | |
| | IVA | Innotech Aviation | INNOTECH | Canada | |
| | INC | Insel Air International | INSELAIR | Netherlands Antilles | |
| | ICC | Institut Cartogràfic de Catalunya | CARTO | Spain | |
| | INT | Intair | INTAIRCO | Canada | |
| | INL | Intal Avia | INTAL AVIA | Kyrgyzstan | |
| | FFL | Intavia Limited | | United Kingdom | |
| | XRA | Intensive Air | INTENSIVE | South Africa | |
| | ITW | Inter Air | INTER WINGS | Bulgaria | |
| | INX | Inter Express | INTER-EURO | Turkey | |
| | IIC | Inter Island Air Charter | | Bahamas | 2014 |
| H4 | IIN | Inter Island Airways | | Cape Verde | |
| | CAR | Inter RCA | QUEBEC ROMEO | Central African Republic | |
| | NTT | Inter Tropic Airlines | INTER-TROPIC | Sierra Leone | |
| | TCU | Inter Tropical Aviation | TROPAIR | Suriname | Defunct 2001 |
| | ITA | Inter-Air | CAFEX | United States | |
| | ICN | Inter-Canadian | INTER-CANADIAN | Canada | |
| | UGL | Inter-Island Air | UGLY VAN | United States | |
| | IMA | Inter-Mountain Airways | INTER-MOUNTAIN | United States | |
| | ITS | Inter-State Aviation | INTER-STATE | United States | |
| D6 | ILN | Interair South Africa | INLINE | South Africa | |
| | NTE | Interaire | INTERMEX | Mexico | |
| ZA | SUW | Interavia Airlines | ASTAIR | Russia | |
| | IVT | Interaviatrans | INTERAVIA | Ukraine | |
| JY | IWY | InterCaribbean Airways | ISLANDWAYS | Turks and Caicos Islands | Name changed from Interisland Airways Limited and Air Turks & Caicos |
| RS | ICT | Intercontinental de Aviación | CONTAVIA | Colombia | |
| | ICP | Intercopters | CHOPER | Spain | |
| | IFT | Interflight | INTERFLIGHT | United Kingdom | |
| | IJT | Interflight (Learjet) | | United Kingdom | |
| | RFL | Interfly | INFLY | Italy | |
| | IFF | Interfreight Forwarding | INTERFREIGHT | Sudan | |
| | IGN | Interguide Air | DIVINE AIR | Nigeria | |
| | ISN | Interisland Airlines | TRI-BIRD | Philippines | |
| | IWY | Interisland Airways Limited | ISLANDWAYS | Turks and Caicos Islands | Name changed to Air Turks and Caicos |
| 4O | AIJ | Interjet | ABC AEROLINEAS | Mexico | |
| | IHE | Interjet Helicopters | INTERCOPTER | Greece | |
| | IJW | Interjet Inc. | JET WEST | United States | 2015 |
| ID | ITK | Interlink Airlines | INTERLINK | South Africa | |
| | IAK | International Air Cargo Corporation | AIR CARGO EGYPT | Egypt | |
| | EXX | International Air Corporation | EXPRESS INTERNATIONAL | United States | |
| N/A | NCC | T3 Aviation, Inc. | STARFLEET | United States | 2020 |
| | IAX | International Air Services | INTERAIR SERVICES | Liberia | |
| | IBY | International Business Aircraft | CENTRAL STAGE | United States | |
| | ICS | International Charter Services | INTERSERVI | Mexico | |
| | ICX | International Charter Xpress | INTEX | United States | Defunct 1994 |
| | RED | International Committee of the Red Cross | RED CROSS | Switzerland | |
| | IIG | International Company for Transport, Trade and Public Works | ALDAWLYH AIR | Libya | |
| | IFX | International Flight Training Academy | IFTA | United States | |
| | IJA | International Jet Aviation Services | I-JET | United States | |
| | HSP | International Jet Charter | HOSPITAL | United States | The Flying Hospital |
| | THN | International Security Assistance Force | ATHENA | Canada | |
| | RSQ | International SOS Windhoek | SKYMEDIC | Namibia | |
| | ISF | International Stabilisation Assistance Force | | United Kingdom | |
| | ITH | International Trans-Air | INTRANS NIGERIA | Nigeria | |
| | IPT | Interport Corporation | INTERPORT | United States | |
| | IKY | Intersky Bulgary | GENERAL SKY | Bulgaria | |
| 3L | ISK | Intersky | INTERSKY | Austria | Defunct |
| I4 | FWA | Interstate Airlines | FREEWAYAIR | Netherlands | Defunct |
| | ITU | Intervuelos | INTERLOS | Mexico | |
| | INV | Inversija | INVER | Latvia | |
| | IND | Iona National Airways | IONA | Ireland | |
| | IOA | Iowa Airways | IOWA AIR | United States | |
| IR | IRA | Iran Air | IRANAIR | Iran | |
| EP | IRC | Iran Aseman Airlines | ASEMAN | Iran | |
| B9 | IRB | Iran Airtour | AIRTOUR | Iran | |
| | IRG | Iranian Naft Airlines | NAFT | Iran | |
| IA | IAW | Iraqi Airways | IRAQI | Iraq | |
| | BIS | Irbis Air | IRBIS | Kazakhstan | |
| | IRL | Irish Air Corps | IRISH | Ireland | |
| | RDK | Irish Air Transport | IRISH TRANS | Ireland | |
| | XMR | Irish Aviation Authority | AUTHORITY | Ireland | |
| IH | MZA | Irtysh Air | IRTYSH AIRLINES | Kazakhstan | Old IATA code: IT; old ICAO code: IRT |
| | KCE | Irving Oil | KACEY | Canada | |
| | ISI | Island Air | ISLANDMEX | Mexico | |
| | ILF | Island Air Charters | ISLAND FLIGHT | United States | |
| | XYZ | Island Air Express | RAINBIRD | United States | |
| | ISA | Island Airlines | | United States | |
| | SOY | Island Aviation | SORIANO | Philippines | |
| | DQA | Island Aviation Services | | Maldives | |
| | IOM | Island Aviation and Travel | ISLE AVIA | United Kingdom | |
| 2S | SDY | Island Express | SANDY ISLE | United States | |
| | MTP | Island Helicopters | METROCOPTER | United States | |
| | ILC | ILAS Air | | Japan | |
| | IAJ | Islandair Jersey | JARLAND | United Kingdom | |
| CN | | Islands Nationair | | Papua New Guinea | |
| | ICB | Icebird Airline | ICEBIRD | Iceland | |
| IF | ISW | Islas Airways | PINTADERA | Spain | |
| | IGS | Isle Grande Flying School | ISLA GRANDE | United States | |
| WC | ISV | Islena De Inversiones | | Honduras | |
| | IOS | Isles of Scilly Skybus | SCILLONIA | United Kingdom | |
| | IAI | Israel Aircraft Industries | ISRAEL AIRCRAFT | Israel | |
| | IAF | Israeli Air Force | | Israel | |
| 6H | ISR | Israir | ISRAIR | Israel | |
| | IST | Istanbul Airlines | ISTANBUL | Turkey | |
| AZ | ITY | ITA Airways | ITARROW | Italy | |
| FS | ACL | Itali Airlines | SPADA | Italy | Former name: Transporti Aerei Italiani; former IATA Code: 9X*; former ICAO code: ACO |
| | IAM | Italian Air Force | ITALIAN AIRFORCE | Italy | |
| | IEI | Italian Army | ITALIAN ARMY | Italy | |
| | GCI | Italian Coast Guard | ITALIAN COAST GUARD | Italy | |
| | MMI | Italian Navy | ITALIAN NAVY | Italy | |
| | IFS | Italy First | RIVIERA | Italy | |
| GI | IKA | Itek Air | ITEK-AIR | Kyrgyzstan | ?ICAO confirmed; IATA not |
| | IVS | Ivoire Aero Services | IVOIRE AERO | Ivory Coast | |
| | IVW | Ivoire Airways | IVOIRAIRWAYS | Ivory Coast | |
| | IJE | Ivoire Jet Express | IVOIRE JET | Ivory Coast | |
| | OIC | Iwamoto Crane Co Ltd | | Japan | |
| | IXR | Ixair | X-BIRD | France | |
| H9 | IZM | Izair | IZMIR | Turkey | |
| | IZA | Izhavia | IZHAVIA | Russia | |
| | JTN | | JET TEST | United States | |
| | JGJ | Jinggong Jet | GLOBAL JINGGONG | China | 2014, 2023 |
| | JNY | Journey Aviation | ROCKBAND | United States | 2023: Callsign "ROCKBAND"; Former Call Sign/Telephony Designator: UNIJET-ROCKBAND (2014) |
| | JKR | Justice Air Charter | JOKER | United States | Trading name for Reliant Aviation, allocated in 2014 |
| | JWD | Jayawijaya Dirgantara | | Indonesia | |
| | JCB | JCB (heavy equipment manufacturer) | JAYSEEBEE | United Kingdom | |
| | RFX | J P Hunt Air Carriers | REFLEX | United States | J P Hunt Air Carriers |
| XM | | J-Air | J AIR | Japan | |
| JC | JEX | JAL Express | JANEX | Japan | |
| JO | JAZ | JALways | JALWAYS | Japan | |
| | JDA | JDAviation | JAY DEE | United Kingdom | |
| | JDP | JDP Lux | RED PELICAN | Luxembourg | |
| | JHM | JHM Cargo Expreso | | Costa Rica | |
| | TQM | JM Family Aviation | TACOMA | United States | |
| MT | JMC | JMC Airlines | JAYEMMSEE | United Kingdom | |
| 1M | | JSC Transport Automated Information Systems | | Russia | |
| | JSJ | JS Air | JS CHARTER | Pakistan | |
| | JES | JS Aviation | JAY-ESS AVIATION | Mexico | |
| | JCK | Jackson Air Services | JACKSON | Canada | |
| JI | JAE | Jade Cargo International | JADE CARGO | China | defunct |
| | JAW | Jamahiriya Airways | JAW | Libya | |
| | JMB | Jambo Africa Airlines | JAMBOAFRICA | Democratic Republic of Congo | |
| | WWW | Janet | JANET | United States | de facto name |
| | FJX | Jet Sky Cargo and Air Charter | | Kenya | |
| | JAK | Jana-Arka | YANZAR | Kazakhstan | |
| | JAX | Janair | JANAIR | United States | |
| 3X | JAC | Japan Air Commuter | COMMUTER | Japan | |
| | JSV | Japan Aircraft Service | | Japan | |
| JL | JAL | Japan Airlines | JAPANAIR | Japan | Japan Airlines International |
| JL | JAL | Japan Airlines Domestic | J-BIRD | Japan | defunct |
| EG | JAA | Japan Asia Airways | ASIA | Japan | defunct |
| NU | JTA | Japan Transocean Air | JAI OCEAN | Japan | |
| JA | JAT | JetSMART | ROCKSMART | Chile | |
| JZ | JAP | JetSMART Perú | RED SMART | Peru | |
| WJ | JES | JetSMART Argentina | SMARTBIRD | Argentina | |
| JU | JAT | Jat Airways | JAT | Serbia | |
| VJ | JTY | Jatayu Airlines | JATAYU | Indonesia | |
| J9 | JZR | Jazeera Airways | JAZEERA | Kuwait | |
| 7C | JJA | Jeju Air | JEJU AIR | Republic of Korea | |
| | JNY | Jenney Beechcraft | JENAIR | United States | |
| | XLD | Jeppesen Data Plan | | United States | |
| | JPN | Jeppesen UK | JETPLAN | United Kingdom | |
| O2 | JEA | OLT Express | JETA | Poland | defunct, funded by acquisition of Jet Air and YES Airways |
| | JSI | Jet Air Group | SISTEMA | Russia | JSC |
| 9W | JAI | Jet Airways | JET AIRWAYS | India | |
| QJ | | Jet Airways | | United States | |
| | JTX | Jet Aspen Air Lines | JET ASPEN | United States | |
| PP | PJS | Jet Aviation | JETAVIATION | Switzerland | |
| | BZF | Jet Aviation Business Jets | BIZFLEET | United States | |
| | JAS | Jet Aviation Flight Services | JET SETTER | United States | |
| | JCF | Jet Center Flight Training | JET CENTER | Spain | |
| | JCT | Jet Charter | JET CHARTER | United States | |
| | JCX | Jet Connection | JET CONNECT | Germany | defunct |
| | DWW | Jet Courier Service | DON JUAN | United States | |
| | JED | Jet East International | JET EAST | United States | defunct |
| | JEI | Jet Executive International Charter | JET EXECUTIVE | Germany | |
| | RZA | Jet Fighter Flights | RAZOR | Australia | |
| | CFT | Jet Freighters | CASPER FREIGHT | United States | |
| | JGD | Jet G&D Aviation | JET GEE-AND-DEE | Israel | |
| | MJL | Jet Line International | MOLDJET | Moldova | |
| | JEK | Jet Link | JET OPS | Israel | |
| | HTL | Jet Linx Aviation | HEARTLAND | United States | |
| | JTL | Jet Linx Aviation | JET LINX | United States | |
| | JNR | Jet Norte | JET NORTE | Mexico | |
| | JRN | Jet Rent | JET RENT | Mexico | |
| | JDI | Jet Story | JEDI | Poland | Formerly: Jet Service |
| 3K | JSA | Jetstar Asia Airways | JETSTAR ASIA | Singapore | |
| | JDI | Jet Story | JEDI | Poland | former Blue Jet |
| | JSM | Jet Stream | JET STREAM | Moldova | |
| | VTB | Jet Stream Charter KFT. | SUXAIR | Hungary | 2023 |
| | JSS | Jet Stream International | | Pakistan | 2023 |
| | JTF | Jet Time | JETFIN | Finland | 2014, 2023 |
| | JTC | Jet Trans Aviation | JETRANS | Ghana | |
| | JTT | Jet-2000 | MOSCOW JET | Russia | |
| | OPS | Jet-Ops | OPS-JET | United Arab Emirates | |
| | JSH | Jet-stream | STREAM AIR | Hungary | |
| LS | EXS | Jet2.com | CHANNEX | United Kingdom | Formerly Channel Express |
| | JFU | Jet4You | ARGAN | Morocco | |
| | OSW | JetAfrica Eswatini | BEVO | Eswatini | |
| B6 | JBU | JetBlue Airways | JETBLUE | United States | |
| | JMG | JetMagic | JET MAGIC | Ireland | Defunct |
| | JMK | Jetmagic | | Malta | Defunct, Not Many Flights |
| JF | JAA | Jet Asia Airways | JET ASIA | Thailand | |
| | JAF | Jetairfly | BEAUTY | Belgium | |
| | JTL | Jetall Holdings | FIREFLY | Canada | |
| | JAG | Jetalliance | JETALLIANCE | Austria | |
| 0J | JCS | Jetclub | JETCLUB | Switzerland | |
| | QNZ | Jetconnect | QANTAS JETCONNECT | New Zealand | |
| | UEJ | Jetcorp | JETCORP | United States | (United Executive Jet) |
| | JCC | Jetcraft Aviation | JETCRAFT | Australia | |
| | JXA | Jetex Aviation | | Lebanon | |
| | JEF | Jetflite | JETFLITE | Finland | |
| | JFL | Jetfly Airlines | LINEFLYER | Austria | |
| | JFA | Jetfly Aviation | MOSQUITO | Luxembourg | |
| | JIC | Jetgo International | JIC-JET | Thailand | |
| | JLX | Jetlink Express | KEN JET | Kenya | |
| | JLH | Jetlink Holland | | Netherlands | Defunct, ICAO code in use by another company |
| | JNL | JetNetherlands | JETNETHERLANDS | Netherlands | |
| | JNV | Jetnova de Aviación Ejecutiva | JETNOVA | Spain | |
| | JPO | Jetpro | JETPRO | Mexico | |
| | MDJ | Jetran Air | JETRAN AIR | Romania | |
| | JRI | Jetrider International | JETRIDER | United Kingdom | |
| | JEJ | Jets Ejecutivos | MEXJETS | Mexico | |
| | JEP | Jets Personales | JET PERSONALES | Spain | |
| | JSE | Jets Y Servicios Ejecutivos | SERVIJETS | Mexico | |
| SG | JGO | JetsGo | JETSGO | Canada | defunct |
| JQ | JST | Jetstar | JETSTAR | Australia | |
| GK | JJP | Jetstar Japan | ORANGE LINER | Japan | |
| JM | JKT | Jetstar Hong Kong Airways | KAITAK | China | |
| | JXT | Jetstream Executive Travel | VANNIN | United Kingdom | |
| | RSP | JetSuite | REDSTRIPE | United States | |
| | JPQ | Jett Paqueteria | JETT PAQUETERIA | Mexico | |
| JX | JEC | Jett8 Airlines Cargo | TAIPAN | Singapore | defunct |
| JO | JTD | Jettime | JETTIME | Denmark | |
| | JTN | Jet Test Intl. | JET TEST | United States | |
| | JWY | Jetways of Iowa | JETWAYS | United States | |
| GX | JXX | JetX Airlines | JETBIRD | Iceland | |
| | JIB | Jibair | JIBAIRLINE | Djibouti | |
| | JSW | Jigsaw Project | JIGSAW | United Kingdom | Bristow Helicopters |
| | HKN | Jim Hankins Air Service | HANKINS | United States | |
| | RAS | Jim Ratliff Air Service | SHANHIL | United States | |
| LJ | JNA | Jin Air | JIN AIR | South Korea | |
| | JDG | Joanas Avialinijos | LADYBLUE | Lithuania | |
| | JBR | Job Air | JOBAIR | Czech Republic | |
| | JHN | Johnson Air | AIR JOHNSON | United States | |
| | JON | Johnsons Air | JOHNSONSAIR | Ghana | |
| | JMJ | Johnston Airways | JOHNSTON | United States | |
| | JMM | Joint Military Commission | JOICOMAR | Sudan | |
| | JMT | Jomartaxi Aereo | JOMARTAXI | Mexico | |
| | ODI | Jonsson, H Air Taxi | ODINN | Iceland | |
| R5 | JAV | Jordan Aviation | JORDAN AVIATION | Jordan | |
| J4 | JCI | Jordan International Air Cargo | | Jordan | |
| | JVK | Jorvik | ISLANDIC | Iceland | |
| | ENZ | Jota Aviation | ENZO | United Kingdom | |
| | JNJ | Journey Jet | JOURNEY JET | Thailand | |
| XE | JSX | JSX (airline) | BIGSTRIPE | United States | |
| | JUR | Ju-Air | JUNKERS | Switzerland | |
| | JFS | Juanda Flying School | JAEMCO | Indonesia | |
| | JUC | Juba Cargo Services & Aviation Company | JUBA CARGO | Sudan | |
| 6J | JUB | Jubba Airways | JUBBA | Somalia | |
| | DKE | Jubilee Airways | DUKE | United Kingdom | |
| HO | DKH | Juneyao Airlines | AIR JUNEYAO | China | 2023 |
| | JSY | Jung Sky | | Croatia | |
| | MEY | Justair Scandinavia | MELODY | Sweden | |
| | DOJ | Justice Prisoner and Alien Transportation System | JUSTICE | United States | |
| | KTA | K2 Airways | | Pakistan | |
| | KSA | K S Avia | SKY CAMEL | Latvia | |
| | KCR | Kolob Canyons Air Services | KOLOB | United States | |
| KW | KHK | Kharkiv Airlines | SUNRAY | Ukraine | |
| | KGZ | Kyrgyz Airlines | BERMET | Kyrgyzstan | |
| | KDC | K D Air Corporation | KAY DEE | Canada | |
| | KMI | K-Mile Air | KAY-MILE AIR | Thailand | |
| KD | KLS | Kalstar Aviation | KALSTAR | Indonesia | |
| KD | KNI | KD Avia | KALININGRAD AIR | Russia | |
| WA | KLC | KLM Cityhopper | CITY | Netherlands | |
| | KLH | KLM Helicopter | KLM HELI | Netherlands | |
| KL | KLM | KLM | KLM | Netherlands | |
| N2 | QNK | Kabo Air | KABO | Nigeria | |
| | KMC | Kahama Mining Corporation | KAHAMA | Tanzania | |
| KI | KAI | KaiserAir | KAISER | United States | Operates B737-500, B737-700, B737-800 |
| K4 | CKS | Kalitta Air | CONNIE | United States | Operates B747-400's, B767-300ER's, B777F |
| K9 | KFS | Kalitta Charters | KALITTA | United States | Operates Lear 25s, 35s, 36s Falcon 20s, CL601 |
| CB* | KII | Kalitta Charters II | DRAGSTER | United States | Operates B727-200's, DC9-15 & 30, B737-400's |
| | KES | Kallat El Saker Air Company | KALLAT EL SKER | Libya | |
| RQ | KMF | Kam Air | KAMGAR | Afghanistan | |
| E2 | KMP | Kampuchea Airlines | KAMPUCHEA | Cambodia | IATA was KT |
| | KIZ | Kanaf-Arkia Airlines | | Israel | |
| | KHE | Kanfey Ha'emek Aviation | KANFEY HAEMEK | Israel | |
| | KSU | Kansas State University | K-STATE | United States | |
| V2 | AKT | Karat | AVIAKARAT | Russia | |
| | KRB | Karibu Airways Company | KARIBU AIR | Tanzania | |
| | KLG | Karlog Air Charter | KARLOG | Denmark | defunct |
| | KAJ | Karthago Airlines | KARTHAGO | Tunisia | |
| | KAE | Kartika Airlines | KARTIKA | Indonesia | |
| | KTV | Kata Transportation | KATAVIA | Sudan | |
| | KTK | Katekavia | KATEKAVIA | Russia | |
| | KAT | Kato Airline | KATO-AIR | Norway | |
| KV | MVD | Kavminvodyavia | AIR MINVODY | Russia | |
| | XKA | Kavouras Inc | | United States | |
| | KRN | Kaz Agros Avia | ANTOL | Kazakhstan | |
| | KAW | Kaz Air West | KAZWEST | Kazakhstan | |
| | KAO | Kazan Aviation Production Association | KAZAVAIA | Russia | |
| | KPH | Kazan Helicopters | KAMA | Russia | |
| | KKA | Kazavia | KAKAIR | Kazakhstan | |
| | KZS | Kazaviaspas | SPAKAZ | Kazakhstan | |
| 3Q | KCH | KC International Airlines | CAM AIR | Cambodia | |
| | JFK | Keenair Charter - | KEENAIR | United Kingdom | |
| | KLX | Kelix Air | KELIX | Nigeria | |
| | FKL | Kelner Airways | KELNER | Canada | |
| KW | KFA | Kelowna Flightcraft Air Charter | FLIGHTCRAFT | Canada | |
| | KDA | Kendell Airlines | KENDELL | Australia | defunct |
| M5 | KEN | Kenmore Air | KENMORE | United States | |
| | KBA | Kenn Borek Air | BOREK AIR | Canada | |
| | KAH | Kent Aviation | DEKAIR | Canada | |
| KQ | KQA | Kenya Airways | KENYA | Kenya | |
| | KVS | Kevis | KEVIS | Kazakhstan | |
| ZN | KEY | Key Airlines | KEY AIR | United States | |
| KG | LYM | Key Lime Air | KEY LIME | United States | |
| | FTP | Keystone Aerial Surveys | FOOTPRINT | United States | |
| BZ | KEE | Keystone Air Service | KEYSTONE | Canada | |
| K6 | KZW | Khalifa Airways | KHALIFA AIR | Algeria | |
| | WKH | Kharkov Aircraft Manufacturing Company | WEST-KHARKOV | Ukraine | |
| | KHR | Khazar | KHAZAR | Turkmenistan | |
| | KHP | Khoezestan Photros Air Lines | PHOTROS AIR | Iran | |
| | KRV | Khoriv-Avia | KHORIV-AVIA | Ukraine | |
| X9 KO | KHO | Khors Aircompany | AIRCOMPANY KHORS | Ukraine | defunct |
| | KHY | Khyber Afghan Airlines | KHYBER | Afghanistan | |
| | UAK | Kiev Aviation Plant | AVIATION PLANT | Ukraine | |
| | KNG | King Aviation | KING | United Kingdom | |
| | BEZ | Kingfisher Air Services | SEA BREEZE | United States | |
| IT | KFR | Kingfisher Airlines | KINGFISHER | India | Defunct Since 2012 IATA Code transferred to Tigerair Taiwan |
| 4I | KNX | Knighthawk Air Express | KNIGHT FLIGHT | Canada | |
| | KAS | Kingston Air Services | KINGSTON AIR | Canada | |
| | KIP | Kinnarps | KINNARPS | Sweden | |
| | KNS | Kinshasa Airways | KINSHASA AIRWAYS | Democratic Republic of the Congo | defunct |
| | KTA | Kirov Air Enterprise | VYATKA-AVIA | Russia | |
| Y9 | IRK | Kish Air | KISHAIR | Iran | |
| KR | KHA | Kitty Hawk Aircargo | AIR KITTYHAWK | United States | defunct |
| 2K | KHC | Kitty Hawk Airways | CARGO HAWK | United States | defunct |
| KP | KIA | Kiwi International Air Lines | KIWI AIR | United States | |
| | KRA | Kiwi Regional Airlines | REGIONAL | New Zealand | |
| KY | KNA | Kunming Airlines | KUNMING AIR | China | ICAO code KNA was used by Knight Air |
| | KHX | Knighthawk Express | RIZZ | United States | |
| | KGT | Knights Airlines | KNIGHT-LINER | Nigeria | |
| | KOA | Koanda Avacion | KOANDA | Spain | |
| | OYE | Koda International | KODA AIR | Nigeria | |
| 7K | KGL | Kogalymavia Air Company | KOGALYM | Russia | |
| | KOM | Kom Activity | COMJET | Netherlands | |
| | KMA | Komiaviatrans State Air Enterprise | KOMI AVIA | Russia | |
| 8J | KMV | Komiinteravia | KOMIINTER | Russia | |
| | KNM | Komsomolsk-on-Amur Air Enterprise | KNAAPO | Russia | |
| | KOB | Koob-Corp - 96 KFT | AUTOFLEX | Hungary | |
| KE | KAL | Korean Air | KOREANAIR | South Korea | |
| | KMG | Kosmas Air | KOSMAS CARGO | Serbia | |
| | KSM | Kosmos | KOSMOS | Russia | |
| | KOS | Kosova Airlines | KOSOVA | Serbia | |
| | WOK | Kovar Air | WOKAIR | Czech Republic | |
| 7B | KJC | Krasnojarsky Airlines | KRASNOJARSKY AIR | Russia | defunct |
| | KFC | Kremenchuk Flight College | KREMENCHUK | Ukraine | |
| | KRG | Krimaviamontag | AVIAMONTAG | Ukraine | |
| | KRO | Kroonk Air Agency | KROONK | Ukraine | |
| K9 | KRI | Krylo Airlines | Krylo | Russia | |
| | KYM | Krym | CRIMEA AIR | Ukraine | |
| | OPC | Krystel Air Charter | OPTIC | United Kingdom | |
| GW | KIL | Kuban Airlines | AIR KUBAN | Russia | |
| VD | KPA | Kunpeng Airlines | KUNPENG | China | |
| | KZA | Kurzemes Avio | | Russia | |
| | KBV | Kustbevakningen | SWECOAST | Sweden | |
| KU | KAC | Kuwait Airways | KUWAITI | Kuwait | |
| GO | KZU | Kuzu Airlines Cargo | KUZU CARGO | Turkey | |
| | QVR | Kvadro Aero | PEGASO | Kyrgyzstan | |
| | KWN | Kwena Air | KWENA | South Africa | |
| N5 | KGZ | Kyrgyz Airlines | BERMET | Kyrgyzstan | |
| | KTC | Kyrgyz Trans Avia | DINARA | Kyrgyzstan | |
| QH | LYN | Kyrgyzstan | ALTYN AVIA | Kyrgyzstan | Name changed to Air Kyrgyzstan |
| R8 | KGA | Kyrgyzstan Airlines | KYRGYZ | Kyrgyzstan | |
| | DAM | Kyrgyzstan Department of Aviation | FLIGHT RESCUE | Kyrgyzstan | under the Ministry of Emergency Situation |
| | KGB | Kyrgz General Aviation | KEMIN | Kyrgyzstan | |
| FK | KEW | Keewatin Air | BLIZZARD | Canada | |
| JS | KOR | Air Koryo | AIR KORYO | North Korea | |
| | AOE | Livingstone Executive | LIVINGSTONE AIR | Italy | |
| | LZF | Lease Fly | SKYLEASE | Portugal | |
| | LHB | Liebherr Geschaeftreiseflugzeug | FAMILY | Germany | |
| | LLD | Lloyd Aviation | | Venezuela | |
| | LGA | Logistic Air | LOGAIR | Malaysia | |
| | LGC | Legacy Air | LEGACY AIR | Thailand | |
| | JKA | LeTourneau University | JACKET | United States | |
| | LTY | Liberty Air | SKYDECK | Netherlands | |
| | LWL | Lowlevel | CUB DRIVER | Portugal | |
| | LAX | Laminar Air | | Spain | |
| YL | LWA | Libyan Wings | LIBYAN WINGS | Libya | |
| YQ | LCT | TAR Aerolineas | TAR | Mexico | |
| | LAH | L A Helicopter | STAR SHIP | United States | |
| | LJY | L J Aviation | ELJAY | United States | |
| | LRB | L R Airlines | LADY RACINE | Czech Republic | |
| | PHO | L&L Flygbildteknik | PHOTOFLIGHT | Sweden | |
| | LEX | L'Express Airlines | LEX | United States | |
| | FNT | L-3 Communications Flight International Aviation | FLIGHT INTERNATIONAL | United States | |
| JF | LAB | L.A.B. Flying Service | LAB | United States | |
| LR | LRC | LACSA | LACSA | Costa Rica | |
| | LDE | LADE - Líneas Aéreas Del Estado | LADE | Argentina | |
| KG | BNX | LAI - Línea Aérea IAACA | AIR BARINAS | Venezuela | |
| 4M | DSM | LATAM Argentina | LAN AR | Argentina | |
| JJ | TAM | LATAM Brasil | TAM | Brazil | |
| UC | LCO | LATAM Cargo Chile | LAN CARGO | Chile | |
| LA | LAN | LATAM Chile | LAN CHILE | Chile | |
| 4C | ARE | LATAM Colombia | LAN COLOMBIA | Colombia | |
| | LNC | LAN Dominicana | LANCANA | Dominican Republic | |
| LU | LXP | LATAM Express | LANEX | Chile | |
| PZ | LAP | LATAM Paraguay | PARAGUAYA | Paraguay | |
| LP | LPE | LATAM Peru | LANPERU | Peru | |
| NI | | LANICA | | Nicaragua | |
| | LSA | LANSA | INTERNACIONAL | Dominican Republic | |
| | APT | LAP Colombia - Líneas Aéreas Petroleras, S.A. | LAP | Colombia | |
| | LCB | LC Busre | BUSRE | Peru | |
| L5 | | Línea Aérea Cuencana | | Ecuador | |
| LO | LOT | LOT Polish Airlines | POLLOT | Poland | "POLLOT" is not used in practice. "LOT" is used in almost all cases. |
| | JKA | LeTourneau University | JACKET | United States | |
| XO | LTE | LTE International Airways | FUN JET | Spain | |
| L3 | LTO | LTU Austria | BILLA TRANSPORT | Austria | |
| LT | LTU | LTU International | LTU | Germany | |
| | JFC | LTV Jet Fleet Corporation | JET-FLEET | United States | |
| | LUK | LUKoil-Avia | LUKOIL | Russia | |
| | ASK | La Ronge Aviation Services | AIR SASK | Canada | |
| | LVT | La Valenciana Taxi Aéreo | TAXIVALENCIANA | Mexico | |
| | SKQ | Labcorp | SKYLAB | United States | |
| | LAL | Labrador Airways | LAB AIR | Canada | |
| N6 | JEV | Lagun Air | | Spain | |
| | HCA | Lake Havasu Air Service | HAVASU | United States | |
| | LKL | Lakeland Aviation | LAKELAND | United States | |
| | LKR | Laker Airways | LAKER | United States | |
| | LBH | Laker Airways (Bahamas) | LAKER BAHAMAS | United States | |
| | LMR | Lamra | LAMAIR | Sudan | |
| | TCR | Lanaes Aereas Trans Costa Rica | TICOS | Costa Rica | |
| | ISL | Landsflug | ISLANDIA | Iceland | |
| | PAP | Langtry Flying Group | PROFLIGHT | United Kingdom | |
| IK | LKN | Lankair | Lankair | Sri Lanka | |
| QL | RLN | Lankan Cargo | AERO LANKA | Sri Lanka | |
| | LZA | Lanza Air | AEROLANZA | Spain | |
| | LZT | Lanzarote Aerocargo | BARAKA | Spain | |
| QV | LAO | Lao Airlines | LAO | Lao People's Democratic Republic | |
| | LKA | Lao Capricorn Air | NAKLAO | Lao People's Democratic Republic | |
| | LLL | Lao Skyway | LAVIE | Lao People's Democratic Republic | |
| L7 | LPN | Laoag International Airlines | LAOAG AIR | Philippines | |
| | LRD | Laredo Air | LAREDO AIR | United States | |
| | OTN | LASTP | LASTP | São Tomé and Príncipe | |
| | LTC | LatCharter | LATCHARTER | Latvia | defunct |
| | LAF | Latvian Air Force | LATVIAN AIRFORCE | Latvia | |
| NG | LDA | Lauda Air | LAUDA AIR | Austria | |
| OE | LDM | LaudaMotion | LAUDA MOTION | Austria | |
| | LDI | Lauda Air Italy | LAUDA ITALY | Italy | |
| | LEP | Laughlin Express | LAUGHLIN EXPRESS | United States | |
| | LSU | Laus | LAUS AIR | Croatia | |
| | LAR | Lawrence Aviation | LAWRENCE | United States | |
| | LAY | Layang-Layang Aerospace | LAYANG | Malaysia | |
| | LPL | Lease-a-Plane International | LEASE-A-PLANE | United States | |
| LQ | LAQ | Lebanese Air Transport | LAT | Lebanon | |
| | LAT | Lebanese Air Transport (charter) | LEBANESE AIR | Lebanon | |
| | LAD | Lebanon Airport Development Corporation | LADCO-AIR | United States | |
| | LEB | Lebap | LEBAP | Turkmenistan | |
| | LCA | Leconte Airlines | LECONTE | United States | |
| LI | LIA | Leeward Islands Air Transport | LIAT | Antigua and Barbuda | |
| | LGD | Legend Airlines | LEGENDARY | United States | |
| | LWD | Leisure Air | LEISURE WORLD | United States | |
| | LEN | Lentini Aviation | LENTINI | United States | |
| | LOR | Leo-Air | LEO CHARTER | South Africa | |
| | LEL | Leonsa De Aviación | LEONAVIA | Spain | |
| LL | LVL | Level | LEVEL | Spain | |
| | LYW | Libyan Airlines | LIBYAN AIRWAYS | Libya | |
| LN | LAA | Libyan Arab Airlines | LIBAIR | Libya | |
| | LCR | Libyan Arab Air Cargo | LIBAC | Libya | |
| | LIQ | Lid Air | | Sweden | |
| | LTA | LIFT Academy | LIFT | United States | |
| | LCG | Lignes Aeriennes Congolaises | CONGOLAISE | Democratic Republic of the Congo | |
| | LKD | Lignes Aeriennes Du Tchad | LATCHAD | Chad | |
| | LME | Lignes Mauritaniennes Air Express | LIMAIR EXPRESS | Mauritania | |
| | GCB | Lignes Nationales Aeriennes - Linacongo | LINACONGO | Republic of the Congo | |
| | GDQ | Lincoln Air National Guard | | United States | |
| | LRT | Lincoln Airlines | | Australia | |
| | LSY | Lindsay Aviation | LINDSAY AIR | United States | |
| | NOT | Línea Aérea Costa Norte | COSTA NORTE | Chile | |
| | LMC | Línea Aérea Mexicana de Carga | LINEAS DECARGA | Mexico | |
| L7 | LNP | Línea Aérea SAPSA | SAPSA | Chile | |
| | NEG | Línea Aérea de Fumig Aguas Negras | AGUAS NEGRAS | Chile | |
| QL | LER | Línea Aérea de Servicio Ejecutivo Regional | LASER | Venezuela | |
| | LSE | Línea De Aeroservicios | | Chile | |
| | TUY | Línea Turística Aereotuy | AEREOTUY | Venezuela | |
| | ALR | Líneas Aéreas Alaire S.L. | AEROLAIRE | Spain | |
| ZE | LCD | Líneas Aéreas Azteca | LINEAS AZTECA | Mexico | defunct |
| | LCN | Líneas Aéreas Canedo LAC | CANEDO | Bolivia | |
| | LCM | Líneas Aéreas Comerciales | LINEAS COMERCIALES | Mexico | |
| | EDD | Líneas Aéreas Ejectuivas De Durango | LINEAS DURANGO | Mexico | |
| | EDR | Líneas Aéreas Eldorado | ELDORADRO | Colombia | |
| | FED | Líneas Aéreas Federales | FEDERALES | Argentina | |
| | LMN | Líneas Aéreas Monarca | LINEAS MONARCA | Mexico | |
| | LIJ | Líneas Aéreas San Jose | LINEAS JOSE | Mexico | |
| | UMA | Líneas Aéreas del Humaya | HUMAYA | Mexico | |
| | LEC | Linex | LECA | Central African Republic | |
| | SMS | Linhas Aéreas Santomenses | SANTOMENSES | São Tomé and Príncipe | |
| TM | LAM | Linhas Aéreas de Moçambique | MOZAMBIQUE | Mozambique | |
| | LAW | Link Airways of Australia | | Australia | |
| | WGT | Volkswagen AirService GmbH | WORLDGATE | United Kingdom | |
| JT | LNI | Lion Air | LION INTER | Indonesia | |
| | LEU | Lions-Air | LIONSAIR | Switzerland | |
| | LYF | Lithuanian Air Force | LITHUANIAN AIRFORCE | Lithuania | safety department |
| | LRA | Little Red Air Service | LITTLE RED | Canada | |
| LM | LVG | Livingston Energy Flight | LIVINGSTON | Italy | Ceased operations 2010 |
| LT | SNG | LJ Air | SNOW EAGLE | China | |
| LB | LLB | Lloyd Aéreo Boliviano | LLOYDAEREO | Bolivia | |
| | LNA | Lnair Air Services | ELNAIR | Spain | |
| | XLG | Lockheed Air Terminal | | United States | |
| | LAC | Lockeed Aircraft Corporation | LOCKHEED | United States | |
| | XDD | Lockheed DUATS | | United States | |
| | CBD | Lockheed Martin Aeronautics | CATBIRD | United States | |
| | LNG | Lockheed Martin Aeronautics Company | LIGHTNING | United States | |
| LM | LOG | Loganair | LOGAN | United Kingdom | Gained the code LM after beginning independent operations (2017) |
| | CLV | Lom Praha Flying School | AEROTRAINING | Czech Republic | |
| | LMS | Lomas Helicopters | LOMAS | United Kingdom | |
| | LCY | London City Airport Jet Centre | LONDON CITY | United Kingdom | |
| | LNX | London Executive Aviation | LONEX | United Kingdom | |
| | LOV | London Flight Centre (Stansted) | LOVEAIR | United Kingdom | |
| | LHC | London Helicopter Centres | MUSTANG | United Kingdom | |
| | LSS | Lone Star Airlines | LONE STAR | United States | |
| | ORA | Long Island Airlines | LONG ISLAND | United States | |
| GI | LHA | Longhao Airlines | AIR CANTON | China | |
| | LGT | Longtail Aviation | LONGTAIL | Bermuda | |
| GJ | CDC | Loong Air | LOONG AIR | China | |
| | LRR | Lorraine Aviation | LORRAINE | France | |
| | LSC | Los Cedros Aviación | CEDROS | Chile | |
| | TAS | Lotus Air | LOTUS FLOWER | Egypt | |
| | LTW | Luchtvaartmaatschappij Twente | TWENTAIR | Netherlands | |
| | LKE | Lucky Air | LUCKY AIR | China | |
| | LUT | Luft Carago | LUGO | South Africa | |
| | LVD | Luftfahrt-Vermietungs-Dienst | AIR SANTE | Austria | |
| LH | DLH | Lufthansa | LUFTHANSA | Germany | |
| LH | GEC | Lufthansa Cargo | LUFTHANSA CARGO | Germany | |
| CL | CLH | Lufthansa CityLine | HANSALINE | Germany | |
| L1 | | Lufthansa Systems | | Germany | |
| | LHT | Lufthansa Technik | LUFTHANSA TECHNIK | Germany | |
| | LTF | Lufttaxi Fluggesellschaft | Garfield | Germany | |
| L5 | LTR | Lufttransport | LUFT TRANSPORT | Norway | |
| | LHS | Luhansk | ENTERPRISE LUHANSK | Ukraine | |
| | UNY | Lund University School of Aviation | UNIVERSITY | Sweden | |
| LG | LGL | Luxair | LUXAIR | Luxembourg | |
| | LXA | Luxaviation | RED LION | Luxembourg | |
| | LUV | Luxembourg Air Rescue | LUX RESCUE | Luxembourg | |
| | LFE | Luxflight Executive | LUX EXPRESS | Luxembourg | |
| | LXO | Luxor Air | | Egypt | |
| | LUZ | Luzair | LISBON JET | Portugal | |
| 5V | UKW | Lviv Airlines | UKRAINE WEST | Ukraine | |
| | LYD | Lydd Air | LYDDAIR | United Kingdom | |
| | LCH | Lynch Flying Service | LYNCH AIR | United States | |
| L2 | LYC | Lynden Air Cargo | LYNDEN | United States | |
| | LWG | Luxwing | LUXWING | Malta | |
| Y9 | DAT | Lynx Air | DAUNTLESS | Canada | |
| | LXF | Lynx Air International | LYNX FLIGHT | United States | |
| L4 | SSX | Lynx Aviation | SHASTA | United States | Part of Frontier Airlines |
| | LYX | Lynx Aviation | LYNX AIR | Pakistan | |
| Z8 | AZN | Línea Aérea Amaszonas | | Bolivia | |
| MJ | LPR | Líneas Aéreas Privadas Argentinas | LAPA | Argentina | defunct |
| | LAU | Líneas Aéreas Suramericanas | SURAMERICANO | Colombia | |
| LT | SNG | LongJiang Airlines | SNOW EAGLE | China | |
| | LYB | Lynden Air Cargo | HIGHLANDS | Papua New Guinea | |
| Q2 | DQA | Maldivian (airline) | SKYSURFER | Maldives | |
| | MMH | McMahon Helicopter | NIGHT RIDER | United States | 2015 |
| | HOG | Mahogany Air Charters | HOGAN AIR | Zambia | 2014 |
| | MTS | Med Jets | MED SERVICE | Mexico | 2014 |
| | MSF | Minsheng International Jet | MEINSHENG | China | 2014 |
| | MXS | Millon Express | MILLON EXPRESS | United States | Trading name for Sunrise Airlines allocated in 2014 |
| | MHF | Maritime Helicopters | AIR MARITIME | United States | Allocated 2014 |
| BF | MRK | MarkAir | MARKAIR | United States | 1984-1995 |
| WD | MWM | Modern Transporte Aereo De Carga | MODERNAIR | Brazil | |
| | MSJ | Magnum Air | MAGNUM AIR | Philippines | |
| | MWI | Malawian Airlines 2014 | MALAWIAN | Malawi | |
| | MYP | Mann Yadanarpon Airlines | MANN ROYAL | Myanmar | |
| | RDK | Memorial Hermann Hospital System | RED DUKE | United States | Houston, Texas |
| | MLV | Multiservicios Aereos Del Valle | MULTI VALLE | Mexico | |
| | MMJ | Macau Jet International | MACAUJET | China | |
| | MXF | Maximum Flight Advantages | MAXFLIGHT | United States | |
| OD | MXD | Malindo Airways | MALINDO EXPRESS | Malaysia | |
| | MJC | Mandarin Air | AIR MANDA | China | |
| | PLG | MBK-S | PILGRIM | Russia | |
| | DZR | Midwest Aviation | DOZER | United States | |
| | MSN | Milenium Air Servicios Aereos Integrados | | Mexico | |
| | MFB | Mountain Flyers 80 | MOUNTAINHELI | Switzerland | |
| | HTL | My Fair Jet | HOTLINE | Austria | |
| | JNH | M & N Aviation | JONAH | United States | |
| | MCF | MAC Fotografica | MAC FOTO | Spain | |
| | MRG | MANAG'AIR | MANAG'AIR | France | |
| AQ | MPJ | MAP-Management and Planung | MAPJET | Austria | |
| | TFG | MAS Airways | TRAFALGAR | United Kingdom | |
| M7 | MAA | MasAir | MAS CARGA | Mexico | |
| MY | MWG | MASwings | MASWINGS | Malaysia | |
| IN | MAK | MAT Macedonian Airlines | MAKAVIO | Macedonia | Defunct |
| | MCC | MCC Aviation | DISCOVERY | South Africa | |
| | MGA | MG Aviación | MAG AVACION | Spain | |
| | JLA | MIA Airlines | SALLINE | Romania | |
| OM | MGL | MIAT Mongolian Airlines | MONGOL AIR | Mongolia | |
| | MNC | MIT Airlines | MUNCIE | Canada | |
| | MKA | MK Airline | KRUGER-AIR | Ghana | |
| MB | MNB | MNG Airlines | BLACK SEA | Turkey | |
| | EBF | MSR Flug-Charter | SKYRUNNER | Germany | |
| | MCV | MTC Aviación | MTC AVIACION | Mexico | |
| | MAQ | Mac Aviation | MAC AVIATION | Spain | |
| | MCN | Mac Dan Aviation Corporation | MAC DAN | United States | |
| | MTD | MacKnight Airlines | | Australia | |
| CC | MCK | Macair Airlines | | Australia | |
| | MCS | Macedonian Airlines | MACAIR | Greece | |
| | MDH | Madina Air | MADINA AIR | Libya | |
| DM | DAN | Maersk Air | MAERSKAIR | Denmark | Defunct |
| VB | MSK | Maersk Air UK | BLUESTAR | United Kingdom | Defunct, later became Duo Airways |
| | MJB | Magic Blue Airlines | MAGIC BLUE | Netherlands | |
| | MGR | Magna Air | MAGNA AIR | Austria | |
| | MLH | Mahalo Air | MAHALO | United States | |
| W5 | IRM | Mahan Air | MAHAN AIR | Iran | |
| M2 | MZS | Mahfooz Aviation | MAHFOOZ | Gambia | |
| | MAT | Maine Aviation | MAINE-AV | United States | |
| | MAJ | Majestic Airlines | MAGIC AIR | United States | |
| | AKM | Mak Air | MAKAIR | Kazakhstan | |
| | MLG | Malagasy Airlines | | Madagascar | |
| | MLX | Malawi Express | MALAWI EXPRESS | Malawi | |
| | MKK | Malaya Aviatsia Dona | AEROKEY | Russia | |
| MH | MAS | Malaysia Airlines | MALAYSIAN | Malaysia | |
| DB | MLT | Maleth-Aero | | Malta | |
| | MAE | Mali Air | MALI AIREXPRESS | Austria | |
| | VXP | Mali Air Express | AVION EXPRESS | Mali | |
| | MTZ | Mali Airways | MALI AIRWAYS | Mali | |
| | MLC | Malila Airlift | MALILA | Democratic Republic of the Congo | |
| | MLS | Mall Airways | MALL-AIRWAYS | United States | |
| | LOD | Malmoe Air Taxi | LOGIC | Sweden | |
| TF | SCW | Malmö Aviation | SCANWING | Sweden | |
| | MAY | Malta Air | | Malta | 2019 |
| R5 | MAC | Malta Air Charter | MALTA CHARTER | Malta | Defunct? |
| | MWS | Malta Wings | MALTA WINGS | Malta | |
| MA | MAH | Malév Hungarian Airlines | MALEV | Hungary | defunct |
| | MLB | Manaf International Airways | MANAF | Burundi | |
| RI | MDL | Mandala Airlines | MANDALA | Indonesia | |
| AE | MDA | Mandarin Airlines | MANDARIN | Taiwan | |
| JE | MNO | Mango | TULCA | South Africa | |
| | MHN | Manhattan Air | MANHATTAN | United Kingdom | |
| | MTO | Marathon Airlines | MARATHON | Greece | |
| | MNR | Mann Air | TEEMOL | United Kingdom | |
| | MAN | Mannion Air Charter | MANNION | United States | |
| | MTS | Mantrust Asahi Airways | MANTRUST | Indonesia | |
| | MNX | Manx Airlines | MANX | United Kingdom | |
| | MAD | Maple Air Services | MAPLE AIR | Canada | |
| | MAR | March Helicopters | MARCH | United Kingdom | |
| | MCP | Marcopolo Airways | MARCOPOLO | Afghanistan | |
| | MGI | Marghi Air | MARGHI | Nigeria | |
| | MRK | Markair | MARKAIR | United States | |
| | MKO | Markoss Aviation | GOSHAWK | United Kingdom | |
| 6V | MRW | Mars RK | AVIAMARS | Ukraine | |
| | MCE | Marshall Aerospace | MARSHALL | United Kingdom | |
| M7 | MSL | Marsland Aviation | MARSLANDAIR | Sudan | |
| | XMA | Martin Aviation Services | | United States | |
| | MBE | Martin-Baker | MARTIN | United Kingdom | |
| MP | MPH | Martinair | MARTINAIR | Netherlands | |
| | MRA | Martinaire | MARTEX | United States | |
| | MFA | Martyn Fiddler Associates | SEAHORSE | United Kingdom | |
| | MVN | Marvin Limited | MARVIN | United Kingdom | |
| | TRP | Maryland State Police | TROOPER | United States | |
| | MTH | Massachusetts Institute of Technology | RESEARCH | United States | |
| | MSY | Massey University School of Aviation | MASSEY | New Zealand | |
| | MSW | Master Airways | MASTER AIRWAYS | Serbia | |
| | MPL | Master Planner | | United States | |
| | LMJ | Masterjet | MASTERJET | Portugal | |
| Q4 | | Mastertop Linhas Aéreas | | Brazil | |
| | MIA | Mauria | MAURIA | Mauritania | |
| | MNV | Mauritanienne Aerienne Et Navale | NAVALE | Mauritania | |
| | MRF | Mauritanienne Air Fret | MAUR-FRET | Mauritania | |
| | MWY | Mauritanienne Airways | MAURITANIENNE | Mauritania | |
| | MDE | Mauritanienne De Transport Aerien | MAURI-TRANS | Mauritania | |
| | MVR | Maverick Airways | MAV-AIR | United States | |
| H5 | MVL | Mavial Magadan Airlines | Mavial | Russia | |
| | MAI | Max Avia | MAX AVIA | Kyrgyzstan | |
| | MSF | Max Sea Food | MAXESA | El Salvador | |
| | MAX | Max-Aviation | MAX AVIATION | Canada | |
| 8M | MXL | Maxair | MAXAIR | Sweden | |
| | MXU | Maximus Air Cargo | CARGO MAX | United Arab Emirates | |
| MY | MXJ | Maxjet Airways | MAX-JET | United States | Defunct |
| | MXS | Maxsus-Avia | MAXSUS-AVIA | Uzbekistan | |
| | MXP | May Air Xpress | BEECHNUT | United States | |
| MW | MYD | Maya Island Air | MYLAND | Belize | |
| 7M | MYI | Mayair | MAYAIR | Mexico | |
| | MBS | Mbach Air | MBACHI AIR | Malawi | Ground Services |
| | MCH | McAlpine Helicopters | MACLINE | United Kingdom | |
| | MKL | McCall Aviation | MCCALL | United States | |
| | DAC | McDonnell Douglas | DACO | United States | |
| | MDS | McNeely Charter Services | MID-SOUTH | United States | |
| | MEK | Med-Trans of Florida | MED-TRANS | United States | |
| | MDM | Medavia | MEDAVIA | Malta | |
| | MRZ | Medical Air Rescue Services | MARS | Zimbabwe | |
| | MCL | Medical Aviation Services | MEDIC | United Kingdom | |
| | MDF | Mediterranean Air Freight | MED-FREIGHT | Greece | |
| | MDY | Mediterranean Airways | | Egypt | |
| | MEJ | Medjet International | MEDJET | United States | |
| | MGK | Mega | MEGLA | Kazakhstan | |
| | MEL | Mega Linhas Aéreas | MEGA AIR | Brazil | |
| M8 | MKN | Mekong Airlines | MEKONG AIRLINES | Cambodia | Defunct |
| IM | MNJ | Menajet | MENAJET | Lebanon | |
| | | Mercer Airlines | | United States | Defunct |
| | MXX | Merchant Express Aviation | MERCHANT | Nigeria | |
| | MEC | Mercury Aircourier Service | MERCAIR | United States | |
| | POV | Meridian | AIR POLTAVA | Ukraine | |
| | MRD | Meridian Air Cargo | MERIDIAN | United States | |
| | MHL | Meridian Airlines | HASSIMAIR | Nigeria | |
| | DSL | Meridian Aviation | DIESEL | United Kingdom | |
| | MEM | Meridian Limited | MERIDIAN CHERRY | Ukraine | |
| IG | ISS | Meridiana | MERIDIANA | Italy | Callsign was MERAIR |
| | MEI | Merlin Airways | AVALON | United States | |
| MZ | MNA | Merpati Nusantara Airlines | MERPATI | Indonesia | |
| YV | ASH | Mesa Airlines | AIR SHUTTLE | United States | |
| XJ | MES | Mesaba Airlines | MESABA | United States | |
| | MSQ | Meta Linhas Aéreas | META | Brazil | |
| | MET | Meteorological Research Flight | METMAN | United Kingdom | METMAN1 callsign currently used by FAAM Airborne Laboratory, operated by Airtask Group |
| | MER | Methow Aviation | METHOW | United States | |
| | MVI | Metro Business Aviation | | United Kingdom | |
| | MEX | Metro Express | EAGLE EXPRESS | United States | |
| | MTR | Metroflight | METRO | United States | |
| | MTJ | Metrojet | METROJET | Hong Kong | |
| | PIX | Metropix UK | METROPIX | United Kingdom | |
| | MPS | Metropolis | METRO REGIONAL | Netherlands | Metropolis Noord 1 |
| | MXB | Mex Blue | MEX BLUE | Mexico | |
| | MJT | Mex-Jet | MEJETS | Mexico | |
| GJ | MXC | Mexicargo | MEXICARGO | Mexico | defunct |
| | MXA | Mexicana de Aviación | MEXICANA | Mexico | |
| | MXT | México Transportes Aéreos | TRANSMEX | Mexico | |
| | HUR | Miami Air Charter | HURRICANE CHARTER | United States | |
| LL | BSK | Miami Air International | BISCAYNE | United States | Previous IATA Code "GL" |
| | OWL | Miami Valley Aviation | NIGHT OWL | United States | |
| | MPT | Miapet-Avia | MIAPET | Armenia | |
| | BIB | Michelin Air Services | | France | |
| | WIZ | Micromatter Technology Solutions | WIZARD | United Kingdom | |
| | NYL | Mid Airlines | NILE | Sudan | |
| | MPA | Mid-Pacific Airlines | MID PAC | United States | |
| | MJR | Midamerica Jet | MAJOR | United States | |
| ME | MEA | Middle East Airlines | CEDAR JET | Lebanon | |
| | MID | Midland Airport Services | | United Kingdom | |
| | MFR | Midline Air Freight | MIDLINE FREIGHT | United States | |
| | MIS | Midstate Airlines | MIDSTATE | United States | |
| JI | MDW | Midway Airlines (1993–2003) | MIDWAY | United States | defunct |
| ML | MDW | Midway Airlines (1976–1991) | MIDWAY | United States | defunct |
| | FLA | Midway Express | PALM | United States | |
| | FAX | Midwest Air Freighters | FAIRFAX | United States | |
| YX | MEP | Midwest Airlines | MIDEX | United States | |
| MY | MWA | Midwest Airlines (Egypt) | | Egypt | |
| | NIT | Midwest Aviation | NIGHTTRAIN | United States | |
| | MWT | Midwest Aviation Division | MIDWEST | United States | |
| | HTE | Midwest Helicopters De Mexico | HELICOPTERSMEXICO | Mexico | |
| MJ | MLR | Mihin Lanka | MIHIN LANKA | Sri Lanka | |
| | MAB | Millardair | MILLARDAIR | Canada | |
| | RJM | Millen Corporation | MILLEN | United Kingdom | |
| | MLK | Millennium Air | NIGERJET | Nigeria | |
| | DLK | Millennium Airlines | DEKKANLANKA | Sri Lanka | |
| | MFS | Miller Flying Services | MILLER TIME | United States | |
| | OXO | Million Air | MILL AIR | United States | |
| | MIM | Mimino | MIMINO | Russia | |
| | NAB | Mina Airline Company | | Egypt | |
| | OMR | Minair | ORMINE | Central African Republic | |
| | EBE | Minebea Technologies | MINEBEA | United States | |
| | MAZ | Mines Air Services Zambia | MINES | Zambia | |
| | MNL | Miniliner | MINILINER | Italy | |
| | MNS | Ministic Air | MINISTIC | Canada | |
| | WDG | Ministry of Agriculture, Fisheries and Food | WATCHDOG | United Kingdom | |
| | LIR | Minsk Aircraft Overhaul Plant | LISLINE | Belarus | |
| | MIC | Mint Airways | MINT AIRWAYS | Spain | |
| | MIR | Miramichi Air Service | MIRAMICHI | Canada | |
| | MIF | Miras | MIRAS | Kazakhstan | |
| | MOS | Misr Overseas Airways | | Egypt | |
| | MAF | Mission Aviation Fellowship | MISSI | Indonesia | |
| | MSN | Missionair | MISIONAIR | Spain | |
| | MRN | Missions Gouvernemtales Francaises | MARIANNE | France | |
| | BDG | Mississippi State University | BULLDOG | United States | |
| XV | MVA | Mississippi Valley Airlines | VALAIR | United States | |
| M4 | MSA | Mistral Air | AIRMERCI | Italy | renamed Poste Air Cargo |
| | MJF | MJET | EM-EXPRESS | Austria | |
| | MBO | Mobil Oil | MOBIL | Canada | |
| | MXE | Mocambique Expresso | MOZAMBIQUE EXPRESS | Mozambique | |
| | MFZ | Mofaz Air | MOFAZ AIR | Malaysia | |
| | MOW | Mohawk Airlines | MOHAWK AIR | United States | |
| MW | MUL | Mokulele Airlines | MUKULELE | United States | Callsign and code changed from BUG/SPEEDBUGGY in 2013 |
| | MLE | Moldaeroservice | MOLDAERO | Moldova | |
| 2M | MDV | Moldavian Airlines | MOLDAVIAN | Moldova | |
| | MVG | Moldova | MOLDOVA-STATE | Moldova | |
| | RRV | Mombasa Air Safari | SKYROVER | Kenya | |
| ZB | MON | Monarch Airlines | MONARCH | United Kingdom | defunct October 2017 |
| | MNH | Monarch Airlines | MONARCH AIR | United States | |
| 8I | | Myway Airlines | | Italy | |
| | MFC | Moncton Flying Club | EAST WIND | Canada | |
| | MDB | Monde Air Charters | MONDEAIR CARGO | United Kingdom | |
| | MTI | Monerrey Air Taxi | MONTERREY AIR | Mexico | |
| | MKY | Monky Aerotaxis | MONKY | Mexico | |
| YM | MGX | Montenegro Airlines | MONTENEGRO | Montenegro | former callsign was "MONTAIR" |
| 5M | MNT | Montserrat Airways | MONTSERRAT | Montserrat | |
| | MNY | Mooney Aircraft Corporation | MOONEY FLIGHT | United States | |
| | MAL | Morningstar Air Express | MORNINGSTAR | Canada | |
| | MSS | Morris Air Service | WASATCH | United States | |
| | MRO | Morrison Flying Service | MORRISON | United States | |
| 3R | GAI | Moskovia Airlines | GROMOV AIRLINE | Russia | JSC |
| | MPI | Mosphil Aero | MOSPHIL | Philippines | |
| M9 | MSI | Motor Sich Airlines | MOTOR SICH | Ukraine | |
| NM | NZM | Mount Cook Airline | MOUNTCOOK | New Zealand | |
| | MTN | Mountain Air Cargo | MOUNTAIN | United States | |
| N4 | MTC | Mountain Air Company | MOUNTAIN LEONE | Sierra Leone | |
| | PKP | Mountain Air Express | PIKES PEAK | United States | |
| | BRR | Mountain Air Service | MOUNTAIN AIR | United States | |
| | MBI | Mountain Bird | MOUNTAIN BIRD | United States | |
| | MHA | Mountain High Aviation | MOUNTAIN HIGH | United States | |
| | MPC | Mountain Pacific Air | MOUNTAIN PACIFIC | Canada | |
| | MTV | Mountain Valley Air Service | MOUNTAIN VALLEY | United States | |
| | MDN | Mudan Airlines | | Somali Republic | |
| | CMJ | Mudanjiang General Aviation | MUDANJIANG | China | |
| | MTX | Multi Taxi | MULTITAXI | Mexico | |
| | WBR | Multi-Aero | WEBER | United States | |
| | MFT | Multiflight | YORKAIR | | |
| | MNZ | Murmansk Aircompany | MURMAN AIR | Russia | |
| | MUA | Murray Air | MURRAY AIR | United States | |
| | MMR | Musrata Air Transport | MUSRATA AIR | Libya | |
| | MAW | Mustique Airways | MUSTIQUE | Barbados | |
| Z9 | MYM | MYAirline | MYAIR | Malaysia | defunct |
| | MYW | MyWay Airlines | MYSKY | Georgia | |
| VZ | MYT | MyTravel Airways | KESTREL | United Kingdom | Defunct, callsign now used by Thomas Cook Airlines |
| UB | UBA | Myanma Airways | UNIONAIR | Myanmar | |
| 8M | MMA | Myanmar Airways International | MYANMAR | Myanmar | |
| | MAV | Minoan Air | MINOAN | Greece | |
| | MYA | Myflug | MYFLUG | Iceland | |
| | VKG | MyTravel Airways | VIKING | Denmark | defunct; callsign now used by Thomas Cook Airlines Scandinavia |
| | AAD | Mann Air Ltd | Ambassador | United Kingdom | t/a Ambassador |
| M2 | MHV | MHS Aviation GmbH | SNOWCAP | Germany | |
| | MTU | Middle Tennessee State University | BLUE RAIDER | United States | 2019 |
| NP | NIA | Nile Air | NILE BIRD | Egypt | |
| | SIQ | National Center for Atmospheric Research | SCIENCE QUEST | United States | |
| | NEJ | Netjets Business Aviation | NET BUSINESS | China | |
| | NHV | NHV Aviation | | Ghana | |
| | NHC | Northern Helicopter | NORTHERN | Germany | |
| | DMD | Namdeb Diamond Corporation | DIAMONDJET | Namibia | |
| 6N | NIN | Niger Airlines | NIGER AIRLINES | Niger | |
| N5 | FEY | Fly Easy | FLYEASY | India | |
| | NUB | Nomad Aviation | VALLETTA | Malta | |
| | NJA | New Japan Aviation | SHIN NIHON | Japan | |
| | ROW | Nor Aviation | ROTORWING | Norway | |
| | NLG | NEL Cargo | NELCARGO | Ivory Coast | |
| | NHG | NHT Linhas Aéreas | HELGA | Brazil | |
| | WAR | NZ Warbirds Association | WARBIRDS | New Zealand | |
| | ANL | Nacoia Lda | AIR NACOIA | Angola | |
| | NHZ | Nada Air Service | NADA AIR | Chad | |
| | BFN | Compangnie Nationale Naganagani | | Burkina Faso | |
| | NAH | Nahanni Air Services Ltd | NAHANNI | Canada | |
| | NKL | Nakheel Aviation | NAKHEEL | United Arab Emirates | |
| | MRE | Namibia Commercial Aviation | MED RESCUE | Namibia | |
| | NDF | Namibian Defence Force | NAMIBIAN AIR FORCE | Namibia | |
| | CNJ | Nanjing Airlines | NINGHANG | China | |
| DV | ACK | Nantucket Airlines | ACK AIR | United States | WAS 9k |
| | NYA | Nanyah Aviation | NANYAH | Israel | |
| | NAP | Napier Air Service Inc | NAPIER | United States | |
| | NCM | Nas Air | AIR BANE | Angola | |
| P9 | | Nas Air | | Mali | |
| UE | NAS | Nasair | NASAIRWAYS | Eritrea | |
| | NJC | Nashville Jet Charters | NASHVILLE JET | United States | |
| | NCO | Natalco Air Lines | NATALCO | São Tomé and Príncipe | |
| | NTK | National Air Traffic Controllers Association | NATCA | United States | |
| | NSR | National Air Charter | NASAIR | Indonesia | |
| | RFI | National Air Traffic Services | SHERLOCK | United Kingdom | |
| | NAN | National Airlines | NATION AIR | United States | defunct |
| N4 | NCN | National Airlines | | Chile | |
| N7 | ROK | National Airlines | RED ROCK | United States | defunct |
| NA | NAL | National Airlines | NATIONAL | United States | defunct |
| N8 | NCR | National Air Cargo dba National Airlines | NATIONAL CARGO | United States | |
| 9Y | NAE | National Airways Ethiopia | NATIONAL | Ethiopia | |
| IN | NIH | NAM Air | NAM | Indonesia | |
| | KUS | National Airlines | KUSWAG | South Africa | |
| 9O | | National Airways Cameroon | | Cameroon | |
| | LFI | National Airways Corporation | AEROMED | South Africa | |
| | GTY | National Aviation Company | | Egypt | |
| | TNC | National Aviation Consultants | NATCOM | Canada | |
| | NXT | National Express | NATIONAL FREIGHT | United States | Texas Air Charters |
| | GRD | National Grid plc | GRID | United Kingdom | |
| NC* | JTE | National Jet Express | JETEX | Australia | |
| | AND | National Jet Service | AIR INDIANA | United States | |
| NC* | NJS | National Jet Systems | NATIONAL JET | Australia | defunct acquired by Qantas |
| | NOL | National Overseas Airlines Company | NAT AIRLINE | Egypt | |
| | NLS | Nationale Luchtvaartschool | PANDER | Netherlands | |
| | NAE | Nations Air Express Inc | NATIONS EXPRESS | United States | |
| CE | NTW | Nationwide Airlines | NATIONWIDE | South Africa | |
| | NWZ | Nationwide Airlines (Zambia) | ZAMNAT | Zambia | |
| | EVM | Natural Environment Research Council | SCIENCE | United Kingdom | |
| | NRR | Natureair | NATUREAIR | Costa Rica | |
| | NRK | Naturelink Charter | NATURELINK | South Africa | |
| | NVC | Nav Canada | NAV CAN | Canada | |
| | NAV | Nav Flight Planning | NAV DISPATCH | Czech Republic | |
| | NVP | Navegacao Aérea De Portugal | | Portugal | |
| | NAY | Navegación Servicios Aéreos Canarios S.A. | NAYSA | Spain | |
| | IRI | Navid | NAVID | Iran | |
| | NVM | Naviera Mexicana | NAVIERA | Mexico | |
| | NVL | Navigator Airlines | NAVLINES | Armenia | |
| | XNV | Navinc Airlines Services | | United States | Tigin Limited |
| 1N | | Navitaire | | United States | |
| | XNS | Navtech System Support | | Canada | |
| | NZA | Nayzak Air Transport | | Libya | |
| | NEB | State of Nebraska | NEBRASKA | United States | |
| | NEC | Necon Air | NECON AIR | Nepal | |
| | NCG | Nederlandse Kustwacht | NETHERLANDS COASTGUARD | Netherlands | |
| | NFT | Nefteyugansk Aviation Division | NEFTEAVIA | Russia | |
| | NLA | Neiltown Air | NEILTOWN AIR | Canada | |
| | NLC | Nelair Charters | NELAIR | South Africa | |
| | CGE | Nelson Aviation College | COLLEGE | New Zealand | |
| RA | RNA | Nepal Airlines | ROYAL NEPAL | Nepal | was Royal Nepal Airlines |
| NO | NOS | Neos | MOONFLOWER | Italy | |
| | TOX | Neosiam Airways | SKY KINGDOM | Thailand | |
| | NSL | Neric | NERICAIR | United Kingdom | |
| NE | NMA | Nesma Airlines | NESMA | Egypt | |
| 1I | EJA | NetJets | EXECJET | United States | |
| | NET | Network Aviation Services | NETWORK | Nigeria | |
| | NEZ | New England Air Express | ENGAIR | United States | |
| EJ | NEA | New England Airlines | NEW ENGLAND | United States | |
| | NHT | New Heights 291 | NEWHEIGHTS | South Africa | |
| | NWD | New World Jet Corporation | NEW WORLD | United States | |
| | NYH | New York Helicopter | NEW YORK | United States | |
| | GRY | New York State Police | GRAY RIDER | United States | |
| | KRC | Royal New Zealand Air Force | KIWI RESCUE | New Zealand | |
| | HVA | Newair | HAVEN-AIR | United States | |
| | NLT | Newfoundland Labrador Air Transport | NALAIR | Canada | |
| 2N | NTJ | NextJet | NEXTJET | Sweden | |
| | NXF | Nextflight Aviation | NEXTFLIGHT | United States | |
| | NXS | Nexus Aviation | NEXUS AVIATION | Nigeria | |
| | NIS | Nicaragüense de Aviación | NICA | Nicaragua | |
| | NCN | Nicon Airways | NICON AIRWAYS | Nigeria | Ceased operations 2007 |
| | NGA | Nigeria Airways | NIGERIA | Nigeria | |
| | NGR | Nigerian Air Force | NIGERIAN AIRFORCE | Nigeria | |
| | NGX | Nigerian Global | AIR GLOBAL | Nigeria | |
| | EXT | Nightexpress | EXECUTIVE | Germany | |
| HG | NLY | Niki | FLYNIKI | Austria | |
| | NKV | Nikolaev-Air | AIR NIKOLAEV | Ukraine | Airline of Special Purpose |
| | NSA | Nile Safaris Aviation | NILE SAFARIS | Sudan | |
| | NVA | Nile Valley Aviation Company | | Egypt | defunct |
| | NLW | Nile Wings Aviation Services | NILE WINGS | Sudan | |
| | NBS | Nimbus Aviation | NIMBUS | United Kingdom | |
| | NSR | Nine Star Airways | AIR STAR | Thailand | 2014 |
| KZ | NCA | Nippon Cargo Airlines | NIPPON CARGO | Japan | |
| | NVK | Nizhnevartovskavia | VARTOSKAVIA | Russia | |
| | NOH | No. 32 (The Royal) Squadron | NORTHOLT | United Kingdom | |
| | AKG | No. 84 Squadron RAF | GRIFTER | United Kingdom | |
| | NBL | Nobil Air | NOBIL AIR | Moldova | |
| DD | NOK | Nok Air | NOK AIR | Thailand | |
| XW | NCT | NokScoot | BIG BIRD | Thailand | |
| | NRL | Nolinor Aviation | NOLINOR | Canada | |
| | NMD | Nomad Aviation | NOMAD AIR | Namibia | |
| | OMD | Nomadic Aviation Group LLC | NOMADIC | United States | |
| | NOC | Norcopter | NORCOPTER | Norway | |
| | NEF | Nord-Flyg | NORDEX | Sweden | |
| 5N | AUL | Nordavia | ARCHANGELSK AIR | Russia | |
| JH | NES | Nordeste Linhas Aéreas Regionais | NORDESTE | Brazil | |
| 6N | NRD | Nordic Regional | NORTH RIDER | Sweden | |
| Y7 | TYA | NordStar | TAIMYR | Russia | |
| | NDS | Nordstree (Australia) | | Australia | |
| N4 | NWS | Nordwind Airlines | NORDLAND | Russia | |
| | NRT | Norestair | NORESTAIR | Spain | |
| N5 | | Norfolk Air | | Norfolk Island | Defunct |
| | NCF | Norfolk County Flight College | COUNTY | United Kingdom | |
| | FNA | Norlandair | NORLAND | Iceland | |
| | NOA | Norontair | NORONTAIR | Canada | |
| | HMF | Norrlandsflyg | LIFEGUARD SWEDEN | Sweden | |
| | NRX | Norse Air Charter | NORSE AIR | South Africa | |
| N0 | NBT | Norse Atlantic Airways | LONGSHIP | Norway | |
| Z0 | UBT | Norse Atlantic UK | LONGBOAT | United Kingdom | |
| | NIR | Norsk Flytjeneste | NORSEMAN | Norway | |
| | NOR | Norsk Helikopter | NORSKE | Norway | |
| | DOC | Norsk Luftambulanse | HELIDOC | Norway | |
| | RTV | Nortavia | TIC-TAC | Portugal | |
| | NAI | North Adria Aviation | NORTH-ADRIA | Croatia | |
| NA | NAO | North American Airlines | NORTH AMERICAN | United States | |
| | HMR | North American Charters | HAMMER | Canada | |
| | NAJ | North American Jet Charter Group | JET GROUP | United States | |
| | NAT | North Atlantic Air Inc | MASS AIR | United States | |
| | NFC | North Atlantic Cargo | NORTH ATLANTIC | Norway | |
| | NBN | North British Airlines | TEESAIR | United Kingdom | |
| | NCB | North Caribou Flying Service Ltd | NORTH CARIBOU | Canada | |
| N/A | N/A | North Coast Air Services Ltd | NORTH COAST | Canada | |
| N9 | | North Coast Aviation | | Papua New Guinea | |
| M3 | NFA | North Flying | NORTH FLYING | Denmark | |
| | NRC | North Sea Airways | NORTH SEA | Netherlands | |
| | SBX | North Star Air Cargo | SKY BOX | United States | |
| | NRV | North Vancouver Airlines | NORVAN | Canada | |
| | NWW | North West Airlines | HALANT | Australia | |
| | PTO | North West Geomatics | PHOTO | Canada | |
| | NEN | North-East Airlines | NORTHEAST SWAN | Nigeria | |
| | VBG | North-West Air Transport Company - Vyborg | VYBORG AIR | Russia | |
| HW | NWL | North-Wright Airways | NORTHWRIGHT | Canada | |
| | NLL | Northafrican Air Transport | NORTHAFRICAN AIR | Libya | |
| | NFL | Northaire Freight Lines | GREAT LAKES | United States | |
| | NSF | Northamptonshire School of Flying | NORTON | United Kingdom | |
| | NCE | Northcoast Executive Airlines | TOP HAT | United States | |
| NE | NEE | Northeast Airlines | NORTHEAST | United States | |
| | NPX | Northeast Aviation | NORTHEAST EXPRESS | United States | |
| | NEW | Northeastern Aviation | MEADOW FLIGHT | United States | 2014 |
| NC* | NAC | Northern Air Cargo | YUKON | United States | |
| | BYC | Northern Airlines Sanya | BEIYA | China | |
| | NDA | Northern Airways | NORTHERN DAKOTA | United States | |
| | CMU | Northern Aviation Service | LANNA AIR | Thailand | |
| U7 | | Northern Dene Airways | | Canada | |
| | NEX | Northern Executive Aviation | NEATAX | United Kingdom | |
| | NIC | Northern Illinois Commuter | ILLINOIS COMMUTER | United States | |
| | NTX | Northern Jet Management | NORTAX | United States | |
| 7H | RVF | Northern Pacific Airways | —Raven Flight | United States | |
| | NTA | Northern Thunderbird Air | THUNDERBIRD | Canada | |
| | KOE | Northland Aviation | KOKEE | United States | |
| | NSS | Northstar Aviation | NORTHSTAR | United States | |
| | NHL | Northumbria Helicopters | NORTHUMBRIA | United Kingdom | |
| | NAL | Northway Aviation Ltd | NORTHWAY | Canada | |
| | NWE | Northwest Aero Associates | | United States | |
| NW | NWA | Northwest Airlines | NORTHWEST | United States | defunct merged with Delta Air Lines |
| FY | NWR | Northwest Regional Airlines | | Australia | |
| | NWT | Northwest Territorial Airways | TERRITORIAL | Canada | |
| J3 | PLR | Northwestern Air | POLARIS | Canada | |
| | NWN | Northwinds Northern | NORTHWINDS | Canada | |
| | NAM | Nortland Air Manitoba | MANITOBA | Canada | |
| D8* | IBK | Norwegian Air International | NORTRANS | Ireland | subsidiary of Norwegian Air Shuttle (Ceased operations 2021) |
| DY | NOZ | Norwegian Air Shuttle | NORDIC | Norway | |
| DI | NRS | Norwegian Air UK | REDNOSE* | United Kingdom | subsidiary of Norwegian Air Shuttle (Ceased operations 2021) |
| DN | NAA | Norwegian Air Argentina | NORUEGA | Argentina | subsidiary of Norwegian Air Shuttle (Ceased operations 2019) |
| DU | NLH | Norwegian Long Haul | NORSTAR | Norway | subsidiary of Norwegian Air Shuttle (Ceased operations 2021) |
| DH | NAN | Norwegian Air Norway | NORSHIP | Norway | subsidiary of Norwegian Air Shuttle (transferred sole aircraft back to Norwegian Air Shuttle AOC in 2023) |
| D8 | NSZ | Norwegian Air Sweden | REDNOSE | Sweden | subsidiary of Norwegian Air Shuttle |
| | TFN | Norwegian Aviation College | SPIRIT | Norway | |
| | XNT | Notams International | | United States | |
| BJ | LBT | Nouvel Air Tunisie | NOUVELAIR | Tunisia | |
| O9 | NOV | Nova Airways | NOVANILE | Sudan | |
| | PTR | Nova Scotia Department of Lands and Forests | PATROL | Canada | |
| 1I | NVR | Novair | NAVIGATOR | Sweden | |
| VQ | NVQ | Novo Air | NOVO AIR | Bangladesh | |
| | NVG | Novgorod Air Enterprise | SADKO AVIA | Russia | |
| | NSP | Novosibirsk Aircraft Repairing Plant | NARPAIR | Russia | |
| | NBE | Novosibirsk Aviaenterprise | NAKAIR | Russia | |
| | NPO | Novosibirsk Aviation Production Association | NOVSIB | Russia | |
| | NOY | Noy Aviation | NOY AVIATION | Israel | |
| N6 | ACQ | Nuevo Continente | AERO CONTINENTE | Peru | Operating license revoked by Chile 10/06/2002; Ceased operations 2005; Former name: Aero Continente |
| | NHR | Nuevo Horizonte Internacional | NUEVO HORIZONTE | Mexico | |
| | NUN | Nunasi-Central Airlines | NUNASI | Canada | |
| | NIN | Nurman Avia Indopura | NURVINDO | Indonesia | |
| | NYS | Nyasa Express | NYASA | Malawi | |
| 1I | NJE | NetJets Europe | FRACTION | Portugal | |
| | ORN | Orange Air | ORANGE JET | United States | Allocated in 2014 |
| IP | ONS | One Airlines | AIR DREAMS | Chile | |
| | FET | Old Dominion Freight Lines | FREIGHT LINE | United States | |
| | OCN | O Air | O-BIRD | France | defunct |
| UQ | OCM | O'Connor Airlines | OCONNOR | Australia | Defunct - Bankrupt |
| | DRL | Omni Air Transport | DRILLER | United States | |
| | OWE | Owenair | OWENAIR | South Africa | |
| OB | AAN | Oasis Airlines | Oasis | Spain | defunct |
| O8 | OHK | Oasis Hong Kong Airlines | OASIS | Hong Kong | Defunct |
| | BCN | Ocean Air | BLUE OCEAN | Mauritania | |
| VC | VCX | Ocean Airlines | OCEANCARGO | Italy | |
| | OCS | Ocean Sky UK | OCEANSKY | United Kingdom | |
| | TUK | Ocean Wings Commuter Service | TUCKERNUCK | United States | New Island Connections |
| O2 | | Linear Air | HARPOON | United States | Allocated in 2017 |
| | ODS | Odessa Airlines | ODESSA AIR | Ukraine | |
| | FOC | Office Federal De'Aviation Civile | FOCA | Switzerland | |
| | GBO | Ogooue Air Cargo | | Gabon | |
| | OKJ | Okada Airlines | OKADA AIR | Nigeria | |
| | OKP | Okapi Airways | OKAPI | Democratic Republic of Congo | |
| | OKA | Okay Airways | OKAYJET | China | |
| | OKL | Oklahoma Department of Public Safety | OKLAHOMA | United States | Troop O |
| | OLX | Olimex Aerotaxi | OLIMEX | Czech Republic | |
| | KVK | Olimp Air | PONTA | Kazakhstan | |
| OL | OLT | OLT Express Germany | OLTRA | Germany | |
| OA | OAL | Olympic Air | OLYMPIC | Greece | |
| | OLY | Olympic Aviation | OLAVIA | Greece | |
| WY | OMA | Oman Air | OMAN AIR | Oman | |
| | ORF | Oman Royal Flight | OMAN | Oman | |
| OV | OMS | SalamAir | MAZOON | Oman | Oman’s first Low Cost Carrier |
| | OAV | Omni - Aviacao e Tecnologia | OMNI | Portugal | |
| OY | OAE | Omni Air International | OMNI-EXPRESS | United States | |
| | ONI | OMNI AVIATION TRAINING CENTER | OMNI TRAINING | Portugal | Part of the same group as Omni - Aviacao e Tecnologia |
| | OMF | Omniflys | OMNIFLYS | Mexico | |
| | ORL | On Air Limited | ON AIR | Canada | |
| | OST | Oklahoma State University | OSTATE | United States | |
| | OTG | One Two Go Airlines | THAI EXPRESS | Thailand | |
| | OTM | Onetime Airlines Zambia | ZEDTIME | Zambia | |
| | MED | Ontario Ministry of Health | MEDICAL | Canada | |
| 8Q | OHY | Onur Air | ONUR AIR | Turkey | |
| | OPA | Opal Air | | Australia | |
| | OSA | Open Sky Aviation | | Lebanon | |
| | BOS | OpenSkies | MISTRAL | United Kingdom | |
| | ORR | Operadora Turistica Aurora | TURISTICA AURORA | Mexico | |
| | OLE | Operadora de Lineas Ejecutivas | OPERADORA | Mexico | |
| | OTP | Operadora de Transportes Aéreos | OPERADORA AEREO | Mexico | |
| | OPV | Operadora de Veulos Ejectutivos | OPERADORA DE VUELOS | Mexico | |
| | LLO | Operation Enduring Freedom | APOLLO | Canada | |
| | OAX | Operational Aviation Services | | Australia | |
| | ORD | Orange Air Services | ORANGE SERVICES | Sierra Leone | |
| | ORJ | Orange Air Sierra Leone | ORANGE SIERRA | Sierra Leone | |
| | ORE | Orange Aviation | ORANGE AVIATION | Israel | |
| | ORX | Orbit Express Airlines | OREX | Turkey | |
| | ORK | Orca Air | ORCA TAXI | Egypt | |
| | BUE | Orebro Aviation | BLUELIGHT | Sweden | |
| | ORM | Orel State Air Enterprise | ORPRISE | Russia | |
| R2 | ORB | Orenburg Airlines | ORENBURG | Russia | |
| | OTA | Organizacion De Transportes Aéreos | ORGANIZACION | Mexico | |
| | OML | Organizacoes Mambra | MAMBRA | Angola | |
| | OVV | Orient Air | ORIENTSYR | Syrian Arab Republic | |
| | OTR | Orient Airlines | ORIENTROC | Sudan | |
| | ORN | Orient Airways | ORIENT LINER | Pakistan | |
| OX | OEA | Orient Thai Airlines | ORIENT THAI | Thailand | |
| | NGK | Oriental Air Bridge | ORIENTAL BRIDGE | Japan | |
| | OAC | Oriental Airlines | ORIENTAL AIR | Nigeria | |
| QO | OGN | Origin Pacific Airways | ORIGIN | New Zealand | |
| | OED | Orion Air Charter | ORION CHARTER | South Africa | |
| | OIX | Orion-x | ORIONIX | Russia | |
| | KOV | Orlan-2000 | ORLAN | Kazakhstan | |
| | RNG | Orange Aircraft Leasing | ORANGE | Netherlands | |
| | OAD | Orscom Tourist Installations Company | ORSCOM | Egypt | |
| | JPA | OSACOM | J-PAT | United States | United States Army |
| | OSH | Osh Avia | OSH AVIA | Kyrgyzstan | |
| | OCO | Ostend Air College | AIR COLLEGE | Belgium | |
| | ODY | Odyssey International | ODYSSEY | Canada | |
| | FNL | Oulun Tilauslento | FINN FLIGHT | Finland | |
| ON | RON | Our Airline | OUR AIRLINE | Nauru | formerly Air Nauru |
| | OOT | Out Of The Blue Air Safaris | OOTBAS | South Africa | |
| OJ | OLA | Overland Airways | OVERLAND | Nigeria | |
| | OAR | ONE AIR | BOSS AIR | Spain | |
| | OXE | Oxaero | OXOE | United Kingdom | |
| | WDK | Oxford Air Services | WOODSTOCK | United Kingdom | |
| | OAA | Oxley Aviation | | Australia | |
| OZ | OZR | Ozark Air Lines | OZARK | United States | Defunct |
| O7 | OZJ | OzJet | AUSJET | Australia | |
| | OSU | Ohio State University | SCARLET | United States | |
| OA | OAL | Olympic Airlines | OLYMPIC | Greece | Defunct |
| OB | AAN | Oasis International Airlines Now assigned to Boliviana de Aviacion (BoA) | OASIS | Spain | Ceased operations |
| | ORT | Ortac | SKYWALKER | Jersey | |
| | PIP | Pilot Flight Academy | PILOT | Norway | |
| | HRS | Pursuit Aviation | HORSEMAN | United States | 2016 |
| | NCT | Pete Air | PETE AIR | Thailand | 2014 |
| | PRT | Prime Service Italia | PRIME ITALIA | Italy | 2014 |
| | PXT | Pacific Coast Jet | PACK COAST | United States | Allocated in 2014 |
| | BPH | Phoenix Helicopter Academy | BLACK PHOENIX | United Kingdom | |
| | PFY | Pel-Air Aviation | PELFLIGHT | Australia | |
| | PXR | Pixair Survey | PIXAIR | France | |
| | PNC | Prince Aviation | PRINCE | Serbia | |
| | PMI | Primero Transportes Aereos | AEROEPRIM | Mexico | |
| | KTL | P & P Floss Pick Manufacturers | KNOTTSBERRY | South Africa | |
| | PCR | PAC Air | PACAIR | United States | Pearson Aviation Corporation |
| PV | PNR | PAN Air | SKYJET | Spain | |
| 9Q | PBA | PB Air | PEEBEE AIR | Thailand | |
| | PDQ | PDQ Air Charter | DISPATCH | United States | |
| | XAS | PHH Aviation System | | United States | |
| | PDG | PLM Dollar Group | OSPREY | United Kingdom | |
| PU | PUA | PLUNA | PLUNA | Uruguay | |
| U4 | PMT | PMTair | MULTITRADE | Cambodia | Progress Multitrade |
| | PRP | PRT Aviation | PRONTO | Spain | |
| OH | JIA | PSA Airlines | BLUE STREAK | United States | part of American Airlines Group |
| | KST | PTL Luftfahrtunternehmen | KING STAR | Germany | |
| | WIS | Paccair | WISCAIR | United States | |
| Y5 | PCE | Pace Airlines | PACE | United States | Pace Airlines was purchased by Hooters in December 2002. |
| | PAB | Pacific Air Boats | AIR BOATS | Canada | |
| | PRC | Pacific Air Charter | PACIFIC CHARTER | United States | |
| | PAQ | Pacific Air Express | SOLPAC | Solomon Islands | Registered Solomon Islands, main base in Brisbane, Australia |
| | PXP | Pacific Air Transport | PAK EXPRESS | United States | |
| BL | PIC | Pacific Airlines | PACIFIC AIRLINES | Vietnam | |
| | PAK | Pacific Alaska Airlines | PACIFIC ALASKA | United States | |
| | PCV | Pacific Aviation (Australia) | PACAV | Australia | |
| | PTO | European Flight Academy / Lufthansa Aviation Training | ROOKIE | Germany | |
| | PCX | Pacific Aviation (United States) | | United States | |
| DJ | PBN | Pacific Blue | BLUEBIRD | New Zealand | Controlled Dupe IATA with Virgin Australia |
| | PQA | Pacific Coast Airlines | SAGE BRUSH | United States | |
| 8P | PCO | Pacific Coastal Airlines | PASCO | Canada | |
| Q8 | PEC | Pacific East Asia Cargo Airlines | PAC-EAST CARGO | Philippines | |
| | PFA | Pacific Flight Services | PACIFIC SING | Singapore | |
| | PIN | Pacific International Airlines | ROAD RUNNERS | United States | |
| | PSA | Pacific Island Aviation | PACIFIC ISLE | United States | |
| | PCJ | Pacific Jet | PACIFIC JET | United States | |
| | PPM | Pacific Pearl Airways | PACIFIC PEARL | Philippines | |
| | PAR | Pacific Rim Airways | PACRIM | Australia | |
| LW | NMI | Pacific Wings | TSUNAMI | United States | |
| GX | | Pacificair | | Philippines | |
| | PFR | Pacificair Airlines | PACIFIC WEST | United States | |
| | RCY | Package Express | RACE CITY | United States | |
| | PAE | Paisajes Españoles | PAISAJES | Spain | |
| | PKW | Pak West Airlines | PLATINUM WEST | United States | |
| PK | PIA | Pakistan International Airlines | PAKISTAN | Pakistan | |
| | PKR | Pakker Avio | PAKKER AVIO | Estonia | |
| | LPA | Pal Aerolíneas | LINEASPAL | Mexico | |
| | PPC | Palau Asia Pacific Airlines | PALAU ASIAPAC | Palau | |
| | PNA | Palau National Airlines | SEBUS | Palau | 2014 |
| GP | PTP | Palau Trans Pacific Airlines | TRANS PACIFIC | Palau | |
| PF | PNW | Palestinian Airlines | PALESTINIAN | Egypt | |
| | JSP | Palmer Aviation | PALMER | United Kingdom | |
| NR | PIR | Pamir Airways | PAMIR | Afghanistan | |
| | PFN | Pan African Air Services | PANAFRICAN | Sierra Leone | |
| | ODM | Pan African Airways | | Kenya | |
| | PAX | Pan Air | PANNEX | United States | |
| | XPA | Pan Am Weather Systems | | United States | |
| 7N | PWD | PAWA Dominicana | | Dominican Republic | |
| PN | | Pan American Airways | | United States | defunct |
| PA | PAA | Pan American Airways | | United States | defunct |
| PA | PAA | Pan American World Airways | CLIPPER | United States | defunct 1991 |
| | PEA | Pan Europeenne Air Service | | France | |
| | PHT | Pan Havacilik Ve Ticaret | PANANK | Turkey | |
| | PMA | Pan Malaysian Air Transport | PAN MALAYSIA | Malaysia | |
| | PNC | Pan-Air | PANAIRSA | Mexico | |
| | PNF | Panafrican Airways | PANWAYS | Ivory Coast | defunct |
| | PGI | Panagra Airways | PANAGRA | United States | |
| | RSL | Panama Aircraft Rental and Sales | PANAMA RENTAL | Panama | 2014 |
| | PEI | Panamedia | PANAMEDIA | Spain | |
| | PVI | Panavia | | Panama | |
| | PNH | Panh | KUBAN LIK | Russia | |
| | PHU | Pannon Air Service | PANNON | Hungary | |
| | PNM | Panorama | PANORAMA | Spain | |
| | PAH | Panorama Air Tour | LANI | United States | |
| | AFD | Panorama Flight Service | AIRFED | United States | |
| P8 | PTN | Pantanal Linhas Aéreas | PANTANAL | Brazil | |
| | HMP | Papair Terminal | PAPAIR TERMINAL | Haiti | |
| | PAI | Paradise Airways | SEA RAY | United States | |
| | PDI | Paradise Island Airways | PARADISE ISLAND | United States | |
| | PGX | Paragon Air Express | PARAGON EXPRESS | United States | |
| | PGF | Paragon Global Flight Support | | United Kingdom | |
| | PRR | Paramount Airlines | PARAMOUNT | Sierra Leone | |
| I7 | PMW | Paramount Airways | PARAWAY | India | |
| | APE | Parcel Express | AIR PARCEL | United States | |
| | IRE | Pariz Air | PARIZAIR | Iran | |
| | PRA | Pars Aviation Service | PARSAVIA | Iran | |
| | PST | Parsa | TURISMO REGIONAL | Panama | |
| | FAP | Parsons Airways Northern | | Canada | |
| | PSC | Pascan Aviation | PASCAN | Canada | |
| P3 | PTB | Passaredo Transportes Aéreos | PASSAREDO | Brazil | |
| | PTC | Patria Cargas Aéreas | PATRIA | Argentina | |
| | BYT | Patriot Aviation Limited | BYTE | United Kingdom | |
| | ETL | Patterson Aviation Company | ENTEL | United States | |
| | PHE | Pawan Hans | PAWAN HANS | India | |
| | IRP | Payam Air | PAYAMAIR | Iran | Air Center Service |
| | KGC | Peach Air | GOLDCREST | United Kingdom | |
| | PRL | Pearl Air | PEARL LINE | Pakistan | |
| | PBY | Pearl Air Services | PEARL SERVICES | Uganda | |
| HP | HPA | Pearl Airways | PEARL AIRWAYS | Haiti | IATA code withdrawn |
| | PVU | Peau Vavaʻu | PEAU | Tonga | |
| | PXA | Pecotox Air | PECOTOX | Moldova | |
| PC | PGT | Pegasus Airlines | SUNTURK | Turkey | WAS 1I, H9 |
| PE | PEV | People's | PEOPLES | Austria | Previously used by Pegaviation, and PeopleExpress (US low cost carrier 1981-87) |
| 1I | | Pegasus Hava Tasimaciligi | Sunturk | Turkey | |
| | HAK | Pegasus Helicopters | HELIFALCON | Norway | |
| | PDF | Pelican Air Services | PELICAN AIRWAYS | South Africa | |
| | PEX | Pelican Express | PELICAN EXPRESS | United States | |
| | PAS | Pelita Air Service | PELITA | Indonesia | |
| | PEM | Pem-Air | PEM-AIR | Canada | |
| | PDY | Pen-Avia | PENDLEY | United Kingdom | |
| KS | PEN | Peninsula Airways | PENINSULA | United States | |
| | PNE | Peninter Aérea | PENINTER | Mexico | |
| | PCA | Penya De L'Aire | PENA DEL AIRE | Spain | |
| | CVT | Peran | CVETA | Kazakhstan | |
| | PCC | Perforadora Central | PERFORADORA CENTRAL | Mexico | |
| | PAG | Perimeter Aviation | PERIMETER | Canada | |
| P9 | PGP | Perm Airlines | PERM AIR | Russia | |
| | PPQ | Personas Y Pasquetes Por Air | PERSONSPAQ | Mexico | |
| P9 | PVN | Peruvian Airlines | | Peru | |
| | FPR | Peruvian Air Force | | Peru | Fuerza Aérea Del Perú |
| | INP | Peruvian Navy | | Peru | |
| | PEO | Petro Air | PETRO AIR | Libya | |
| | PMX | Petroleos Mexicanos | PEMEX | Mexico | |
| | PHM | Petroleum Helicopters | PETROLEUM | United States | |
| | PHC | Petroleum Helicopters de Colombia | HELICOPTERS | Colombia | |
| | PTK | Petropavlovsk-Kamchatsk Air Enterprise | PETROKAM | Russia | |
| | PTY | Petty Transport | PETTY | United States | |
| | PHV | Phenix Aviation | NEW BIRD | France | |
| | PMY | Phetchabun Airline | PHETCHABUN AIR | Thailand | |
| Z2 | EZD | Philippines AirAsia | REDHOT | Philippines | |
| PR | PAL | Philippine Airlines | PHILIPPINE | Philippines | |
| | PHI | Philips Aviation Services | PHILAIR | Netherlands | ICAO code and call sign no longer allocated |
| | BCH | Phillips Air | BEACHBALL | United States | |
| | PDD | Phillips Alaska | PADA | United States | |
| | PHL | Phillips Michigan City Flying Service | PHILLIPS | United States | |
| | PHB | Phoebus Apollo Aviation | PHOEBUS | South Africa | |
| | KZM | Phoebus Apolloa Zambia | CARZAM | Zambia | |
| | PHA | Phoenix Air Group | GRAY BIRD | United States | |
| | PHN | Phoenix Air Lines | PHOENIX BRASIL | Brazil | |
| | PAM | Phoenix Air | PHOENIX | Germany | |
| | PPG | Phoenix Air Transport | PAPAGO | United States | |
| | WDY | Phoenix Airline Services | WINDYCITY | United States | |
| HP | | Phoenix Airways | | Switzerland | |
| | PHY | Phoenix Avia | PHOENIX ARMENIA | Armenia | |
| | PHG | Phoenix Aviation | PHOENIX GROUP | Kyrgyzstan | |
| | XPX | Phoenix Flight Operations | | United States | |
| 9R | VAP | Phuket Air | PHUKET AIR | Thailand | |
| PI | PAI | Piedmont Airlines (1948-1989) | PIEDMONT | United States | defunct |
| | PDT | Piedmont Airlines | PIEDMONT | United States | part of American Airlines Group |
| | PCH | Pilatus Flugzeugwerke | PILATUS WINGS | Switzerland | |
| | PLU | Pilatus PC-12 Center De Mexico | PILATUS MEXICO | Mexico | |
| | MKS | Pimichikamac Air | MIKISEW | Canada | |
| | PNP | Pineapple Air | PINEAPPLE AIR | Bahamas | |
| | PIM | Pinframat | PINFRAMAT | Angola | |
| | PCL | Pinnacle Air Group | PINNACLE GROUP | United States | |
| 9E | FLG | Pinnacle Airlines | FLAGSHIP | United States | |
| | PIO | Pioneer Airlines | PIONEER | United States | |
| | PER | Pioneers Limited | | Pakistan | |
| | PRN | Pirinair Express | PRINAIR EXPRESS | Spain | |
| | PLN | Planar | PLANAR | Angola | |
| | PMS | Planemaster Services | PLANEMASTER | United States | |
| | PLZ | Planet Airways | PLANET | United States | |
| OG | FPY | Play | PLAYER | Iceland | |
| | PYZ | Players Air | PLAYERS AIR | United States | |
| | LIB | Polizeihubschrauberstaffel Hamburg | LIBELLE | Germany | |
| | PSF | Plymouth School of Flying | LIZARD | United Kingdom | |
| DP | PBD | Pobeda | POBEDA | Russia | |
| | POC | Pocono Air Lines | POCONO | United States | |
| | PDA | Podilia-Avia | PODILIA | Ukraine | |
| | PAZ | Point Afrique Niger | POINTAIR NIGER | Niger | |
| | RMI | Point Airlines | POINT AIRLINE | Nigeria | |
| | PAW | Pointair Burkina | POINTAIR BURKINA | Burkina Faso | |
| | PTS | Points of Call Airlines | POINTSCALL | Canada | |
| PO | PAC | Polar Air Cargo | POLAR | United States | |
| | PMO | Polar Airlines de Mexico | POLAR MEXICO | Mexico | |
| | PSR | Polestar Aviation | POLESTAR | United Kingdom | |
| | POT | Polet Flight | POLET | Russia | |
| | POF | Police Aux Frontières | AIRPOL | France | |
| | PLC | Police Aviation Services | SPECIAL | United Kingdom | |
| | PLF | Polish Air Force | POLISH AIRFORCE | Poland | |
| | PNY | Polish Navy | POLISH NAVY | Poland | |
| | NRW | Polizeifliegerstaffel Nordrhein-Westfalen | HUMMEL | Germany | |
| | PPH | Polizeihubschrauberstaffel Niedersachsen | POLICE PHOENIX | Germany | |
| | PIK | Polizeihubschrauberstaffel Sachsen-Anhalt | POLICE IKARUS | Germany | |
| | SRP | Polizeihubschauberstaffel Rheinland-Pfalz | SPERBER | Germany | |
| | PBW | Polizeihubschrauberstaffel Baden-Württemberg | BUSSARD | Germany | |
| | EDL | Polizeihubschrauberstaffel Bayern | POLICE EDELWEISS | Germany | |
| | PBB | Polizeihubschrauberstaffel Brandenburg | ADEBAR | Germany | |
| | PHH | Polizeihubschrauberstaffel Hessen | IBIS | Germany | |
| | PMV | Polizeihubschrauberstaffel Mecklenburg-Vorpommern | POLICE MERLIN | Germany | |
| | PHS | Polizeihubschrauberstaffel Sachsen | PASSAT | Germany | |
| | HBT | Polizeihubschrauberstaffel Thüringen | HABICHT | Germany | |
| | CUK | Polo Aviation | CHUKKA | United Kingdom | |
| | PLA | Polynesian Air-Ways | POLYAIR | United States | |
| PH | PAO | Polynesian Airlines | POLYNESIAN | Samoa | |
| DJ | PLB | Polynesian Blue | POLYBLUE | New Zealand | Controlled Dupe IATA, Code reserved but not in use, PBN (Bluebird) used. |
| 1U | | Polyot Sirena | | Russia | |
| | PND | Pond Air Express | POND AIR | United States | |
| | PSI | Pont International Airline Services | PONT | Suriname | defunct |
| | PLX | Pool Aviation | POOLEX | United Kingdom | |
| | PTQ | Port Townsend Airways | TOWNSEND | United States | |
| | POR | Porteadora De Cosola | PORTEADORA | Mexico | |
| PD | POE | Porter Airlines | PORTER | Canada | |
| NI | PGA | Portugalia | PORTUGALIA | Portugal | |
| | AFP | Portuguese Air Force | PORTUGUESE AIR FORCE | Portugal | |
| | POA | Portuguese Army | PORTUGUESE ARMY | Portugal | |
| | PON | Portuguese Navy | PORTUGUESE NAVY | Portugal | |
| M4 | MSA | Poste Air Cargo | AIRMERCI | Italy | |
| BK | PDC | Potomac Air | DISTRICT | United States | |
| | PSN | Potosina Del Aire | POTOSINA | Mexico | |
| | PWL | Powell Air | POWELL AIR | Canada | |
| | PFS | Prairie Flying Service | PRAIRIE | United States | |
| | PWC | Pratt and Whitney Canada | PRATT | Canada | |
| PW | PRF | Precision Air | PRECISION AIR | Tanzania | |
| | PRE | Precision Airlines | PRECISION | United States | |
| | BAT | Premiair | BALLISTIC | Luxembourg | |
| | PGL | Premiair Aviation Services | PREMIERE | United Kingdom | |
| | PME | Premiair Flying Club | ADUR | United Kingdom | |
| | EMI | Premium Air Shuttle | BLUE SHUTTLE | Nigeria | |
| | PMU | Premium Aviation | PREMIUM | Germany | |
| | BFA | Presidence Du Faso | | Burkina Faso | |
| | ONM | Presidencia de La Republica de Guinea Ecuatorial | | Equatorial Guinea | |
| TO | PSD | President Airlines | | Cambodia | |
| MO | AUH | Presidential Flight | SULTAN | United Arab Emirates | Presidential flight |
| | PRD | Presidential Aviation | PRESIDENTIAL | United States | |
| | PWA | Priester Aviation | PRIESTER | United States | |
| | PMM | Paradigm Air Operators | PARADIGM | United States | |
| FE | WCP | Primaris Airlines | WHITECAP | United States | |
| | PMC | Primas Courier | PRIMAC | United States | |
| | CRY | Primavia Limited | CARRIERS | United Kingdom | |
| | PRM | Prime Airlines | PRIME AIR | United States | |
| | PKZ | Prime Aviation | PRAVI | Kazakhstan | |
| | CME | Prince Edward Air | COMET | Canada | |
| | PJP | Princely Jets | PRINCELY JETS | Pakistan | |
| 8Q | | Princess Air | | | no longer assigned |
| | PCN | Princeton Aviation Corporation | PRINCETON | United States | |
| | PRY | Priority Air Charter | PRIORITY AIR | United States | |
| | PAT | Priority Air Transport | PAT | United States | Department of the Army |
| | BCK | Priority Aviation Company | BANKCHECK | United States | |
| | PTI | Privatair | PRIVATAIR | Switzerland | |
| | PJE | Private Jet Expeditions | PEE JAY | United States | |
| | PJA | Private Jet Management | PRIVATE FLIGHT | United States | |
| 8W | PWF | Private Wings Flugcharter | PRIVATE WINGS | Germany | |
| P6 | PVG | Privilege Style Líneas Aéreas | PRIVILEGE | Spain | |
| | PRH | Pro Air | PROHAWK | United States | |
| | PSZ | Pro Air Service | POP-AIR | United States | |
| | GIY | Probiz Guinee | PROBIZ | Guinea | |
| | PAD | Professional Express Courier Service | AIR PROFESSIONAL | United States | |
| | PVL | Professione VOlare | VOLARE | Italy | |
| P0 | PFZ | Proflight Zambia | PROFLIGHT-ZAMBIA | Zambia | |
| | PTT | Promotora Industria Totolapa | TOTOLAPA | Mexico | |
| | PRO | Propair | PROPAIR | Canada | |
| | PPA | Propheter Aviation | AIR PROP | United States | |
| | PTH | Proteus Helicopteres | PROTEUS | France | |
| | PTL | Providence Airline | PLANTATION | United States | |
| | AWD | Providence Aviation Services | | Pakistan | |
| PB | SPR | Provincial Airlines | SPEEDAIR | Canada | |
| | PRV | Provincial Express | PROVINCIAL | Canada | |
| | PSW | Pskovavia | PSKOVAVIA | Russia | |
| | UDA | Psudiklat Perhubungan Udara/PLP | UDARA | Indonesia | |
| | PTA | Ptarmigan Airways | PTARMIGAN | Canada | |
| | PSP | Publiservicios Aéreos | PUBLISERVICIOS | Mexico | |
| | PUV | Publivoo | PUBLIVOO | Portugal | Publicidade e Imagens Aéreas |
| | PNG | Puerto Rico National Guard | | United States | |
| | TXV | Puerto Vallarta Taxi Aéreo | TAXIVALLARTA | Mexico | |
| | PGH | Pulkovo Aircraft Services | | Russia | |
| | PLY | Puma Linhas Aéreas | PUMA BRASIL | Brazil | |
| | PTV | Puntavia Air Services | PUNTAVIA | Djibouti | |
| | MGO | Punto Fa | MANGO | Spain | |
| | PYR | Pyramid Air Lines | PYAIR | Egypt | |
| FV | PLK | Pulkovo Aviation Enterprise | PULKOVO | Russia | defunct merged into Rossiya (airline) |
| | PRI | Primera Air Scandinavia | PRIMERA | Denmark | |
| | PRW | Primera Air Nordic | JETBIRD | Latvia | |
| | FQA | Quikjet Airlines | QUIK LIFT | India | 2014 |
| | QQE | Qatar Executive | | Qatar | |
| | QNT | Qanot Sharq | QANAT SHARQ | Uzbekistan | |
| QF | QFA | Qantas | QANTAS | Australia | |
| QF | QLK | QantasLink | QLINK | Australia | Turbo-Props |
| QF | QJE | QantasLink | QJET | Australia | Qantaslink Jet Operations |
| | QAC | Qatar Air Cargo | QATAR CARGO | Qatar | |
| QR | QTR | Qatar Airways | QATARI | Qatar | |
| | QAF | Qatar Amiri Flight | AMIRI | Qatar | |
| QB | QSM | Qeshm Air | QESHM AIR | Iran | |
| QW | QDA | Qingdao Airlines | SKY LEGEND | China | |
| | QTX | Quantex Environmental | AIR QUANTEX | Canada | |
| | QUE | Quebec Government Air Service | QUEBEC | Canada | |
| | QNA | Queen Air | QUEEN AIR | Dominican Republic | |
| | LBQ | Quest Diagnostics | LABQUEST | United States | |
| | QAJ | Quick Air Jet Charter | DAGOBERT | Germany | |
| | QAH | Quick Airways Holland | QUICK | Netherlands | |
| | QAS | Quisqueya Airlines | QUISQUEYA | Haiti | |
| | QAQ | Qurinea Air Service | QURINEA AIR | Libya | |
| | QCC | Qwest Commuter Corporation | QWEST AIR | United States | |
| | QWA | Qwestair | | Australia | |
| | QWL | Qwila Air | Q-CHARTER | South Africa | |
| | RBB | Rabbit-Air | RABBIT | Switzerland | |
| | ACE | Race Cargo Airlines | Fastcargo | Ghana | defunct |
| R6 | | RACSA | | Guatemala | |
| | GBR | Rader Aviation | GREENBRIER AIR | United States | |
| 1D | | Radixx | | United States | |
| | BKH | RAF Barkston Heath | | United Kingdom | |
| | CFN | RAF Church Fenton | CHURCH FENTON | United Kingdom | Church Fenton Flying Training Unit |
| | COH | RAF Coltishall | COLT | United Kingdom | Coltishall Flying Training Unit |
| | CBY | RAF Coningsby | TYPHOON | United Kingdom | Coningsby Flying Training Unit |
| | COT | RAF Cottesmore | COTTESMORE | United Kingdom | Royal Air Force (Cottesmore Flying Training Unit) - No longer allocated |
| | CWL | RAF Cranwell | CRANWELL | United Kingdom | Royal Air Force (Cranwell Flying Training Unit) |
| | KIN | RAF Kinloss | KINLOSS | United Kingdom | Royal Air Force (Kinloss Flying Training Unit) |
| | LEE | RAF Leeming | JAVELIN | United Kingdom | Royal Air Force (Leeming Flying Training Unit) |
| | LCS | RAF Leuchars | LEUCHARS | United Kingdom | Royal Air Force |
| | LOP | RAF Linton-on-Ouse | LINTON ON OUSE | United Kingdom | Royal Air Force (Linton-on-Ouse Flying Training Unit) |
| | LOS | RAF Lossiemouth | LOSSIE | United Kingdom | Royal Air Force (Lossiemouth Flying Training Unit) |
| | MRH | RAF Marham | MARHAM | United Kingdom | Royal Air Force (Marham Flying Training Unit) |
| | NWO | RAF Northwood | | United Kingdom | Royal Air Force (Northwood Headquarters) |
| | SMZ | RAF Scampton | SCAMPTON | United Kingdom | Royal Air Force |
| | STN | RAF St Athan | SAINT ATHAN | United Kingdom | Royal Air Force |
| | SMG | RAF St Mawgan Search and Rescue | | United Kingdom | Royal Air Force |
| | TOF | RAF Topcliffe Flying Training Unit | TOPCLIFFE | United Kingdom | Royal Air Force |
| | VYT | RAF Valley Flying Training Unit | ANGLESEY | United Kingdom | Royal Air Force |
| | VLL | RAF Valley SAR Training Unit | | United Kingdom | Royal Air Force |
| | WAD | RAF Waddington | VULCAN | United Kingdom | Royal Air Force (Waddington FTU) |
| | WIT | RAF Wittering | STRIKER | United Kingdom | Royal Air Force (Wittering FTU) |
| | MTL | RAF-Avia | MITAVIA | Latvia | |
| | WES | Rainbow International Airlines | WEST INDIAN | United States | |
| | RJT | RA Jet Aeroservicios | RA JET | Mexico | |
| | RAJ | Raji Airlines | RAJI | Pakistan | |
| | RKM | RAK Airways | RAKAIR | United Arab Emirates | |
| | RFA | Raleigh Flying Service | RALEIGH SERVICE | United States | |
| | REX | Ram Air Freight | RAM EXPRESS | United States | |
| | RMT | Ram Aircraft Corporation | RAM FLIGHT | United States | |
| | PPK | Ramp 66 | PELICAN | United States | |
| | RGM | Rangemile Limited | RANGEMILE | United Kingdom | |
| | MWR | Raslan Air Service | RASLAN | Egypt | |
| | RAQ | Rath Aviation | RATH AVIATION | Austria | |
| | CSM | Ratkhan Air | LORRY | Kazakhstan | |
| | RVR | Raven Air | RAVEN | United Kingdom | |
| | RVN | Raven Air | RAVEN U-S | United States | Qualiflight Training |
| 7H | RVF | Ravn Alaska | RAVEN FLIGHT | United States | 2014 |
| | REI | Ray Aviation | RAY AVIATION | Israel | |
| | RYT | Raya Jet | | Jordan | |
| | RTN | Raytheon Aircraft Company | RAYTHEON | United States | |
| | RCJ | Raytheon Corporate Jets | NEWPIN | United Kingdom | |
| | KSS | Raytheon Travel Air | KANSAS | United States | |
| | RCB | Real Aero Club De Baleares | BALEARES | Spain | |
| | CDT | Real Aero Club de Reus-Costa Dorado | AEROREUS | Spain | |
| | RCD | Real Aeroclub De Tenerife | AEROCLUB | Spain | |
| | VCB | Real Aero Club de Vizcaya | | Spain | |
| | RLV | Real Aviation | REAL | Ghana | |
| XW | LUV | Really Cool Airlines | REALLY COOL AIRLINE | Thailand | |
| | RCB | Real Aero Club De Baleares | BALEARES | Spain | |
| REB | Rebus | REBUS | Bulgaria | |
| | RTO | Rectimo Air Transports | RACCOON | France | |
| | RIX | Rectrix Aviation | RECTRIX | United States | |
| | PSH | Red Aviation | PASSION | United Kingdom | (Helidrome Limited) |
| | RBN | Red Baron Aviation | RED BARON | United States | |
| | DEV | Red Devils Parachute Display Team | RED DEVILS | United Kingdom | |
| | RDV | Red Sea Aviation | RED AVIATION | Egypt | |
| | RSV | Red Sky Ventures | RED SKY | Namibia | |
| | STR | Red Star | STARLINE | United Arab Emirates | |
| 8L | RHC | Redhill Aviation | REDAIR | United Kingdom | |
| | VRD | Virgin America | REDWOOD | United States | |
| | RAV | Reed Aviation | REED AVIATION | United Kingdom | |
| | REF | Reef Air | REEF AIR | New Zealand | |
| V4 | REK | Reem Air | REEM AIR | Kyrgyzstan | |
| | RVV | Reeve Aleutian Airways | REEVE | United States | defunct |
| | RBH | Regal Bahamas International Airways | CALYPSO | Bahamas | |
| | RGY | Regency Airlines | REGENCY | United States | |
| | RAH | Regent Air | REGENT | Canada | |
| RX | RGE | Regent Airways | REGENT | Bangladesh | defunct; code reassigned to Riyadh Air |
| | RAG | Regio Air | GERMAN LINK | Germany | |
| | RGR | Region Air | REGIONAIR | Canada | |
| YS | RAE | Régional | REGIONAL EUROPE | France | |
| | TSH | R1 Airlines, previously Regional 1 | TRANSCANADA | Canada | |
| | RIL | Regional Air | | Mauritania | |
| | REW | Regional Air Express | REGIONAL WINGS | Germany | |
| | REG | Regional Air Services | REGIONAL SERVICES | Tanzania | |
| FN | RGL | Regional Air Lines | MAROC REGIONAL | Morocco | |
| ZL | RXA | Regional Express | REX | Australia | |
| | JJM | Regional Geodata Air | GEODATA | Spain | |
| P7 | REP | Regional Paraguaya | REGIOPAR | Paraguay | Defunct |
| 3C | CEA | RegionsAir | CORP-X | United States | formerly Corporate Airlines |
| | REL | Reliance Aviation | RELIANCE AIR | United States | |
| | RLI | Reliant Air | RELIANT | United States | |
| | RTS | Relief Transport Services | RELIEF | United Kingdom | |
| | RAN | Renan | RENAN | Moldova | |
| QQ | ROA | Reno Air | RENO AIR | United States | defunct |
| | RGS | Renown Aviation | RENOWN | United States | |
| RC | REP | Republic Airlines | REPUBLIC | United States | defunct; 1979–1986, merged with Northwest Airlines |
| YX | RPA | Republic Airways | BRICKYARD | United States | |
| RH | RPH | Republic Express Airlines | PUBLIC EXPRESS | Indonesia | |
| | RBC | Republicair | REPUBLICAIR | Mexico | |
| | RST | Resort Air | RESORT AIR | United States | |
| | RUT | Reut Airways | YADID | Israel | |
| | RGV | RG Aviation | | Venezuela | 2014 |
| | RDS | Rhoades Aviation | RHOADES EXPRESS | United States | |
| | RIU | Riau Airlines | RIAU AIR | Indonesia | |
| | RIA | Rich International Airways | RICHAIR | United States | |
| | RVC | Richards Aviation | RIVER CITY | United States | |
| | RIC | Richardson's Airway | RICHARDSON | United States | |
| | RCA | Richland Aviation | RICHLAND | United States | |
| | WHH | Richy Skylark | | Sri Lanka | 2014 |
| | HPR | Rick Lucas Helicopters | HELIPRO | New Zealand | |
| C7 | RLE | Rico Linhas Aéreas | RICO | Brazil | |
| | RID | Ridder Avia | AKRID | Kazakhstan | |
| | RAK | Riga Airclub | SPORT CLUB | Latvia | |
| | RAZ | Rijnmond Air Services | RIJNMOND | Netherlands | |
| | POL | Rikspolisstyrelsen | | Sweden | |
| | RIM | Rimrock Airlines | RIMROCK | United States | |
| | SKA | Rio Air Express | RIO EXPRESS | Brazil | |
| | REO | Rio Airways | RIO | United States | |
| E2 | GRN | Rio Grande Air | GRANDE | United States | defunct |
| RL | RIO | Rio Linhas Aéreas | RIO | Brazil | |
| SL | RSL | Rio Sul Serviços Aéreos Regionais | RIO SUL | Brazil | defunct |
| | RVM | River Ministries Air Charter | RIVER | South Africa | |
| | RGP | River State Government of Nigeria | GARDEN CITY | Nigeria | |
| | UNR | Rivne Universal Avia | RIVNE UNIVERSAL | Ukraine | |
| RX | RXI | Riyadh Air | RIYADH AIR | Saudi Arabia | Launching in 2025 |
| | RDL | Roadair Lines | ROADAIR | Canada | |
| | RBT | Robinton Aero | ROBIN | Dominican Republic | |
| V2 | RBY | Vision Airlines | RUBY | United States | Charter Airline and Las Vegas Tours |
| | ROX | Roblex Aviation | ROBLEX | United States | |
| | RKW | Rockwell Collins Avionics | ROCKWELL | United States | |
| | ROC | Rocky Mountain Airlines | | Canada | |
| | RMA | Rocky Mountain Airways | ROCKY MOUNTAIN | United States | |
| | LIF | Rocky Mountain Holdings | LIFECARE | United States | |
| | RDZ | Rodze Air | RODZE AIR | Nigeria | |
| | FAD | Rog-Air | AIR FRONTIER | Canada | |
| | RRZ | Rollright Aviation | ROLLRIGHT | United Kingdom | |
| | RRL | Rolls-Royce Limited | MERLIN | United Kingdom | Military Aviation |
| | BTU | Rolls-Royce plc | ROLLS | United Kingdom | Rolls-Royce Bristol Engine Division |
| | ROF | Romanian Air Force | ROMAF | Romania | |
| | RMV | Romavia | AEROMAVIA | Romania | |
| | RNS | Ronso | RONSO | Mexico | |
| | ROR | Roraima Airways | RORAIMA | Guyana | |
| | KRS | Rosen Aviation | | Japan | 2014 |
| | RNB | Rosneft-Baltika | ROSBALT | Russia | |
| | NRG | Ross Aviation | ENERGY | United States | |
| | RFS | Rossair | | Australia | |
| | RSS | Rossair | ROSS CHARTER | South Africa | |
| | ROS | Rossair Europe | CATCHER | Netherlands | |
| FV | SDM | Rossiya | RUSSIA | Russia | Airline merged with Pulkovo Aviation Enterprise and renamed to Rossiya |
| | RAL | Roswell Airlines | ROSWELL | United States | |
| GZ | RAR | Air Rarotonga | AIR RAROTONGA | Cook Islands | |
| | RTR | Rotatur | ROTATUR | Brazil | |
| | RKT | Rotormotion | ROCKET | United Kingdom | |
| | JCR | Rotterdam Jet Center | ROTTERDAM JETCENTER | Netherlands | |
| | ROV | Rover Airways International | ROVERAIR | United States | |
| | VOS | Rovos Air | ROVOS | South Africa | |
| | RCG | Royal Air Cargo | ROYAL CARGO | South Africa | |
| RR | RFR | Royal Air Force | RAFAIR | United Kingdom | |
| RS | MJN | Royal Air Force of Oman | MAJAN | Oman | |
| | ACW | Royal Air Force | AIR CADET | United Kingdom | Air Cadet Schools |
| | RRR | Royal Air Force | ASCOT | United Kingdom | RAF HQSTC (Air Transport) |
| | RRF | Royal Air Force | KITTY | United Kingdom | RAF positioning flights |
| | SHF | Royal Air Force | VORTEX | United Kingdom | Support Helicopter Force |
| | RAX | Royal Air Freight | AIR ROYAL | United States | |
| AT | RAM | Royal Air Maroc | ROYALAIR MAROC | Morocco | |
| R0 | RPK | Royal Airlines | ROYAL PAKISTAN | Pakistan | |
| | RLM | Royal American Airways | ROYAL AMERICAN | United States | |
| V5 | RYL | Royal Aruban Airlines | ROYAL ARUBAN | Aruba | |
| | ASY | Royal Australian Air Force | AUSSIE | Australia | Used by RAAF units internationally |
| | RXP | Royal Aviation Express | ROY EXPRESS | Canada | |
| | RYB | Royal Bahrain Airlines | ROYAL BAHRAIN | Bahrain | |
| BI | RBA | Royal Brunei Airlines | BRUNEI | Brunei | |
| | KDR | Royal Daisy Airlines | DARLINES | Uganda | |
| | RGA | Royal Ghanaian Airlines | ROYAL GHANA | Ghana | |
| | ROJ | Royal Jet | ROYALJET | United Arab Emirates | |
| RJ | RJA | Royal Jordanian | JORDANIAN | Jordan | |
| | RJZ | Royal Jordanian Air Force | JORDAN AIR FORCE | Jordan | |
| RK | RCT | Skyview Airways | GREENSKY | THAILAND | 2014 |
| RK | RKH | Royal Khmer Airlines | KHMER AIR | Cambodia | |
| | RMF | Royal Malaysian Air Force | ANGKASA | Malaysia | |
| | NVY | Royal Navy | NAVY | United Kingdom | |
| | NRN | Royal Netherland Navy | NETHERLANDS NAVY | Netherlands | Koninklijke Marine |
| | NAF | Royal Netherlands Air Force | NETHERLANDS AIR FORCE | Netherlands | |
| | KIW | Royal New Zealand Air Force | KIWI | New Zealand | |
| | NOW | Royal Norwegian Air Force | NORWEGIAN | Norway | |
| | ROP | Royal Oman Police | | Oman | |
| RL | PPW | Royal Phnom Penh Airways | PHNOM-PENH AIR | Cambodia | |
| | RRA | Royal Rwanda Airlines | ROYAL RWANDA | Rwanda | |
| | RSF | Royal Saudi Air Force | ARSAF | Saudi Arabia | |
| RR | RYS | Buzz (Ryanair) | MAGIC SUN | Poland | |
| | RSN | Royal Swazi National Airways | SWAZI NATIONAL | Eswatini | |
| WR | HRH | Royal Tongan Airlines | TONGA ROYAL | Tonga | |
| | RWE | Royal West Airlines | ROYAL WEST | United States | |
| | RSB | Rubystar | RUBYSTAR | Belarus | |
| | RLH | Ruili Airlines | SENDI | China | |
| | RMG | Rumugu Air & Space Nigeria | RUMUGU AIR | Nigeria | |
| | RUR | Rusaero | | Russia | |
| | KLE | Rusaero | | Russia | Centre for Civil Aviation Services |
| | CGI | Rusair JSAC | CGI-RUSAIR | Russia | |
| | RUH | Rusich-T | | Russia | |
| | RLU | Rusline | RUSLINE AIR | Russia | |
| | MIG | Russian Aircraft Corporation-MiG | MIG AVIA | Russia | |
| | RFF | Russian Federation Air Force | RUSSIAN AIRFORCE | Russia | |
| P7 | ESL | Russian Sky Airlines | RADUGA | Russia | |
| | RUZ | Rusuertol | ROSTUERTOL | Russia | |
| 5R | RUC | Rutaca | RUTACA | Venezuela | |
| | RND | Rutland Aviation | RUTLAND | United Kingdom | |
| | RUA | Rwanda Airlines | | Rwanda | |
| | RWA | Rwanda Airways | | Rwanda | |
| WB | RWD | Rwandair Express | RWANDAIR | Rwanda | |
| | RWL | RWL Luftfahrtgesellschaft | RHEINTRAINER | Germany | |
| 7S | RYA | Ryan Air Services | RYAN AIR | United States | |
| RD | RYN | Ryan International Airlines | RYAN INTERNATIONAL | United States | defunct 2013 |
| FR | RYR | Ryanair | RYANAIR | Ireland | |
| RK | RUK | Ryanair UK | BLUEMAX | United Kingdom | |
| | RYZ | Ryazan State Air Enterprise | RYAZAN AIR | Russia | |
| | RAA | Rynes Aviation | RYNES AVIATION | United States | |
| | REV | RVL Group | ENDURANCE | United Kingdom | |
| RT | BUG | UVT Aero | | Russia | |
| | OMN | Servicios Aereos Ominia | SERVIOMNIA | Mexico | 2014 |
| | SEN | Servicios de Aviacion Sierra | SERVISIERRA | Mexico | 2014 |
| | SGC | SGC Aviation | SAINT GEORGE | Austria | 2014 |
| | SCJ | Siamjet Aviation | SIAMJET | Thailand | 2014 |
| | SIX | Sixt Rent A Car | DRIVE ORANGE | United States | 2014 |
| | SOG | Solenta Aviation Ghana | | Ghana | 2014 |
| | QSR | SR Jet | SPARKLE ROLL | China | 2014 |
| | KBN | Spiracha Aviation | KABIN | Thailand | 2014 |
| | CBN | Southern Illinois University as "Aviation Flight" | CARBONDALE | United States | Allocated in 2014 |
| | IBG | Springfield Air | ICE BRIDGE | United States | Allocated 2014 |
| | BZQ | Seneca College | STING | Canada | Allocated 2014 |
| | BVV | Sparc Avia | SPARC | Russia | |
| | SJM | Sino Jet Management | SINO SKY | China | |
| | SCH | Seychelles Airlines | OCEAN BIRD | Seychelles | |
| | BYF | San Carlos Flight Center | BAY FLIGHT | United States | |
| | SXT | Servicios de Taxi Aereos | SERTAXI | Mexico | |
| TR | TGW | Scoot | SCOOTER | Singapore | Former IATA: TZ Former ICAO: SCO; Adopted Tigerair codes after their merger |
| IJ | SJO | Spring Airlines Japan | JEY SPRING | Japan | |
| | SBD | SIBIA Aircompany Ltd | SIBIA | Russia | |
| | SHT | British Airways Shuttle | SHUTTLE | United Kingdom | |
| 6Y | ART | Smartlynx Airlines | SMART LYNX | Latvia | |
| | MYX | Smartlynx Airlines Estonia | TALLINN CAT | Estonia | |
| QS | TVS | Smartwings | SKYTRAVEL | Czech Republic | formerly named Travel Service |
| 7O | TVL | Smartwings Hungary | TRAVEL SERVICE | Hungary | formerly named Travel Service Hungary |
| 3Z | TVP | Smartwings Poland | JETTRAVEL | Poland | formerly named Travel Service Poland |
| 6D | TVQ | Smartwings Slovakia | SLOVAKTRAVEL | Slovakia | formerly named Travel Service Slovakia |
| | DES | Servicios Aereos Especializados Destina | DESTINA | Mexico | |
| | LSV | Slovenian Ministry of Defence | | Slovenia | |
| | FUF | Servicios Aereos Fun Fly | SERVIFUN | Mexico | |
| E3 | VGO | Sabaidee Airways | VIRGO | Thailand | |
| | SAQ | Safe Air Company | | Kenya | |
| | SMU | Sanborn Map Company | SPRINGER | United States | |
| | RBR | Siam Airnet | SIAM AIRNET | Thailand | |
| | SVB | Siavia | SIAVIA | Slovenia | |
| | MHQ | Skargardshavets Helikoptertjanst | HELICARE | Finland | |
| | BIS | Sky Bishek | JUMA AIR | Kyrgyzstan | |
| | SYH | Sky Handling | | Ukraine | |
| GG | KYE | Sky Lease Cargo | SKY CUBE | United States | |
| | KPM | Sky Prim Air | SKY PRIMAIR | Molodva | |
| BQ | SWU | Sky Alps | SKYALPS | Italy | |
| | BSJ | Skybus Jet | SKYBUS JET | Bahamas | |
| GW | SGR | SkyGreece Airlines | SKYGREECE | Greece | defunct |
| | USW | Special Aviation Works | AKSAR | Uzbekistan | |
| SH | SHA | Sharp Airlines | SHARP | Australia | Uses unregistered ICAO & IATA. |
| N9 | SHA | Shree Airlines | SHREEAIR | Nepal | |
| 7E | AWU | Sylt Air GmbH | SYLT-AIR | Germany | |
| | BDS | South Asian Airlines | SOUTH ASIAN | Bangladesh | |
| OL | SZB | Samoa Air | SAMOA | Samoa | |
| | BEC | State Air Company Berkut | | Kazakhstan | |
| S4 | RZO | SATA International | AIR AZORES | Portugal | |
| SA | SAA | South African Airways | SPRINGBOK | South Africa | |
| | KYD | Sky Messaging | SKYAD | South Africa | |
| | SAB | Sky Way Air | SKY WORKER | Kyrgyzstan | |
| KV | SKV | Sky Regional Airlines | MAPLE | Canada | |
| | SAC | SASCO Airlines | SASCO | Sudan | |
| | SAG | SOS Flygambulans | MEDICAL AIR | Sweden | |
| W7 | SAH | Sayakhat Airlines | SAYAKHAT | Kazakhstan | |
| NL | SAI | Shaheen Air | SHAHEEN AIR | Pakistan | |
| MM | SAM | SAM Colombia | SAM | Colombia | Sociedad Aeronáutica De Medellín |
| | SAN | Servicios Aéreos Nacionales (SAN) | AEREOS | Ecuador | defunct |
| | SAO | Sahel Aviation Service | SAVSER | Mali | |
| | ANX | Secretaria de Marina | SECRETARIA DEMARINA | Mexico | |
| | SAQ | Springbank Aviation | SPRINGBANK | Canada | |
| SK | SAS | Scandinavian Airlines | SCANDINAVIAN | Sweden, Denmark and Norway | |
| | SAV | Samal Air | | Kazakhstan | |
| | SAW | Cham Wing Airlines | SHAMWING | Syrian Arab Republic | |
| | SAX | Sabah Air | SABAH AIR | Malaysia | |
| | SAY | ScotAirways | SUCKLING | United Kingdom | |
| | SAZ | Swiss Air-Ambulance | SWISS AMBULANCE | Switzerland | |
| | SBA | SOL Linhas Aéreas | SOL | Brazil | |
| PI | SGU | Sol del Paraguay | SOLPARAGUAYO | Paraguay | |
| | SBA | STA-MALI | STA-MALI | Mali | defunct |
| | SBB | Steinman Aviation | SABER EXPRESS | United States | |
| UG | TUX | Tunisair Express | TUNEXPRESS | Tunisia | |
| | SBF | Seven Bar Flying Service | SEVENAIR | Tunisia | |
| | SBG | Sabre Incorporated | | United States | |
| S7 | SBI | S7 Airlines | SIBERIAN AIRLINES | Russia | |
| | SBL | Sobel Airlines of Ghana | SOBGHANA | Ghana | |
| Q7 | SBM | SkyBahamas | SKY BAHAMAS | Bahamas | |
| | SBO | Stabo Air | STABAIR | Zambia | |
| | SBQ | SmithKline Beecham Clinical Labs | SKIBBLE | United States | |
| | SBR | Saber Aviation | FREIGHTER | United States | |
| BB | SBS | Seaborne Airlines | SEABORNE | United States | |
| PV | SBU | St Barth Commuter | BLACK FIN | France | |
| | URJ | Star Air | STARAV | Pakistan | |
| S5 | SDG | Star Air (India) | HISTAR | India | |
| JX | SJX | Starlux Airlines | STARWALKER | Taiwan | |
| | SBZ | Scibe Airlift | SCIBE AIRLIFT | Democratic Republic of the Congo | |
| | AME | Spanish Air Force | AIRMIL | Spain | |
| | SCA | South Central Air | SOUTH CENTRAL | United States | |
| | SCC | Seacoast Airlines | SEA-COASTER | United States | |
| K5 | SQH | SeaPort Airlines | SASQUATCH | United States | Former airline: Wings of Alaska now part of SeaPort Airlines. Alternative callsign: WINGS (for VFR flights only). Former ICAO code: WAK. |
| | SCE | Scenic Airlines | SCENIC | United States | |
| | SCF | Socofer | SOCOFER | Angola | |
| | SCI | Servicios Aéreos San Cristóbal | SAN CRISTOBAL | Mexico | |
| | SCK | Sky Cam | SKYCAM | France | |
| W3 | SCL | Switfair Cargo | SWIFTAIR | Canada | |
| | SCB | Saigon Capital Aircraft Management | SAIGON | Netherlands | |
| | SCN | South American Airlines | SOUTH AMERICAN | Peru | |
| | AHI | Servicios Aéreos de Chihuahua Aerochisa | AEROCHISA | Mexico | |
| FP | AND | Servicios Aéreos de los Andes | SERVI ANDES | Peru | 2014 |
| | SCP | Scorpio Aviation | SCORPIO | Egypt | |
| | SCQ | OSM Aviation Academy | SCAVAC | Norway, Sweden and San Diego | |
| | SIC | SFS Aviation | SICHART | Thailand | |
| | SCR | Silver Cloud Air | SILVER CLOUD | Germany | |
| | SCS | South African Non Scheduled Airways | SOUTHERN CHARTERS | South Africa | |
| | SCT | SAAB-Aircraft | SAAB-CRAFT | Sweden | |
| | SCV | Servicios Aéreos Del Centro | SACSA | Mexico | |
| SY | SCX | Sun Country Airlines | SUN COUNTRY | United States | |
| | SDA | St. Andrews Airways | SAINT ANDREWS | Canada | |
| | SDB | Sukhoi Design Bureau Company | SU-CRAFT | Russia | |
| | SDC | Sunrise Airlines | SUNDANCE | United States | |
| | SDD | Skymaster Air Taxi | SKY DANCE | United States | |
| | SDE | Air Partners Corp. | STAMPEDE | Canada | |
| | SDF | Sundorph Aeronautical Corporation | SUNDORPH | United States | |
| | SDH | Servicio De Helicopteros | ARCOS | Spain | |
| | SDK | SADELCA - Sociedad Aérea Del Caquetá | SADELCA | Colombia | |
| | SDL | Skydrift | SKYDRIFT | United Kingdom | |
| | SDN | Spirit of Africa Airlines | BLUE NILE | Sudan | |
| | SDU | Sud Airlines | SUD LINES | France | |
| | SDV | Servicios Aéreos Del Vaupes | SELVA | Colombia | |
| | SDX | Servicio Tecnico Aero De Mexico | SERVICIO TECNICO | Mexico | |
| | SDZ | Sudan Pezetel for Aviation | SUDANA | Sudan | |
| | SEA | Southeast Air | SOUTHEAST AIR | United States | |
| | SEB | Servicios Aéreos Luce | SERVILUCE | Mexico | |
| | SED | Sedona Air Center | SEDONA AIR | United States | |
| | SEE | Shaheen Air Cargo | SHAHEEN CARGO | Pakistan | |
| | SEH | Sky Express | AIR CRETE | Greece | |
| SG | SEJ | Spicejet | SPICEJET | India | |
| | SEK | Skyjet | SKALA | Kazakhstan | |
| | SEL | Sentel Corporation | SENTEL | United States | |
| | SEO | Selcon Airlines | SELCON AIR | Nigeria | |
| I6 | SEQ | Sky Eyes | SKY EYES | Thailand | |
| | SES | Servicio Aéreo Saltillo | SERVISAL | Mexico | |
| EH | SET | SAETA | SAETA | Ecuador | |
| | SEV | Serair Transworld Press | CARGOPRESS | Spain | |
| | SFA | SEFA | SEFA | France | defunct - absorbed into École Nationale de l'Aviation Civile, with new ICAO code NAK |
| | SFC | Shuswap Flight Centre | SHUSWAP | Canada | |
| | SFE | Sefofane Air Charters | SEFOFANE | Botswana | Rebranded "Wilderness Air" |
| | SFF | Safewings Aviation Company | SWIFTWING | United States | |
| | SFG | Sun Freight Logistics | AERO GULF | Thailand | |
| 7G | SFJ | Star Flyer | STARFLYER | Japan | |
| | SFL | Southflight Aviation | SOUTHFLIGHT | New Zealand | |
| | SFN | Safiran Airlines | SAFIRAN | Iran | |
| | SFP | Safe Air | SAFE AIR | Pakistan | |
| FA | SFR | Safair | CARGO | South Africa | |
| | SFS | Southern Frontier Air Transport | SOUTHERN FRONTIER | Canada | |
| | SFT | Skyfreight | SKYFREIGHT | United States | |
| | SFU | Solent Flight | SAINTS | United Kingdom | |
| | SFX | S.K. Logistics | SWAMP FOX | United States | |
| | SGB | Sky King, Inc. | SONGBIRD | United States | |
| | SGC | Southern Right Air Charter | SOUTHERNRIGHT | South Africa | |
| | SGD | Sky Gate International Aviation | AIR BISHKEK | Kyrgyzstan | |
| | SGF | STAC Swiss Government Flights | STAC | Switzerland | |
| | SGH | Servisair | SERVISAIR | United Kingdom | |
| | SGI | Servicios Aéreos Agrícolas | SERAGRI | Chile | |
| | SGK | Skyward Aviation | SKYWARD | Canada | |
| | SGM | Sky Aircraft Service | SIGMA | Netherlands | |
| | SGN | Siam GA | SIAM | Thailand | |
| | SGP | Sagolair Transportes Ejecutivos | SAGOLAIR | Spain | |
| | SGS | Saskatchewan Government Executive Air Service | SASKATCHEWAN | Canada | |
| | SGT | Skygate | SKYGATE | Netherlands | |
| | SGU | Samgau | RAUSHAN | Kazakhstan | |
| | SGX | Saga Airlines | | Turkey | |
| N5 | SGY | Skagway Air Service | SKAGWAY AIR | United States | |
| | SHB | Shabair | SHABAIR | Democratic Republic of the Congo | |
| | SHC | Sky Harbor Air Service | SKY HARBOR CHEYENNE | United States | |
| | SHD | Sahara Airlines | | Algeria | |
| | SHE | Shell Aircraft | SHELL | United Kingdom | |
| | SHG | Shoprite Group | SHOP AIR | United Kingdom | |
| | SHJ | Sharjah Ruler's Flight | SHARJAH | United Arab Emirates | |
| | SHK | Shorouk Air | | Egypt | |
| | SHL | Samson Aviation | SAMSON | United Kingdom | |
| | SHM | Sheltam Aviation | SHELTAM | South Africa | |
| | SHN | Shaheen Airport Services | SUGAR ALFA | Pakistan | |
| | SHO | Sheremetyevo-Cargo | | Russia | |
| | SHP | Service Aerien Francais | SAF | France | |
| | SHQ | Shanghai Airlines Cargo | SHANGHAI CARGO | China | |
| | SHR | Shooter Air Courier | SHOOTER | Canada | |
| | SHS | Shura Air Transport Services | SHURA AIR | Ethiopia | |
| HZ | SHU | Sakhalinskie Aviatrassy (SAT) | SATAIR | Russia | |
| SP | SAT | SATA Air Acores | SATA | Portugal | |
| 8S | | Scorpio Aviation | | | |
| | SHV | Shavano Air | SHAVANO | United States | |
| | SHW | Shawnee Airline | SHAWNEE | United States | Air South |
| | SHX | Slim Aviation Services | SLIM AIR | Nigeria | |
| ZY | SHY | Sky Airlines | ANTALYA BIRD | Turkey | |
| SQ | SIA | Singapore Airlines | SINGAPORE | Singapore | |
| 5M | SIB | Sibaviatrans | SIBAVIA | Russia | |
| | SIE | Sierra Express | SEREX | United States | |
| SI | SIH | Skynet Airlines | BLUEJET | Ireland | 2001–2004 |
| | SIJ | Seco International | | Japan | |
| 3M | SIL | Silver Airways | SILVER WINGS | United States | |
| | SIL | Servicios Aeronáuticos Integrales | SERVICIOS INTEGRALES | Mexico | |
| | SIM | Star Air | | Sierra Leone | |
| | SIO | Sirio (airline) | SIRIO | Italy | |
| | SIR | Salair | SALAIR | United States | |
| | SIS | Saber Airlines | | Egypt | |
| XS | SIT | SITA | | Belgium | |
| | SIV | Slovenian Armed Forces | SLOVENIAN | Slovenia | |
| | SIW | Sirio Executive | SIRIO EXECUTIVE | Italy | |
| | SJA | Servicios Aéreos Especiales De Jalisco | SERVICIOJAL | Mexico | |
| | SJC | Servicios Ejecutivos Continental | SERVIEJECUTIVO | Mexico | |
| | SJE | Sunair 2001 | SUNBIZ | South Africa | |
| | SJJ | Spirit Aviation | SPIRIT JET | United States | |
| | SJL | Servicios Especiales Del Pacifico Jalisco | SERVICIOS JALISCO | Mexico | |
| | SJT | Swiss Jet | SWISS JET | Switzerland | |
| | SJY | Sriwijaya Air | SRIWIJAYA | Indonesia | |
| ZS | SMY | Sama Airlines | NAJIM | Saudi Arabia | |
| | ALC | Southern Jersey Airways, Inc. | ACOM | United States | |
| | SPS | Spark Shuttle | Spark Shuttle | United States | |
| | SPT | Speed Aviation | SPEED AVIATION | Bangladesh | |
| | SPU | Southeast Airmotive | SPUTTER | United States | |
| | SPV | Servicios Privados De Aviación | SERVICIOS PRIVADOS | Mexico | |
| | SPW | Speedwings | SPEEDWING | Switzerland | |
| | SPX | Spark Express (Glow) | Glow|United States | |
| | SQA | Slovak National Aeroclub | SLOVAK AEROCLUB | Slovakia | |
| SQ | SQC | Singapore Airlines Cargo | SINGCARGO | Singapore | |
| | SQF | Slovak Air Force | SLOVAK AIRFORCE | Slovakia | |
| | SQL | Servicos De Alquiler | ALQUILER | Mexico | |
| | SRA | Sair Aviation | SAIR | Canada | |
| | SRC | Searca | SEARCA | Colombia | |
| FT | SRH | Siem Reap Airways | SIEMREAP AIR | Cambodia | |
| SX | SRK | Sky Work Airlines | SKYFOX | Switzerland | |
| SM | SRL | Swedline Express | Starline | Sweden | Ceased operations 2006 |
| | SRL | Servicios Aeronáuticos Aero Personal | SERVICIOS PERSONAL | Mexico | |
| | SRN | Sirair | SIRAIR | Russia | |
| P8 | SRN | SprintAir | SPRINTAIR | Poland | |
| | SRO | Servicios Aéreos Ejecutivos Saereo | SAEREO | Ecuador | |
| | SRQ | South East Asian Airlines | SEAIR | Philippines | Rebranded to Tiger Airways Philippines |
| | SRS | Selkirk Remote Sensing | PHOTO CHARLIE | Canada | |
| | SRU | Star Up | STAR-UP | Peru | |
| | SRW | Sarit Airlines | SARIA | Sudan | |
| | SRX | Sierra Expressway Airlines | SIERRA EX | United States | |
| | SRZ | Strato Air Services | STRATO | South Africa | |
| | SSB | Sasair | SASIR | Canada | |
| | SSC | Southern Seaplane | SOUTHERN SKIES | United States | |
| | SSD | Star Service International | STAR SERVICE | France | |
| | SSE | Servicios Aéreos Sunset | SUNSET | Mexico | |
| D2 | SSF | Severstal Air Company | SEVERSTAL | Russia | |
| | SSG | Slovak Government Flying Service | SLOVAK GOVERNMENT | Slovakia | |
| VD | BBB | SwedJet Airways | BLACKBIRD | Sweden | |
| | SSK | Skystar International | SKYSTAR | United States | |
| | SSO | Special Scope Limited | DOPE | United Kingdom | |
| | SSP | Starspeed | STARSPEED | United Kingdom | |
| QF | SSQ | Sunstate Airlines | SUNSTATE | Australia | Uses IATA of parent QANTAS. |
| | SSR | Sardinian Sky Service | SARDINIAN | Italy | |
| | SSS | SAESA | SAESA | Spain | |
| | SST | Sunwest Airlines | SUNFLIGHT | Canada | |
| | SSU | SASCA | SASCA | Venezuela | |
| 5G | SSV | Skyservice Airlines | SKYTOUR | Canada | defunct |
| | SSW | Streamline Aviation | STREAMLINE | United Kingdom | |
| | SSY | Sky Aviation | SIERRA SKY | Sierra Leone | |
| | SSZ | Specsavers Aviation | SPECSAVERS | United Kingdom | |
| | STA | Star Aviation | STAR | United Kingdom | |
| | STB | Status-Alpha Airline | STATUS-ALPHA | Ukraine | |
| | STC | Stadium City Limited | STADIUM | United Kingdom | |
| | STD | Servicios De Aerotransportacion De Aguascalientes | AERO AGUASCALINETES | Mexico | |
| | STE | Semitool Europe | SEMITRANS | United Kingdom | |
| | STF | SFT-Sudanese Flight | | Sudan | |
| | STG | Sedalia, Marshall, Boonville Stage Line | STAGE | United States | |
| | STH | South-Airlines | | Armenia | |
| | STI | Sontair | SONTAIR | Canada | |
| | STJ | Sella Aviation | STELLAVIA | Netherlands | |
| RE | STK | Stobart Air | STOBART | Ireland | |
| | STL | Stapleford Flight Centre | STAPLEFORD | United Kingdom | |
| | STO | Streamline Ops | SLOPS | Russia | |
| | STQ | Star Air | STERA | Indonesia | |
| FS | STU | Servicios de Transportes Aéreos Fueguinos | FUEGUINO | Argentina | ICAO and call sign not current |
| | STU | Star African Air | STARSOM | Somali Republic | |
| | SUU | Star West Aviation | SUNSTAR | United States | |
| | STV | Saturn Aviation | SATURN | United States | |
| | STW | South West Air Corporation | SIERRA WHISKEY | Philippines | |
| | STX | Stars Away Aviation | STARSAWAY | South Africa | |
| | STY | Styrian Airways | STYRIAN | Austria | |
| | SUA | Silesia Air | AIR SILESIA | Czech Republic | |
| | SUB | Suburban Air Freight | SUB AIR | United States | |
| SD | SUD | Sudan Airways | SUDANAIR | Sudan | |
| PI | SUF | Sun Air (Fiji) | SUNFLOWER | Fiji | |
| LW | FDY | Sun Air International | FRIENDLY | United States | |
| | SUG | Sunu Air | SUNU AIR | Senegal | |
| | SUH | Sun Light | LIGHT AIR | Kyrgyzstan | |
| | SUI | Swiss Air Force | SWISS AIR FORCE | Switzerland | |
| | SUK | Superior Aviation Services | SKYCARGO | Kenya | |
| | SUM | State Unitary Air Enterprise | SUMES | Russia | |
| | SUR | Sun Air | | Egypt | |
| EZ | SUS | Sun Air of Scandinavia | SUNSCAN | Denmark | |
| | URF | Surf Air | SURF AIR | United States | |
| | SUT | Sistemas Aeronauuticos 2000 | SISTEMAS AERONAUTICOS | Mexico | |
| | SUV | Sundance Air | DANCEAIR | Venezuela | |
| SV | SVA | Saudia | SAUDIA | Saudi Arabia | |
| | SVD | St. Vincent Grenadines Air (1990) | GRENADINES | Saint Vincent and the Grenadines | |
| | SVF | Swedish Armed Forces | SWEDEFORCE | Sweden | |
| | AWJ | Sahel Airlines | SAHEL AIRLINES | Niger | |
| | SVH | Sterling Helicopters | SILVER | United Kingdom | |
| | SVI | Servicios De Transporte Aéreo | SETRA | Mexico | |
| | SVJ | Silver Air | | Djibouti | |
| | SVL | Sevastopol-Avia | SEVAVIA | Ukraine | |
| | SVN | Savanair (Angola) | SAVANAIR | Angola | |
| | SVO | Servicios Aeronáuticos De Oriente | SERVIORIENTE | Mexico | |
| | SVS | Servicios Aéreos Saar | AEREOS SAAR | Mexico | |
| | SVT | Seven Four Eight Air Services | SIERRA SERVICES | Luxembourg | |
| | SVX | Security Aviation | SECURITY AIR | United States | |
| WN | SWA | Southwest Airlines | SOUTHWEST | United States | |
| | SWB | Swissboogie Parapro | SWISSBOOGIE | Switzerland | |
| | SWC | South West Air | SAINT CLAIR | Canada | |
| A4 | SWD | Southern Winds Airlines | SOUTHERN WINDS | Argentina | |
| | SWE | Swedeways | SWEDELINE | Sweden | |
| | | Spurling Aviation | AIR SEATTLE | United States | Code was ASL |
| WG | SWG | Sunwing Airlines | SUNWING | Canada | |
| | SWI | Sunworld Airlines | SUNWORLD | United States | |
| | SWJ | StatesWest Airlines | STATES | United States | |
| | SWO | Surinam International Victory Airline | SIVA | Suriname | defunct |
| | SWP | Star Work Sky | STAR WORK | Italy | |
| WQ | SWQ | Swift Air (Interstate Equipment Leasing) | SWIFTFLIGHT | United States | |
| LX | SWR | Swiss International Air Lines | SWISS | Switzerland | |
| SR | SWR | Swissair | SWISSAIR | Switzerland | defunct |
| SR | SDR | Sundair | SUNDAIR | Germany | |
| | SWS | Sunwest Aviation (Lindquist Investment) | SUNNY WEST | United States | |
| | SWT | Swiftair | SWIFT | Spain | |
| LZ | SWU | Swiss Global Air Lines | EUROSWISS | Switzerland | |
| WV | SWV | Swe Fly | FLYING SWEDE | Sweden | |
| S8 | SWW | Shovkoviy Shlyah | WAY AERO | Ukraine | |
| Q4 | SWX | Swazi Express Airways | SWAZI EXPRESS | Eswatini | |
| WO | WSW | Swoop | SWOOP | Canada | |
| | SWY | Sky Jet | SWISSLINK | Switzerland | |
| | SWZ | Servair, Private Charter | SWISSBIRD | Switzerland | Code re-allocated |
| S8 | SWZ | Skywise Airline | SKYWISE | South Africa | |
| | SXA | Southern Cross Aviation | FERRY | United States | |
| | SXC | Sky Exec Aviation Services | SKY EXEC | Nigeria | |
| | SXE | Southeast Express Airlines | DOGWOOD EXPRESS | United States | |
| | SXM | Servicios Aéreos Especializados Mexicanos | SERVIMEX | Mexico | |
| XQ | SXS | SunExpress | SUNEXPRESS | Turkey | |
| | SXT | Servicios De Taxi Aéreo | SERTA | Mexico | |
| | SXX | Satellite Aero | SATELLITE EXPRESS | United States | |
| | SXY | Safari Express Cargo | SAFARI EXPRESS | Kenya | |
| | SYA | Skyways | LINEAS CARDINAL | Argentina | |
| | SYC | Systec 2000 | SYSTEC | United States | |
| | SYE | Sheba Aviation | | Yemen | |
| | SYF | Sky One Express Airlines | SKY FIRST | United States | |
| | SYG | Synergy Aviation | SYNERGY | United Kingdom | |
| | SYI | Sonalysts | | United States | |
| | SYJ | Slate Falls Airways | | Canada | |
| | SYK | Satsair | AEROCAB | United States | (J and A Properties) |
| | SYN | Syncrude Canada | SYNCRUDE | Canada | |
| RB | SYR | Syrian Arab Airlines | SYRIANAIR | Syrian Arab Republic | |
| | SYS | Shawbury Flying Training Unit | SHAWBURY | United Kingdom | |
| | SYV | Special Aviation Systems | SPECIAL SYSTEM | United States | |
| AL | SYX | Skywalk Airlines | SKYWAY-EX | United States | (Astral Aviation) |
| ZP | AZQ | Silk Way Airlines | SILK LINE | Azerbaijan | |
| 7L | AZG | Silk Way West Airlines | SILK WEST | Azerbaijan | |
| | SYY | South African Historic Flight | SKY COACH | South Africa | |
| | SZT | Servicios Aeronáuticos Z | AERO ZEE | Mexico | |
| | BHV | Specavia Air Company | AVIASPEC | Russia | |
| | BLY | Starair | BLARNEY | Ireland | |
| | BNC | Sundance Air | BARNACLE AIR | United States | |
| E5 | BRZ | Samara Airlines | BERYOZA | Russia | defunct |
| E5 | RBG | Air Arabia Egypt | ARABIA EGYPT | Egypt | |
| | CBN | Swedish Civil Aviation Administration | CALIBRATION | Sweden | |
| SC | CDG | Shandong Airlines | SHANDONG | China | |
| | CDS | Spectrem Air | SPECDAS | South Africa | |
| | CEE | Servicios Aéreos Centrales | CENTRA AEREOS | Mexico | |
| | CFL | Swedish Airlines | SWEDISH | Sweden | |
| | CGL | Seagle Air | SEAGLE | Slovakia | |
| | CIG | Sirius-Aero | SIRIUS AERO | Russia | |
| | CNK | Sunwest Home Aviation | CHINOOK | Canada | |
| SK | CNO | SAS Braathens | SCANOR | Norway | |
| 9C | CQH | Spring Airlines | AIR SPRING | China | |
| 3U | CSC | Sichuan Airlines | SI CHUAN | China | |
| FM | CSH | Shanghai Airlines | SHANGHAI AIR | China | Part of China Eastern Airlines |
| | CSY | Shuangyang General Aviation | SHUANGYANG | China | |
| ZH | CSZ | Shenzhen Airlines | SHENZHEN AIR | China | |
| 8C | CXI | Corendon Airlines Europe | TOURIST | Malta | |
| | DKT | Sioux Falls Aviation | DAKOTA | United States | |
| | DKY | Servicios Aéreos Elite | DAKOY | Spain | |
| | DNI | Servicios Aéreos Denim | AERO DENIM | Mexico | |
| | EAB | Swiss Eagle | SWISS EAGLE | Switzerland | |
| | EAN | Skypower Express Airways | NIGERIA EXPRESS | Nigeria | Express Airways Nigeria |
| | ENR | Scenic Air | | Namibia | |
| 7L | ERO | Sun D'Or | ECHO ROMEO | Israel | |
| NE | ESK | SkyEurope | RELAX | Slovakia | defunct |
| CQ | EXL | Sunshine Express Airlines | | Australia | |
| | EXY | South African Express | EXPRESSWAYS | South Africa | |
| | FFD | Stuttgarter Flugdienst | FIRST FLIGHT | Germany | |
| | FFH | Shalom Air Services | PEACE AIR | Nigeria | |
| | FJE | Silverjet | ENVOY | United Kingdom | |
| | FLH | Sky Bus | MILE HIGH | United States | |
| | GAD | South Coast Aviation | SOUTHCOAST | United Kingdom | |
| | GDE | Servicios Aéreos Gadel | GADEL | Mexico | |
| | GDG | S.P. Aviation | GOLDEN GATE | United States | |
| | GIK | Seba Airlines | SEBA | Guinea | |
| | GNA | Servicios Aéreos Gana | SERVIGANA | Mexico | |
| | GSW | Sky Wings Airlines | | Greece | |
| | GXL | Star XL German Airlines | STARDUST | Germany | |
| | HAU | Skyhaul | SKYHAUL | Japan | |
| | HIP | Starship | STARSA | Mexico | |
| | HJE | Servicios Ejecutivos Gosa | GOSA | Mexico | |
| SO | HKA | Superior Aviation | SPEND AIR | United States | |
| | HLO | Samaritan Air Service | HALO | Canada | |
| KI | SJB | SKS Airways | SOUTHER TIGER | Malaysia | Operates scheduled flights to outlying islands from Subang Airport to Redang and Tioman. |
| | HRI | Skyraidybos Mokymo Centras | HELIRIM | Lithuania | |
| | HSK | Sky Europe Airlines | MATRA | Slovakia | |
| | HSV | Svenska Direktflyg | HIGHSWEDE | Sweden | |
| | HSY | Sky Helicopteros | HELISKY | Spain | |
| TE | IGA | Skytaxi | IGUANA | Poland | |
| | IJS | Silvair | | United States | |
| | ILS | Servicios Aéreos Ilsa | SERVICIOS ILSA | Mexico | |
| | INK | Sincom-Avia | SINCOM AVIA | Ukraine | |
| | IRV | Safat Airlines | SAFAT AIR | Iran | |
| | IRZ | Saha Airlines Services | SAHA | Iran | |
| | JAM | Sunline Express | SUNTRACK | Kenya | |
| | JCM | Secure Air Charter | SECUREAIR | United States | |
| | JIM | Sark International Airways | SARK | United Kingdom | |
| JK | JKK | Spanair | SPANAIR | Spain | defunct |
| | KKS | Salem | KOKSHE | Kazakhstan | |
| | KOP | Servicios Aéreos Copters | COPTERS | Chile | |
| | KSP | Servicios Aéreos Expecializados En Transportes Petroleros | SAEP | Colombia | |
| | KYR | Sky Aeronautical Services | SKY AERONAUTICAL | Mexico | |
| | LGU | Servicios Aéreos Ejecutivos De La Laguna | LAGUNA | Mexico | |
| | LLA | Servico Leo Lopex | LEO LOPOZ | Mexico | |
| | LLS | Servicios Aéreos Estrella | SERVIESTRELLA | Mexico | |
| | LMG | South African Air Force | SOUTH AFRICAN | South Africa | |
| | LMO | Sky One Holdings as Privaira | SKY HOLDINGS | United States | Callsign and company name changed from Sky Limo Corporation "SKY LIMO" in 2015. |
| RZ* | LRS | Sansa | | Costa Rica | |
| | LSP | Spectrum Aviation Incorporated | AIR TONY | United Kingdom | |
| | MCG | SOS Helikoptern Gotland | MEDICOPTER | Sweden | |
| | MDT | Sundt Air | MIDNIGHT | Norway | |
| | MLO | Servicios Aéreos Milenio | MILENIO | Mexico | |
| | MMS | SAAD (A320) Limited | MUSAAD AIR | Cayman Islands | |
| | MRI | Servicios Aéreos Moritani | MORITANI | Mexico | |
| 2G* | MRR | San Juan Airlines | MARINER | United States | |
| | MSG | Servico Aéreo Regional | SAR-REGIONAL | Mozambique | |
| | MSP | Servicio De Vigilancia Aérea Del Ministerio De Seguridad Pública | SEGURIDAD | Costa Rica | |
| | MTG | Servicios Aéreos MTT | | Mexico | |
| 1Z | APD | Sabre Pacific | | Australia | |
| 1S | | Sabre | | United States | |
| 1I | | Sierra Nevada Airlines | | United States | |
| 1H | | Siren-Travel | | Russia | |
| 1Q | | Sirena | | Russia | |
| | SBW | Snowbird Airlines | SNOWMAN | Finland | |
| 1K | | Southern Cross Distribution | | Australia | |
| 1K | | Sutra | | United States | |
| 2C | | SNCF | | France | |
| 2S | | Star Equatorial Airlines | | Guinea | |
| | NAD | Seulawah Nad Air | SEULAWAH | Indonesia | |
| | NAZ | Servicios Aéreos del Nazas S.A. de C.V. | NAZAS | Mexico | |
| | NCS | Simpson Air Ltd | COMMUTER-CANADA | Canada | |
| NK | NKS | Spirit Airlines | SPIRIT WINGS | United States | |
| | NON | Servicios Aéreos Latinoamericanos | SERVICIOS LATINO | Mexico | |
| | NRZ | Servicios Aéreos Monarrez | MONARREZ | Mexico | |
| | NSC | Societe De Transport Aerien De Mauritanie | TRANS-SOCIETE | Mauritania | |
| | NSE | SATENA | SATENA | Colombia | |
| | NTB | Servicios Aéreos Del Norte | SERVINORTE | Mexico | |
| | NTG | Servicios Integrales De Aviación | INTEGRALES | Mexico | |
| S0 | OKS | Slok Air Gambia | SLOK GAMBIA | Gambia | |
| | OKT | Soko Aviation | SOKO AIR | Spain | |
| | OLC | Solar Cargo | SOLARCARGO | Venezuela | |
| | OLO | Soloflight | SOLO | United Kingdom | |
| | ONG | Sonnig SA | SONNIG | Switzerland | |
| SO | OSL | Sosoliso Airlines | SOSOLISO | Nigeria | |
| | OSS | Servicios Aéreos Noticiosos | NOTICIOSOS | Mexico | |
| | OTL | South Airlines | SOUTHLINE | Ukraine | |
| VA | VOZ | Virgin Australia Regional Airlines | VELOCITY | Australia | Operated under Virgin Australia |
| | PIV | Sokol | AEROSOKOL | Russia | |
| | PLT | South Carolina Aeronautics Commission | PALMETTO | United States | |
| | PMR | Servicios Aéreos Premier | SERVICIOS PREMIER | Mexico | |
| | PNS | Survey Udara (Penas) | PENAS | Indonesia | |
| | POB | Servicios Aéreos Poblanos | POBLANOS | Mexico | |
| | PSV | Servicios Aéreos Profesionales | PROSERVICIOS | Dominican Republic | |
| | PTM | Southeastern Airways | POSTMAN | United States | |
| | PUR | Spurwing Airlines | SPURWING | South Africa | |
| 1I | PZR | Sky Trek International Airlines | PHAZER | United States | |
| | RBW | Shandong Airlines Rainbow Jet | CAI HONG | China | |
| | REJ | SA Airlink Regional | REGIONAL LINK | South Africa | |
| | RER | Servicio Aéreo Regional Regair | REGAIR | Ecuador | |
| | RFT | Scoala Superioara De Aviatie Civila | ROMANIAN ACADEMY | Romania | |
| | RGC | Servicios Aéreos Regiomontanos | REGIOMONTANO | Mexico | |
| | RLS | S-Air | S-AIRLINES | Russia | |
| | RMP | Servicios De Rampa Y Mostrador | SERAMSA | Mexico | |
| | RSE | SNAS Aviation | RED SEA | Saudi Arabia | |
| SX | SKB | Skybus Airlines | SKYBUS | United States | defunct |
| | SKC | Skymaster Airlines | SKYMASTER AIR | Brazil | |
| | SKD | Sky Harbor Air Service | SKY DAWG | United States | |
| | SKE | Sky Tours | SKYISLE | United States | |
| | AZG | Sakaviaservice | SAKSERVICE | Georgia | Defunct |
| | SKF | Skycraft | SKYCRAFT | United States | |
| | SKG | Skycraft Air Transport | SKYCRAFT-CANADA | Canada | |
| RU | SKI | SkyKing Turks and Caicos Airways | SKYKING | Turks and Caicos Islands | IATA was QW |
| | SKK | Skylink Aviation | SKYLINK | Canada | |
| | SKL | Skycharter (Malton) | SKYCHARTER | Canada | |
| | SKN | Skyline Aviation Services | SKYLINER | United States | |
| | SKO | Scottish Airways Flyers | SKYWORK | United Kingdom | |
| | SKR | Skyscapes Air Charters | SKYSCAPES | South Africa | |
| | SKS | Sky Service | SKY SERVICE | Belgium | Callsign re-allocated |
| | SKS | Sky Link Aviation | | Pakistan | |
| S3 | BBR | Santa Barbara Airlines | SANTA BARBARA | Venezuela | |
| XT | SKT | SkyStar Airways | SKY YOU | Thailand | |
| H2 | SKU | Sky Airline | AEROSKY | Chile | |
| OO | SKW | SkyWest Airlines | SKYWEST | United States | |
| JZ | SKX | Skyways Express | SKY EXPRESS | Sweden | Ceased operations 2012; Operations continue as Avia Express |
| BC | SKY | Skymark Airlines | SKYMARK | Japan | |
| | SKZ | Skyway Enterprises | SKYWAY-INC | United States | |
| LJ | SLA | Sierra National Airlines | SELAIR | Sierra Leone | |
| | SLB | Slok Air | SLOK AIR | Nigeria | |
| | SLD | Silver Air | SILVERLINE | Czech Republic | |
| | SLE | Streamline | SLIPSTREAM | South Africa | |
| | SLF | Starfly | ELISTARFLY | Italy | |
| | SLG | Saskatchewan Government | LIFEGUARD | Canada | Air Ambulance Service |
| | SLH | Silverhawk Aviation | SILVERHAWK | United States | |
| | AGE | Servicios Aéreos de Los Ángeles | AEROANGEL | Mexico | |
| MI | SLK | SilkAir | SILKAIR | Singapore | Merged with Singapore Airlines |
| 6Q | SLL | Slovak Airlines | SLOV LINE | Slovakia | |
| PY | SLM | Surinam Airways | SURINAM | Suriname | |
| | SLN | Sloane Aviation | SLOANE | United Kingdom | |
| | SLP | Salpa Aviation | SALPA | Sudan | |
| | SLS | Servicios Aéreos Slainte | SERVICIOS SLAINTE | Mexico | |
| | SLV | Stella Aviation | AVISTELLA | Mauritania | |
| | SLW | Salama Airlines Nigeria | SALMA AIR | Nigeria | |
| | SLX | Sete Linhas Aéreas | SETE | Brazil | |
| | SLY | Sky Line for Air Services | SKYCO | Sudan | |
| | SLZ | Super Luza | LUZA | Angola | |
| | SMA | SMA Airlines | SESAME | Nigeria | |
| | SMC | Sabang Merauke Raya Air Charter | SAMER | Indonesia | |
| | SMD | Servicios Aéreos La Marquesa | SERVICIOS MARQUESA | Mexico | |
| 8D | | Servant Air | | United States | |
| | SME | Semos | SEMICH | Kazakhstan | |
| | SMF | Smalandsflyg | GORDON | Sweden | |
| | SMH | Smithair | SMITHAIR | United States | |
| | SMK | Semeyavia | ERTIS | Kazakhstan | |
| | SML | Smith Air (1976) | SMITH AIR | Canada | |
| | SMM | Summit Air | SUMMIT | Canada | |
| | SMQ | Samar Air | SAMAR AIR | Tajikistan | |
| | SMR | Somon Air | SOMON AIR | Tajikistan | |
| | SMT | Skyline | SKYLIMIT | Nigeria | |
| | AOS | Servicios Aéreos Del Sol, S.A. de C.V. | AEROSOL | Mexico | |
| | SNA | Senator Aviation Charter | SENATOR | Germany | |
| NB | SNB | Sterling Airlines | STERLING | Denmark | |
| | SNE | Servicios Aéreos De Nicaragua (SANSA) | SANSA | Nicaragua | |
| | SNF | Shans Air | SHANS AIR | Russia | |
| | SNH | Senair Services | SENSERVICE | Senegal | |
| | SNI | Savanah Airlines | SAVANAHLINE | Nigeria | |
| 6J | SNJ | Solaseed Air | NEWSKY | Japan | |
| | SNK | Southeast Airlines (Sun Jet International) | SUN KING | United States | |
| | SNL | Soonair Lines | SOONAIR | United States | |
| | SNM | Servizi Aerei | SERVIZI AEREI | Italy | |
| | SNP | Sun Pacific International | SUN PACIFIC | United States | |
| | SNQ | Sun Quest Executive Air Charter | EXECU-QUEST | United States | |
| | SNS | Societe Centrafricaine De Transport Aerien | | Central African Republic | |
| | SNT | Suncoast Aviation | SUNCOAST | United States | |
| | SNU | Snunit Aviation | | Israel | |
| | SNV | Sudanese States Aviation | SUDANESE | Sudan | |
| | SNW | Sun West Airlines | SUN WEST | United States | |
| | SNX | Sun Air Aviation Services | SUNEX | Canada | |
| | SOB | Stabo Freight | STABO | Zambia | |
| | SOC | Southern Cargo Air Lines | | Russia | |
| | SOH | Southern Ohio Aviation Sales | SOUTHERN OHIO | United States | |
| | SOI | Southern Aviation | SOAVAIR | Zambia | |
| IE | SOL | Solomon Airlines | SOLOMON | Solomon Islands | |
| | SOM | Somali Airlines | SOMALAIR | Somali Republic | |
| | SON | Sunshine Air Tours | SUNSHINE TOURS | United States | |
| | SOO | Southern Air | SOUTHERN AIR | United States | |
| | SOP | Solinair | SOLINAIR | Slovenia | |
| | SOR | Sonair Servico Aéreo | SONAIR | Angola | |
| | SOT | Southeast Correct Craft | SOUTH COURIER | United States | |
| 9X | SOU | Southern Airways | SOUTHERN EXPRESS | United States | |
| 6W | SOV | Saratov Airlines Joint Stock Company | SARATOV AIR | Russia | |
| | SOW | Sowind Air | SOWIND | Canada | Defunct - code reallocated |
| | SOW | White Sparrow GmbH | SPARROW | Austria | |
| | SOX | Solid Air | SOLIDAIR | Netherlands | |
| HZ | SOZ | Sat Airlines | SATCO | Kazakhstan | |
| | SPA | Sierra Pacific Airlines | SIERRA PACIFIC | United States | |
| | SPB | Springbok Classic Air | SPRING CLASSIC | South Africa | |
| | SPC | Spark Air Cargo | Spark Cargo | United States | |
| | SPE | Sprague Electric Company | SPRAGUE | United States | |
| | SPF | Space World Airline | SPACE WORLD | Nigeria | |
| | SPG | Springdale Air Service | SPRING AIR | United States | |
| | SPH | Sapphire Executive Air | SAPPHIRE-CHARTER | South Africa | |
| | SPI | South Pacific Island Airways | SOUTH PACIFIC | United States | |
| | SPK | Spark Airlines | SPARK | United States | |
| | SPL | Servicios Corporativos Aéreos De La Laguna | CORPORATIVOS LAGUNA | Mexico | |
| | SPN | Skorpion Air | AIR SKORPIO | Bulgaria | |
| | SPP | Sapphire Aviation | SAPPHIRE | United States | |
| | SPQ | Servicios Aéreos Palenque | SERVICOS PALENQUE | Mexico | |
| | TBS | Servicios Aéreos Tribasa | TRIBASA | Mexico | |
| S5 | TCF | Shuttle America | MERCURY | United States | |
| | SVV | SALTAVIATION | SALT | Poland | |
| | TGT | SAAB Nyge Aero | TARGET | Sweden | |
| | THB | Spark Air | THAI SABAI | Thailand | |
| | TIH | S C Ion Tiriac | TIRIAC AIR | Romania | |
| | TRL | Starlite Aviation | STARSTREAM | South Africa | |
| | TRN | Servicios Aéreos Corporativos | AEROTRON | Mauritania | |
| | TTM | Societe Tout Transport Mauritanien | TOUT-AIR | Mauritania | |
| | TZU | Servicios Aéreos Tamazula | TAMAZULA | Mexico | |
| | UGP | Shar Ink | SHARINK | Russia | |
| | UKU | Second Sverdlovsk Air Enterprise | PYSHMA | Russia | |
| | UNT | Servicios Aéreos Universitarios | UNIVERSITARIO | Mexico | |
| | USK | Skif-Air | SKIF-AIR | Ukraine | |
| | USN | Smarkand Aero Servise | SAMAS | Uzbekistan | |
| | UZS | Samarkand Airways | SOGDIANA | Uzbekistan | |
| | VDO | Servicios Aéreos Avandaro | AVANDARO | Mexico | |
| | VGS | Stichting Vliegschool 16Hoven | SMART | Netherlands | |
| | VRB | Silverback Cargo Freighters | SILVERBACK | Rwanda | |
| | VRS | Sirvair | VAIRSA | Mexico | |
| DV | VSV | Scat Air | VLASTA | Kazakhstan | |
| | VXN | Sunset Aviation | VIXEN | United States | |
| | TWY | Sunset Aviation, LLC | TWILIGHT | United States | dba Solairus Aviation |
| | WCC | Sport Air Travel | WEST COAST | United States | |
| | WFC | Swift Copters | SWIFTCOPTERS | Switzerland | |
| | WLK | Skyrover CC | SKYWATCH | South Africa | |
| | XLK | Safarilink Aviation | SAFARILINK | Kenya | |
| | XMX | SENEAM | SENEAM | Mexico | |
| | XPG | Southport Air Service | | United States | |
| | XSA | Spectrum Air Service | | United States | |
| | XSN | Stephenville Aviation Services | | Canada | |
| | XTA | Servicios Aéreos Textra | TEXTRA | Mexico | |
| | XTR | Sector Airlines | EXTER | Canada | |
| | XXS | Skyplan Services | | Canada | |
| | YBE | Stewart Aviation Services | YELLOW BIRD | United States | |
| R1 | | Sirin | | | |
| | SXN | SaxonAir | SAXONAIR | United Kingdom | |
| O3 | CSS | SF Airlines | SHUN FENG | China | |
| | SAF | Singapore Air Force | SINGA | Singapore | |
| | KFE | SkyFirst LTD | SKYFIRST | Malta | 2012 |
| PQ | SQP | SkyUp | SKYUP | Ukraine | |
| U5 | | SkyUp MT | | Malta | |
| S5 | LLC | Small Planet Airlines | SMALL PLANET | Lithuania | defunct |
| P7 | LLP | Small Planet Airlines | SKYPOL | Poland | defunct |
| P2 | LLI | Small Planet Airlines | AURIGA | Italy | defunct |
| 5P | LLX | Small Planet Airlines | GERMANJET | Germany | defunct |
| UL | ALK | SriLankan Airlines | SRILANKAN | Sri Lanka | |
| DJ | SRR | Star Air | WHITESTAR | Denmark | |
| V9 | HCW | Star1 Airlines | STAR1 | Lithuania | defunct |
| Q4 | TLK | Starlink Aviation | STARLINK | Canada | |
| | UFA | State Flight Academy of Ukraine | FLIGHT ACADEMY | Ukraine | |
| | CDL | Sunbird Airlines | CAROLINA | United States | |
| XG | SXD | Sunexpress Deutschland | SUNRISE | Germany |
| SO | AAS | Sunshine Airlines | | | defunct |
| | RZ | Superna Airlines | YANGTZE RIVER | China | |
| TC | ATC | Air Tanzania Company Limited | TANZANIA | Tanzania | |
| 9L | TOW | AirTanker Services | TOWLINE | United Kingdom | |
| DG | SRQ | Cebgo | BLUE JAY | Philippines | Formerly SEAir, South East Asian Airlines and Tigerair Philippines |
| | TLO | Eagle Canyon Airlines | TALON AIR | United States | |
| 1L | OSY | Open Skies Consultative Commission | OPEN SKIES | United States | |
| 2S | TGR | Satgur Air Transport | SATGURAIR | Liberia | defunct |
| DT | DTA | TAAG Angola Airlines | DTA | Angola | |
| | IRF | TA-Air Airline | TA-AIR | Iran | |
| | TBI | TAB Express International | TAB INTERNATIONAL | United States | |
| | TBM | Taban Air Lines | TABAN AIR | Iran | |
| | THO | TACA De Honduras | LEMPIRA | Honduras | |
| VR | TCV | TACV | CABOVERDE | Cape Verde | |
| | TDC | Tadair | TADAIR | Spain | Ceased operation in 2003 |
| | TES | Taespejo Portugal LDA | Tesaban | Portugal | |
| | HET | TAF Helicopters | HELITAF | Spain | |
| | TSD | TAF-Linhas Aéreas | TAFI | Brazil | |
| | SBT | Taftan Airlines | TAFTAN | Iran | |
| | FPG | TAG Aviation | TAG AVIATION | Switzerland | |
| | TGM | TAG Aviation Espana | TAG ESPANA | Spain | |
| | VIP | Tag Aviation UK | SOVEREIGN | United Kingdom | |
| | TAG | TAG Aviation USA | TAG U-S | United States | |
| | FBO | TAG Farnborough Airport | | United Kingdom | |
| TI | TWI | Tailwind Airlines | TAILWIND | Turkey | |
| | TIN | Taino Tours | TAINO | Dominican Republic | |
| | TFB | Tair Airways | ROYAL TEE-AIR | Philippines | |
| | TJK | Tajikair | TAJIKAIR | Tajikistan | |
| | TZK | Tajikistan International Airlines | TAJIKISTAN | Tajikistan | |
| | TKE | Take Air Line | ISLAND BIRD | France | |
| | JEL | Tal Air Charters | JETEL | Canada | |
| | TAL | Talair | TALAIR | Papua New Guinea | |
| | TFF | Talon Air | TALON FLIGHT | United States | |
| PZ | LAP | TAM Mercosur | PARAGUAYA | Paraguay | |
| EQ | TAE | TAME | TAME | Ecuador | Transporte Aéreos Militares Ecuatorianos |
| | TMI | Tamir Airways | TAMIRWAYS | Israel | |
| QT | TPA | TAMPA | TAMPA | Colombia | |
| | TNR | Tanana Air Services | TAN AIR | United States | |
| TQ | TDM | Tandem Aero | TANDEM | Moldova | |
| | HTO | Tango Bravo | HELI TANGO | France | |
| TP | TAP | TAP Portugal | AIR PORTUGAL | Portugal | |
| | UTM | TAPC Aviatrans Aircompany | AVIATAPS | Uzbekistan | |
| | TPS | TAPSA Transportes Aéreos Petroleros | TAPSA | Argentina | |
| K3 | TQN | Taquan Air Services | TAQUAN | United States | |
| | THC | Tar Heel Aviation | TARHEEL | United States | |
| | TPL | TAR Interpilot | INTERPILOT | Mauritania | |
| | IRR | Tara Air Line | TARAIR | Iran | |
| | TTH | Tarhan Tower Airlines | | Turkey | |
| RO | ROT | Tarom | TAROM | Romania | |
| | RMS | Tas Aviation | TASS AIR | United States | |
| | CTP | Tashkent Aircraft Production Corporation | CORTAS | Uzbekistan | |
| HJ | TMN | Tasman Cargo Airlines | TASMAN | Australia | |
| SF | DTH | Tassili Airlines | TASSILI AIR | Algeria | |
| | PGS | Tauranga Aer Club | | New Zealand | |
| T6 | TVR | Tavrey Airlines | TAVREY | Ukraine | |
| | TQE | Taxair Mexiqienses | TAXAIR | Mexico | |
| | TXL | Taxi Aéreo Cozatl | TAXI COZATL | Mexico | |
| | TXM | Taxi Aéreo de México | TAXIMEX | Mexico | |
| | TUO | Taxi Aéreo Turístico | TURISTICO | Mexico | |
| | XNR | Taxi Aero Del Norte | TAXI NORTE | Mexico | |
| | TDV | Taxi Aero Nacional Del Evora | TAXI EVORA | Mexico | |
| | TRF | Taxi Air Fret | TAXI JET | France | |
| | VRC | Taxi de Veracruz | VERACRUZ | Mexico | |
| | TXR | Taxirey | TAXIREY | Mexico | |
| | TPR | Taxis Aéreos De Parral | TAXIS PARRAL | Mexico | |
| | TXO | Taxis Aéreos de Sinaloa | TAXIS SINALOA | Mexico | |
| | TNE | Taxis Aéreos del Noroeste | TAXINOROESTE | Mexico | |
| | TPF | Taxis Aéreos del Pacífico | TAXIPACIFICO | Mexico | |
| | TMH | Taxis Turisticos Marakame | TAXIMARAKAME | Mexico | |
| | TYF | Tayflite | TAYFLITE | United Kingdom | |
| | TFY | Tayside Aviation | TAYSIDE | United Kingdom | |
| L6 | VNZ | Tbilaviamsheni | TBILAVIA | Georgia | |
| | RRY | Tbilisi Aviation University | AIRFERRY | Georgia | |
| | TCD | Tchad Airlines | TCHADLINES | Chad | |
| | TIM | TEAM Linhas Aéreas | TEAM BRASIL | Brazil | |
| L9 | TLW | Teamline Air | Teamline | Austria | |
| | TEM | Tech-Mont Helicopter Company | TECHMONT | Slovakia | |
| | TEF | Tecnicas Fotograficas | TECFOTO | Spain | |
| | TBN | Teebah Airlines | TEEBAH | Sierra Leone | |
| | THR | Tehran Airline | TEHRAN AIR | Iran | |
| U8 | CYF | Tel Aviv Air | TUS AIR | Germany | defunct |
| | TCM | Teledyne Continental Motors | TELEDYNE | United States | |
| | TLX | Telesis Transair | TELESIS | United States | |
| | TEL | Telford Aviation | TELFORD | United States | |
| | TDE | Tellavia / Flight One | TELLURIDE | United States | |
| | DOT | Telnic Limited | DOT TEL | United Kingdom | |
| | TEH | Tempelhof Airways | TEMPELHOF | United States | |
| | TMS | Temsco Helicopters | TEMSCO | United States | |
| | TNL | Tengeriyn Ulaach Shine | SKY HORSE | Mongolia | |
| | TEB | Tenir Airlines | TENIR AIR | Kyrgyzstan | |
| | TNG | Tennessee Air National Guard 164th Airlift Group | | United States | |
| | TEN | Tennessee Airways | TENNESSEE | United States | |
| | TET | Tepavia-Trans Airlines | TEPAVIA | Moldova | |
| | TER | Territorial Airlines | TERRI-AIRE | United States | |
| | TIS | Tesis | TESIS | Russia | |
| | TXZ | Tex Star Air Freight | TEX STAR | United States | |
| | TXA | Texair Charter | OKAY AIR | United States | |
| | TXT | Texas Air Charters | TEXAS CHARTER | United States | Group One |
| | TXS | Texas Airlines | TEXAIR | United States | |
| | CWT | Texas Airways | TEXAS AIRWAYS | United States | |
| | TXN | Texas National Airlines | TEXAS NATIONAL | United States | |
| K9 | TEZ | TezJet | Tezjet | Kyrgyzstan | Started in 2014 |
| | TGC | TG Aviation | THANET | United Kingdom | |
| T2 | TCG | Thai Air Cargo | THAI CARGO | Thailand | |
| FD | AIQ | Thai AirAsia | THAI ASIA | Thailand | |
| XJ | TAX | Thai AirAsia X | EXPRESS WING | Thailand | |
| TG | THA | Thai Airways International | THAI | Thailand | |
| | TSL | Thai Aviation Services | THAI AVIATION | Thailand | |
| TXZ | | Thai Express Air | EXPRESS AIR | Thailand | |
| | TFH | Thai Flying Helicopter Service | THAI HELICOPTER | Thailand | |
| | TFT | Thai Flying Service | THAI FLYING | Thailand | |
| | THG | Thai Global Airline | THAI GLOBAL | Thailand | |
| | THJ | Thai Jet Intergroup | THAI JET | Thailand | |
| SL | TLM | Thai Lion Mentari | MENTARI | Thailand | |
| | TPV | Thai Pacific Airlines Business | THAI PACIFIC | Thailand | |
| 9I | LLR | Thai Sky Airlines | THAI SKY AIR | Thailand | |
| WE | THD | Thai Smile Airways | THAI SMILE | Thailand | |
| T9 | TSX | Thai Star Airlines | THAI STAR | Thailand | |
| VZ | TVJ | Thai Vietjet Air | THAIVIET JET | Thailand | |
| 2H | | Thalys | | Belgium | Not an airline (train). Used for codesharing |
| | GFN | The 955 Preservation Group | GRIFFON | United Kingdom | |
| | LEG | The Army Aviation Heritage Foundation | LEGACY | United States | |
| | LCC | The Lancair Company | LANCAIR | United States | |
| HQ | TCW | Thomas Cook Airlines | KESTREL | Belgium | Defunct |
| MT | TCX | Thomas Cook Airlines | KESTREL | United Kingdom | |
| | IHS | Thryluthjonustan | | Iceland | |
| | THU | Thunder Airlines | AIR THUNDER | Canada | |
| | TBD | Thunderbird Tours | ORCA | Canada | |
| | BLI | Thyssen Krupp AG | BLUELINE | Germany | |
| GS | GCR | Tianjin Airlines | BO HAI | China | |
| 3P | TNM | Tiara Air | TIARA | Aruba | |
| | TBA | Tibet Airlines | TIBET | China | |
| | TIK | Tic Air | TICAIR | Australia | |
| | TJN | Tien-Shan | NERON | Kazakhstan | |
| TT | TGG | Tigerair Australia | TIGGOZ | Australia | Previously TGW, callsign GO CAT |
| | MDL | Tigerair Mandala | MANDALA | Indonesia | defunct, original airline code RI |
| TR | TGW | Tigerair Singapore | GO CAT | Singapore | Merged with Scoot |
| IT | TTW | Tigerair Taiwan | SMART CAT | Taiwan | |
| | MOH | Tigerfly | MOTH | United Kingdom | |
| | TKC | Tikal Jets Airlines | TIKAL | Guatemala | |
| | TMR | Timberline Air | TIMBER | Canada | |
| | TIE | Time Air | TIME AIR | Czech Republic | |
| | BOX | Tiphook PLC | BOX | United Kingdom | defunct |
| | TVI | Tiramavia | TIRAMAVIA | Moldova | |
| ZT | AWC | Titan Airways | ZAP | United Kingdom | |
| | TYJ | TJS Malta Ltd. | TYROLMALTA | Malta | |
| | TSR | TJS San Marino S.r.L. | SAN MARINO | San Marino | |
| | TLS | TLC Air | TEALSY | United States | |
| | TMM | TMC Airlines | WILLOW RUN | United States | |
| 3V | TAY | TNT Airways | QUALITY | Belgium | |
| | NTR | TNT International Aviation | NITRO | United Kingdom | |
| | TBX | Tobago Express | TABEX | Trinidad and Tobago | |
| 7T | TOB | Tobruk Air | TOBRUK AIR | Libya | |
| | TOJ | TOJ Airlines | TOJ AIRLINE | Tajikistan | |
| TI | TOL | Tol-Air Services | TOL AIR | United States | |
| | TMK | Tomahawk Airways | TOMAHAWK | United States | |
| | TOP | Top Air | AIR TOP | Indonesia | |
| | CHE | Top Flight Air Service | CHECK AIR | United States | |
| | TLY | Top Fly | TOPFLY | Spain | |
| | LKW | Top Sky International | TOPINTER | Indonesia | |
| | TPD | Top Speed | TOP SPEED | Austria | |
| | TTL | Total Linhas Aéreas | TOTAL | Brazil | |
| | TOT | Totavia | | Canada | Aviation Information Services |
| | THE | Toumai Air Tchad | TOUMAI AIR | Chad | |
| | THF | Touraine Helicoptere | TOURAINE HELICO | France | |
| | TOW | Tower Air | TEE AIR | United States | Ceased operations |
| | TOY | Toyota Canada | TOYOTA | Canada | |
| | TGE | Trabajos Aéreos | TASA | Spain | |
| | AIM | Trabajos Aéreos Murcianos | PIJO | Spain | |
| | TVH | Trabajos Aéreos Vascongados | TRAVASA | Spain | |
| | TDR | Trade Air | TRADEAIR | Croatia | |
| TJ | GPD | Tradewind Aviation | GOODSPEED | United States | |
| | TDX | Tradewinds Airlines | TRADEWINDS EXPRESS | United States | Wrangler Aviation |
| | TWL | Tradewinds Aviation | TRADEWINDS CANADA | Canada | |
| | JCH | Trading Air Cargo | TRADING CARGO | Mauritania | |
| | TDO | TRADO | TRADO | Dominican Republic | Transporte Aéreo Dominicano |
| | TRG | TRAGSA (Medios Aéreos) | | Spain | |
| | HBA | Trail Lake Flying Service | HARBOR AIR | United States | |
| | TMQ | TRAM | TRAM AIR | Mauritania | |
| | TMX | Tramon Air | TRAMON | South Africa | |
| | TRR | Tramson Limited | TRAMSON | Sudan | |
| | MUI | Trans Air | MAUI | United States | |
| | TRC | Trans Air Charter | TRACKER | United States | |
| | TWW | Trans Air Welwitchia | WELWITCHIA | Angola | |
| | TNB | Trans Air-Benin | TRANS-BENIN | Benin | |
| | RTM | Trans Am Compania | AERO TRANSAM | Ecuador | |
| | CLR | Trans America | CLINTON AIRWAYS | United States | |
| | TVA | Trans America Airlines | TRANS-AMERICA | United States | |
| | TPU | Trans American Airlines (Trans Am) | TRANS PERU | Peru | |
| | TRT | Trans Arabian Air Transport | TRANS ARABIAN | Sudan | |
| | SRT | Trans Asian Airlines | TRASER | Kazakhstan | |
| | TLL | Trans Atlantic Airlines | ATLANTIC LEONE | Sierra Leone | |
| | LTA | Trans Atlantis | LANTRA | Canada | |
| | TCC | Trans Continental Airlines | TRANSCAL | Sudan | |
| | TCN | Trans Continental Airlines | TRANSCON | United States | |
| | TRJ | Trans Euro Air | HIGH TIDE | United Kingdom | |
| | TGY | Trans Guyana Airways | TRANS GUYANA | Guyana | |
| | THZ | Trans Helicoptere Service | LYON HELIJET | France | |
| | TIA | Trans International Airlines | TRANS INTERNATIONAL | United States | |
| | BAP | Trans International Express Aviation | BIG APPLE | United States | |
| | TRD | Trans Island Air | TRANS ISLAND | Barbados | |
| | SWL | Trans Jet Airways | TRANSJET | Sweden | |
| TL | TMA | Trans Mediterranean Airlines | TANGO LIMA | Lebanon | |
| | TMT | Trans Midwest Airlines | TRANS MIDWEST | United States | |
| | TNW | Trans Nation Airways | TRANS-NATION | Ethiopia | |
| | TNT | Trans North Turbo Air | TRANS NORTH | Canada | |
| | REC | Trans Reco | TRANS-RECO | Mauritania | |
| | SBJ | Trans Sahara Air | TRANS SAHARA | Nigeria | |
| | TSM | Trans Sayegh Airport Services | | Lebanon | |
| AX | LOF | Trans States Airlines | WATERSKI | United States | |
| TW | TWA | Trans World Airlines | TWA | United States | |
| | RBD | Trans World Express | RED BIRD | United States | |
| UN | TSO | Transaero Airlines | TRANSOVIET | Russia | |
| | TNF | Transafricaine | TRANSFAS | Burkina Faso | |
| | TCG | Transafricaine Air Cargo | AFRICARGO | Burkina Faso | |
| | TFK | Transafrik International | | São Tomé and Príncipe | |
| | TSA | Transair France | AIRTRAF | France | |
| | TGX | Transair Gabon | TRANSGABON | Gabon | |
| | TNI | Transair International Linhas Aéreas | TRANSINTER | United States | |
| | TSN | Trans-Air Services | AIR TRANS | Nigeria | |
| | TSG | Trans-Air-Congo | TRANS-CONGO | Republic of the Congo | |
| | KTS | Transair-Gyraintiee | KOTAIR | Russia | |
| | GJB | Trans-Air-Link | SKY TRUCK | United States | |
| | TWM | Transairways | | Mozambique | |
| | UTT | Transarabian Transportation Services | ARABIAN TRANSPORT | Uganda | |
| GE | TNA | TransAsia Airways | | Taiwan | defunct |
| | AUC | Transaustralian Air Express | AUSCARGO | Australia | Defunct |
| | VEN | Transaven | TRANSAVEN AIRLINE | Venezuela | |
| TO | TVF | Transavia France | FRANCE SOLEIL | France | |
| HV | TRA | Transavia Holland | TRANSAVIA | Netherlands | |
| | KTB | Transaviabaltika | TRANSBALTIKA | Lithuania | |
| AL | TXC | TransAVIAexport Airlines | TRANSEXPORT | Belarus | |
| | FNV | Transaviaservice | TRANSAVIASERVICE | Georgia | |
| | TVO | Transavio | TRANS-BALLERIO | Italy | |
| TR | TBA | Transbrasil | TRANSBRASIL | Brazil | defunct |
| | TIW | Transcarga Intl Airways | TIACA | Venezuela | |
| | TCE | Trans-Colorado Airlines | TRANS-COLORADO | United States | |
| | TCH | Transcontinental Air | TRANS GULF | Bahrain | |
| | KRA | Transcontinental Airlines | REGATA | Kazakhstan | |
| | TCT | Transcontinental Sur | TRANS-CONT | Uruguay | |
| | TCP | Transcorp Airways | TRANSCORP | United Kingdom | |
| UE | TEP | Transeuropean Airlines | TRANSEURLINE | Russia | |
| | TFA | Trans-Florida Airlines | TRANS FLORIDA | United States | |
| | TCU | Transglobal Airways Corporation | TRANSGLOBAL | Philippines | |
| | TXE | Transilvania Express | TRANSAIR EXPRESS | Romania | |
| | KCA | Trans-Kiev | TRANS-KIEV | Ukraine | |
| | TLA | Translift Airways | TRANSLIFT | Ireland | |
| | TMD | Transmandu | TRANSMANDU | Venezuela | |
| | TMD | Transmed Airlines | | Egypt | |
| T9 | TRZ | TransMeridian Airlines | TRANS-MERIDIAN | United States | Defunct |
| TH | RMY | Raya Airways | TRANSMILE | Malaysia | |
| | TNV | Transnorthern | TRANSNORTHERN | United States | |
| | TPP | Transpac Express | TRANS EXPRESS | Australia | |
| | PCW | Trans-Pacific Orient Airways | PACIFIC ORIENT | Philippines | |
| | TPM | Transpaís Aéreo | TRANSPAIS | Mexico | |
| | TNP | Transped Aviation | TRANSPED | Austria | |
| | TRM | Transport Aerien de Mauritanie | SOTRANS | Mauritania | |
| | TLF | Transport Africa | TRANS-LEONE | Sierra Leone | |
| | TGO | Transport Canada | TRANSPORT | Canada | |
| | TFI | Transport Facilitators | | United States | |
| | TQR | Transportación Aérea De Querétaro | TRANSQUERETARO | Mexico | |
| | MCT | Transportación Aérea Del Mar De Cortés | TRANS CORTES | Mexico | |
| | TPN | Transportación Aérea del Norte | AEREA DELNORTE | Mexico | |
| | TTR | Transportaciones Y Servicios Aéreos | TRANSPORTACIONES | Mexico | |
| | TSI | Transport'air | TRANSPORTAIR | France | |
| | TCB | Transporte Aereo De Colombia | AERO COLOMBIA | Colombia | |
| | TAD | Transporte Aéreo Dominicano | TRANS DOMINICAN | Dominican Republic | |
| | TZE | Transporte Aéreo Ernesto Saenz | TRANSPORTE SAENZ | Mexico | |
| | TTS | Transporte Aéreo Técnico Ejecutivo | TECNICO | Mexico | |
| | MGM | Transporte Aero MGM | AERO EMM-GEE-EMM | Mexico | |
| | TMZ | Transporte Amazonair | TRANS AMAZON | Venezuela | |
| | TCB | Transporte del Caribe | TRANSCARIBE | Colombia | |
| | EAR | Transporte Ejecutivo Aéreo | EJECUTIVO-AEREO | Mexico | |
| | TPT | Transportes Aéreo del Sureste | TASSA | Mexico | |
| | MPO | Transportes Aéreos Amparo | AMPARO | Mexico | |
| | BOL | Transportes Aéreos Bolivianos | BOL | Bolivia | |
| | TDI | Transportes Aéreos de Ixtlán | TRANSIXTLAN | Mexico | |
| | TPX | Transportes Aéreos De Xalapa | TRANSXALAPA | Mexico | |
| | TMY | Transportes Aéreos del Mundo Maya | MUNDO MAYA | Mexico | |
| | TFO | Transportes Aéreos del Pacífico | TRANSPORTES PACIFICO | Mexico | |
| | DCL | Transportes Aéreos Don Carlos | DON CARLOS | Chile | |
| | ROU | Transportes Aéreos I. R. Crusoe | ROBINSON CRUSOE | Chile | |
| | TSP | Transportes Aéreos Inter | TRANSPO-INTER | Guatemala | |
| | MXQ | Transportes Aéreos Mexiquenses | MEXIQUENSES | Mexico | |
| TX | TAN | Transportes Aéreos Nacionales | | Honduras | Defunct |
| | ELV | Transportes Aéreos Nacionales De Selva Tans | AEREOS SELVA | Peru | |
| | TPG | Transportes Aéreos Pegaso | TRANSPEGASO | Mexico | |
| | TGI | Transportes Aéreos Regionales | TRANSPORTE REGIONAL | Mexico | |
| | SRF | Transportes Aéreos San Rafael | SAN RAFEAL | Chile | |
| | RRT | Transportes Aéreos Sierra | SIERRA ALTA | Mexico | |
| | SEI | Transportes Aéreos Sierra Madre | TRANSPORTE SIERRA | Mexico | |
| | TAU | Transportes Aéreos Tauro | TRANSTAURO | Mexico | |
| | TPZ | Transportes La Paz | TRANSPAZ | Mexico | |
| OF | TML | Transports et Travaux Aériens de Madagascar | TAM AIRLINE | Madagascar | |
| | TPY | Trans-Provincial Airlines | TRANS PROVINCIAL | Canada | |
| | TTC | Transteco | TRANSTECO | Angola | |
| | UTN | Trans-Ulgii | TRANS-ULGII | Mongolia | defunct |
| | TWE | Transwede Airways | TRANSWEDE | Sweden | |
| 9T | ABS | Transwest Air | ATHABASKA | Canada | |
| | TRW | Transwestern Airlines of Utah | TRANS-WEST | United States | |
| | TSW | Transwings | SWISSTRANS | Switzerland | |
| | TST | TRAST | TRAST | Kazakhstan | |
| S5 | TSJ | Trast Aero | TRAST AERO | Kyrgyzstan | |
| | TSK | Trast Aero | TOMSK-AVIA | Kyrgyzstan | |
| | TAX | Travel Air | TRAVELAIR | United States | |
| | TIC | Travel International Air Charters | TRAVEL INTERNATIONAL | Zambia | |
| | TMC | Travel Management Company | TRAIL BLAZER | United States | |
| | TLV | Travelair | PAJAROS | Uruguay | |
| 1E | | Travelsky Technology | | China | |
| | TDA | Trend Aviation | TREND AIR | United States | |
| | TNX | Trener Ltd | TRAINER | Hungary | |
| | TRU | Triangle Airline (Uganda) | TRI AIR | Uganda | |
| | SWD | Trifly | SAWBLADE | United States | |
| | TGN | Trigana Air Service | TRIGANA | Indonesia | |
| GY | TMG | Tri-MG Intra Asia Airlines | TRILINES | Indonesia | |
| | TBH | Trinity Air Bahamas | | Bahamas | |
| T4 | TIB | TRIP Linhas Aéreas | TRIP | Brazil | IATA code 8R changed to T4 (2010) |
| | CLU | Triple Alpha | CAROLUS | Germany | |
| | TTP | Triple O Aviation | MIGHTY WING | Nigeria | |
| | TSY | Tristar Air | TRIPLE STAR | Egypt | |
| | TRY | Tristar Airlines | TRISTAR AIR | United States | |
| | TSS | Tri-State Aero | TRI-STATE | United States | |
| | DRC | Triton Airlines | TRITON AIR | Canada | |
| | TSV | Tropair Airservices | TROPIC | United Kingdom | |
| PM | TOS | Tropic Air | TROPISER | Belize | |
| | TRO | Tropic Airlines-Air Molokai | MOLOKAI | United States | |
| M7 | TBG | Tropical Airways | | Haiti | |
| | TKX | Tropical International Airways | TROPEXPRESS | Saint Kitts and Nevis | |
| | TCA | Tropican Air Services | TROPICANA | Egypt | |
| | TYG | Trygg-Flyg | TRYGG | Sweden | |
| TZ | TDS | Tsaradia | TSARADIA | Madagascar | |
| | PSS | TSSKB-Progress | PROGRESS | Russia | |
| | TTA | TTA - Sociedade de Transporte e Trabalho Aéreo | KANIMANBO | Mozambique | |
| | TBR | Tubelair | TUBELAIR | Tunisia | |
| BY | TOM | TUI Airways | TOM JET | United Kingdom | Formerly "TOMSON" |
| TB | JAF | TUI fly Belgium | BEAUTY | Belgium | |
| X3 | TUI | TUI fly Deutschland | TUI JET | Germany | |
| OR | TFL | TUI fly Netherlands | ORANGE | Netherlands | |
| 6B | BLX | TUI fly Nordic | BLUESCAN | Sweden | |
| TD | TLP | Tulip Air | TULIPAIR | Netherlands | |
| | TUL | Tulpar Air | URSAL | Russia | |
| | TUX | Tulpar Air Service | TULPA | Kazakhstan | |
| | TUZ | Tuna Aero | TUNA | Sweden | |
| UG | TUX | Tuninter | | Tunisia | |
| TU | TAR | Tunisair | TUNAIR | Tunisia | |
| | TAJ | Tunisavia | TUNISAVIA | Tunisia | |
| 3T | URN | Turan Air | TURAN | Azerbaijan | |
| | TBC | Turbine Air Cargo UK | | United Kingdom | |
| | TAC | Turbot Air Cargo | TURBOT | Senegal | |
| | TRQ | Turdus Airways | HUNTER | Netherlands | Defunct, ICAO code in use by another airline |
| | TUC | Turismo Aéreo de Chile | TURICHILE | Chile | |
| | THK | Turk Hava Kurumu Hava Taksi Isletmesi | HUR KUS | Turkey | |
| | THS | Turkish Aerospace Industries | TUSAS | Turkey | |
| | HVK | Turkish Air Force | TURKISH AIRFORCE | Turkey | |
| TK | THY | Turkish Airlines | TURKISH | Turkey | |
| | TRK | Turkish Airlines General Aviation | TURKISH REPUBLIC | Turkey | |
| T5 | TUA | Turkmenistan Airlines | TURKMENISTAN | Turkmenistan | |
| | TLT | Turtle Airways | TURTLE | Fiji | |
| | USB | Tusheti | TUSHETI | Georgia | |
| TW | TWB | T'way Air | TWAYAIR | Republic of Korea | |
| | TWO | Twente Airlines | COLIBRI | Netherlands | |
| | TCY | Twin Cities Air Service | TWIN CITY | United States | |
| T7 | TJT | Twin Jet | TWINJET | France | |
| | TNY | Twin Town Leasing Company | TWINCAL | United States | |
| | TWJ | Twinjet Aircraft Sales | | United Kingdom | |
| | TYW | Tyrol Air Ambulance | TYROL AMBULANCE | Austria | |
| VO | TYR | Tyrolean Airways | TYROLEAN | Austria | Renamed from Austrian Arrows |
| | TJS | Tyrolean Jet Services | TYROLJET | Austria | |
| | TUM | Tyumenspecavia | TUMTEL | Russia | |
| VNX | TKK | flyADVANCED | TARKA | United States | Aero Ways Inc. flyADVANCED |
| | UEU | United European Airlines | UNITED EUROPEAN | Romania | 2014 |
| | UCG | Uniworld Air Cargo | UNIWORLD | Panama | 2014 |
| | CUH | Urumqi Airlines | LOULAN | China | 2014 |
| | DOD | USAF Air Mobility Operations Control Center | | United States | |
| | DOI | U.S. Department of the Interior | INTERIOR | United States | Office of Aircraft Services |
| | CNV | U.S. Navy Reserve Logistic Air Forces | CONVOY | United States | U.S. Navy Reserve Logistic Air Forces, New Orleans, LA, USA |
| | EXM | United Kingdom Civil Aviation Authority | EXAM | United Kingdom | CAA Flight Examiners |
| | GIH | Union des Transports Africains de Guinee | TRANSPORT AFRICAIN | Guinea | |
| | GKA | US Army Parachute Team | GOLDEN KNIGHTS | United States | |
| | GWY | USA3000 Airlines | GETAWAY | United States | was U5 |
| B7 | UIA | UNI Air | GLORY | Taiwan | |
| | UAB | United Arabian Airlines | UNITED ARABIAN | Sudan | |
| UA | UAL | United Airlines | UNITED | United States | |
| 4H | UBD | United Airways | UNITED BANGLADESH | Bangladesh | |
| | UAC | United Air Charters | UNITAIR | Zimbabwe | |
| | UCS | United Carriers Systems | UNITED CARRIERS | United States | |
| | UEA | United Eagle Airlines | UNITED EAGLE | China | |
| | UFS | United Feeder Service | FEEDER EXPRESS | United States | formerly part of United Express |
| | CFU | United Kingdom Civil Aviation Authority | MINAIR | United Kingdom | Civil Aviation Authority Flying Unit |
| | KRF | United Kingdom Royal VIP Flights | KITTYHAWK | United Kingdom | In Military Aircraft |
| | KRH | United Kingdom Royal VIP Flight | SPARROWHAWK | United Kingdom | In Civil Chartered Aircraft |
| | SDS | United Kingdom Civil Aviation Authority | STANDARDS | United Kingdom | Training Standards |
| | TQF | United Kingdom Royal VIP Flights | RAINBOW | United Kingdom | Helicopter Flights |
| | CGX | United States Coast Guard Auxiliary | COASTGUARD AUXAIR | United States | |
| | AGR | United States Department Of Agriculture | AGRICULTURE | United States | |
| | UAD | University Air Squadron | | United Kingdom | MOD Boscombe Down |
| | UAJ | University Air Squadron | | United Kingdom | Glasgow |
| | UAA | University Air Squadron | | United Kingdom | Leuchars |
| | UAS | University Air Squadron | | United Kingdom | RAF Cranwell |
| | HBU | Universal Avia | KHARKIV UNIVERSAL | Ukraine | |
| | HLE | UK HEMS | HELIMED | United Kingdom | |
| U7 | JUS | USA Jet Airlines | JET USA | United States | |
| | LEA | Unijet | LEADAIR | France | |
| | MSH | US Marshals Service | MARSHALAIR | United States | US Department of Justice |
| | NDU | University of North Dakota | SIOUX | United States | |
| | PNA | Universal Airlines | PACIFIC NORTHERN | United States | |
| | | Upali Air | UPALI | Sri Lanka | defunct |
| | RAU | Uganda Royal Airways | UGANDA ROYAL | Uganda | |
| | SAU | United Aviation Services | UNISERVE | Spain | |
| U6 | SVR | Ural Airlines | SVERDLOVSK AIR | Russia | |
| | TRB | Ukraine Transavia | KIROVTRANS | Ukraine | |
| | UAF | United Arab Emirates Air Force | UNIFORCE | United Arab Emirates | |
| | UAI | Union Africaine des Transports | UNAIR | Ivory Coast | |
| | UCC | Uganda Air Cargo | UGANDA CARGO | Uganda | |
| | UCH | US Airports Air Charter | US CHARTER | United States | |
| | UCO | Ucoaviacion | UCOAVIACION | Spain | |
| | UES | Ues-Avia Aircompany | AVIASYSTEM | Ukraine | |
| QU | UGA | Uganda Airlines (1976–2001) | UGANDA | Uganda | Ceased operations 2001 |
| UR | UGD | Uganda Airlines | CRESTED | Uganda | Started operations in 2019 |
| | UGC | Urgemer Canarias | URGEMER | Spain | |
| | UHL | Ukrainian Helicopters | UKRAINE COPTERS | Ukraine | |
| | UHS | Ulyanovsk Higher Civil Aviation School | PILOT AIR | Russia | |
| | UJR | Universal Jet Rental de Mexico | UNIVERSAL JET | Mexico | |
| | UJT | Universal Jet Aviation | UNI-JET | United States | Cancelled 2014 - Renamed Journey Aviation with code JNY |
| | UKI | UK International Airlines | KHALIQ | United Kingdom | |
| | UKL | Ukraine Air Alliance | UKRAINE ALLIANCE | Ukraine | |
| UF | UKM | UM Airlines | UKRAINE MEDITERRANEE | Ukraine | Ukraine Mediterranean Airlines |
| | UKN | Ukraine Air Enterprise | ENTERPRISE UKRAINE | Ukraine | |
| | UKP | National Police Air Service | POLICE | United Kingdom | |
| 6Z | UKS | Ukrainian Cargo Airways | CARGOTRANS | Ukraine | |
| | ULT | Ultrair | ULTRAIR | United States | |
| | ULH | Ultimate HELI | ULTIMATEHELI | South Africa | Ultimate HELI (Pty) Ltd |
| | ULR | Ultimate Air | VIPER | South Africa | Ultimate Airways (Pty) Ltd |
| OL | ULS | Ultra Air | AIR ULTRA | Colombia | |
| | UNC | Uni-Fly | UNICOPTER | Denmark | |
| | UNF | Union Flights | UNION FLIGHTS | United States | |
| | UNJ | Universal Jet | PROJET | Spain | |
| | UNS | Unsped Paket Servisi | UNSPED | Turkey | |
| | UNU | Unifly Servizi Aerei | UNIEURO | Italy | |
| | UPL | Ukrainian Pilot School | PILOT SCHOOL | Ukraine | |
| 5X | UPS | United Parcel Service | UPS | United States | |
| | URV | Uraiavia | URAI | Russia | |
| US | AWE | US Airways | CACTUS | United States | defunct, merged with American Airlines in 2015 |
| BS | UBG | US-Bangla Airlines | BANGLA STAR | Bangladesh | |
| | USF | USAfrica Airways | AFRICA EXPRESS | United States | |
| UH | USH | US Helicopter | US-HELI | United States | |
| | USJ | US Jet | USJET | United States | |
| | USX | US Express | AIR EXPRESS | United States | |
| QU | UTN | UTair-Ukraine | UT Ukraine | Ukraine | |
| | TUM | UTAir | UTAIR-CARGO | Russian Federation | 2014 |
| UT | UTA | UTair Aviation | UTAIR | Russia | WAS P2 till 2006 |
| | UTR | Utair South Africa | AIRUT | South Africa | |
| | UTS | Ukrainian State Air Traffic Service Enterprise | AIRRUH | Ukraine | |
| | UTU | Urartu-Air | | Armenia | |
| | UVA | Universal Airways | UNIVERSAL | United States | |
| | UVG | Universal Airlines | GUYANA JET | Guyana | |
| | UVM | Uvavemex | UVAVEMEX | Mexico | |
| | AIO | United States Air Force | AIR CHIEF | United States | Chief of Staff |
| | UVN | United Aviation | UNITED AVIATION | Kuwait | |
| HY | UZB | Uzbekistan Airways | UZBEK | Uzbekistan | |
| PS | AUI | Ukraine International Airlines | UKRAINE INTERNATIONAL | Ukraine | |
| | WEC | Universal Airlines | AIRGO | United States | |
| US | | Unavia Suisse | | Switzerland | |
| | QID | USAF 100th Air Refueling Wing | QUID | United States | |
| | UIT | University of Tromsø School of Aviation | ARCTIC | Norway | |
| | UNO | United Nations | UNITED NATIONS | n/a | UNOxxx followed by P(peacekeeping), or H(Humanitarian) |
| JW | VNL | Vanilla Air | VANILLA | Japan | Merged with Peach Aviation |
| VU | VAG | Vietravel Airlines | VIETRAVEL AIR | Vietnam | |
| | VAI | Volant Aviation International | | Pakistan | |
| | VAR | Veca Airlines | VECA | El Salvador | |
| | VLR | Volare 22 X | VOLAX | Mexico | |
| | VDR | Voldirect | VOLDIR | France | |
| | VVV | Valair Aviação Lda | VALAIRJET | Portugal | |
| VB | VIV | VivaAerobus | VIVA | Mexico | |
| | VIL | V I Airlink | TURTLE DOVE | British Virgin Islands | |
| VA | VOZ | Virgin Australia | VELOCITY | Australia | Previously Used: KANGA, AURORA, VEE-OZ |
| | VBA | V Bird Airlines Netherlands | VEEBEE | Netherlands | |
| | WIW | V-avia Airline | VEE-AVIA | Ukraine | |
| | VBD | V-Berd-Avia | VEEBIRD-AVIA | Armenia | |
| | VAC | Vacationair | VACATIONAIR | Canada | |
| | RDW | Valair AG (Helicoptere) | ROADWATCH | Switzerland | |
| | VLA | Valan International Cargo Charter | NALAU | South Africa | |
| | VLN | Valan Limited | VALAN | Moldova | |
| | EHR | Valfell-Verkflug | ROTOR | Iceland | |
| VF | VLU | Valuair | VALUAIR | Singapore | Merged with Jetstar Asia 2014 |
| VF | | AnadoluJet | AJet | Turkiye | |
| J7 | VJA | ValuJet Airlines | CRITTER | United States | Now operating as AirTran Airways. J7 Reassigned. |
| | VJA | Vista America | ICONIC | United States | Using the ICAO code that was previously assigned to ValuJet Airlines. |
| | VAA | Van Air Europe | EUROVAN | Czech Republic | |
| | VGC | Vanguardia en Aviación en Colima | VANGUARDIA COLIMA | Mexico | |
| | VGD | Vanguard Airlines | VANGUARD AIR | United States | |
| | VRH | Varesh Airlines | SKY VICTOR | Iran | |
| 0V | VFC | Vietnam Air Services Company (VASCO) | VASCO AIR | Vietnam | |
| | VAG | Vega | SEGA | Kazakhstan | |
| | WGA | Vega Air Company | WEGA FRANKO | Ukraine | |
| | WEL | Veles, Ukrainian Aviation Company | VELES | Ukraine | |
| | VTX | Verataxis | VERATAXIS | Mexico | |
| | BTP | Veritair | NET RAIL | United Kingdom | |
| VC | VAL | Voyageur Airways | VOYAGEUR | Canada | |
| | GRV | Vernicos Aviation | NIGHT RIDER | Greece | |
| VN | HVN | Vietnam Airlines | VIET NAM | Vietnam | |
| | TMB | Volato | Tombo | United States | |
| | KWA | Vozdushnaya Academy | VOZAIR | Kazakhstan | |
| NN | MOV | VIM Airlines | MOV AIR | Russia | |
| | MVY | VIM-Aviaservice | | Russia | |
| 2R | | Via Rail Canada | | Canada | |
| | ENV | Victoria Aviation | ENDEAVOUR | United Kingdom | |
| | VCT | Viscount Air Service | VISCOUNT AIR | United States | |
| | SSI | Vision Airlines | SUPER JET | Nigeria | |
| | FXF | VIP Air Charter | FOX FLIGHT | United States | |
| | PAV | VIP Avia | NICOL | Kazakhstan | |
| | PRX | VIP Avia | PAREX | Latvia | |
| | VAT | Visionair | VISIONAIR | Ireland | |
| VA | | Viasa | | Venezuela | IATA Code transferred to Virgin Australia |
| | VCA | VICA - Viacao Charter Aéreos | VICA | Brazil | |
| | VCM | Volare Air Charter Company | CARMEN | United States | |
| Y4 | VOI | Volaris | VOLARIS | Mexico | |
| VI | VDA | Volga-Dnepr Airlines | VOLGA | Russia | |
| | VEA | Vega Airlines | VEGA AIRLINES | Bulgaria | |
| | VEC | Venescar Internacional | VECAR | Venezuela | |
| | VEE | Victor Echo | VICTOR ECHO | Spain | |
| | VEI | Virgin Express Ireland | GREEN ISLE | Ireland | defunct |
| VX | VRD | Virgin America | REDWOOD | United States | Merged with Alaska Airlines |
| VJ | VJC | Vietjet Air | VIETJET | Vietnam | |
| V4 | VES | Vieques Air Link | VIEQUES | United States | |
| TV | VEX | Virgin Express | VIRGIN EXPRESS | Belgium | defunct |
| | VFT | VZ Flights | ZETA FLIGHTS | Mexico | |
| VK | VGN | Virgin Nigeria Airways | VIRGIN NIGERIA | Nigeria | |
| | VGV | Vologda State Air Enterprise | VOLOGDA AIR | Russia | |
| | VHA | VH-Air Industrie | AIR V-H | Angola | |
| | VHM | VHM Schul-und-Charterflug | EARLY BIRD | Germany | |
| | VIB | Vibroair Flugservice | VITUS | Germany | |
| | VIC | VIP Servicios Aéreos Ejecutivos | VIP-EJECUTIVO | Mexico | |
| | VIE | VIP Empresarial | VIP EMPRESARIAL | Mexico | |
| | VIF | VIF Luftahrt | VIENNA FLIGHT | Austria | |
| | VIG | Vega Aviation | VEGA AVIATION | Sudan | |
| | VIH | Vichi | VICHI | Moldova | |
| | VIK | Viking Airlines | SWEDJET | Sweden | |
| | VIN | Vinair Aeroserviços | VINAIR | Portugal | |
| VS | VIR | Virgin Atlantic | VIRGIN | United Kingdom | |
| | VJM | Viajes Ejecutivos Mexicanos | VIAJES MEXICANOS | Mexico | |
| | VJT | Vistajet | VISTA | Canada | |
| | VJT | Vistajet | VISTA MALTA | Malta | 2014 |
| ZG | VVM | Viva Macau | JACKPOT | Macao | defunct |
| VE | VLE | C.A.I. Second | VOLA | Italy | |
| VY | VLG | Vueling Airlines | VUELING | Spain | |
| XF | VLK | Vladivostok Air | VLADAIR | Russia | Merged with Aurora |
| LC | VLO | Varig Logística | VELOG | Brazil | defunct |
| | VLT | Vertical-T Air Company | VERTICAL | Russia | |
| | VMA | Vero Monmouth Airlines | VERO MONMOUTH | United States | |
| | VNK | Vipport Joint Stock Company | | Russia | |
| VM | VOA | Viaggio Air | VIAGGIO | Bulgaria | |
| | VOG | Voyager Airlines | VOYAGER AIR | Bangladesh | |
| 9V | VPA | Vipair Airlines | VIAIR | Kazakhstan | defunct |
| | VPB | Veteran Air | VETERAN | Ukraine | |
| | VPV | VIP-Avia | VIP AVIA | Georgia | |
| | VRA | Vertair | VERITAIR | United Kingdom | |
| | VRE | Volare Airlines | UKRAINE VOLARE | Ukraine | |
| | VRL | Voar Lda | VOAR LINHAS | Angola | |
| RG | VRN | Varig | VARIG | Brazil | |
| VH | VVC | Viva Air Colombia | Viva Air Colombia | Colombia | Commenced operations on May 25, 2012 |
| | VSB | Vickers Limited | VICKERS | United Kingdom | |
| | VSN | Vision Airways Corporation | VISION | Canada | |
| | VSO | Voronezh Aircraft Manufacturing Society | VASO | Russia | |
| VP | VSP | VASP | VASP | Brazil | defunct |
| | VSS | Virign Islands Seaplane Shuttle | WATERBIRD | United States | |
| | VTC | Vuelos Especializados Tollocan | VUELOS TOLLOCAN | Mexico | |
| | VTH | Vuelos Corporativos de Tehuacan | VUELOS TEHUACAN | Mexico | |
| V7 | VOE | Volotea | VOLOTEA | Spain | |
| | VTK | Vostok Airlines | VOSTOK | Russia | |
| | VTL | Victor Tagle Larrain | VITALA | Chile | |
| | VTV | Vointeh | VOINTEH | Bulgaria | |
| | VUR | VIP Ecuador | VIPEC | Ecuador | defunct |
| | VUS | Vuela Bus | VUELA BUS | Mexico | |
| | VZL | Vzlyet | VZLYET | Russia | |
| VG | VLM | VLM Airlines | RUBENS | Belgium | defunct |
| | WCY | Viking Express | TITAN AIR | United States | |
| | WEV | Victoria International Airways | VICTORIA UGANDA | Uganda | |
| G6 | WLG | Air Volga | GOUMRAK | Russia | |
| | VNR | Viennair | VIENNAIR | Austria | defunct |
| UK | VTI | Vistara | Vistara | India | Commenced operations 9 January 2015 |
| WD | WDL | WDL Aviation | WDL | Germany | |
| | WRR | WRA Inc | WRAP AIR | United States | |
| | XWS | WSI Corporation | | United States | |
| | CGG | Walmart Aviation | CHARGE | United States | |
| | WAS | Walsten Air Services | WALSTEN | Canada | |
| | GOT | WaltAir | GOTHIC | Sweden | |
| | WPT | Wapiti Aviation | WAPITI | Canada | |
| | WAV | Warbelow's Air Ventures | WARBELOW | United States | |
| | ATX | Warwickshire Aerocentre Ltd. | AIRTAX | United Kingdom | |
| WT | WSG | Wasaya Airways | WASAYA | Canada | |
| | | Wayraperú | WAYRAPERÚ | Peru | |
| | WTC | Weasua Air Transport Company | WATCO | Liberia | |
| WH | WEB | WebJet Linhas Aéreas | WEB-BRASIL | Brazil | |
| | TDB | Welch Aviation | THUNDER BAY | United States | |
| 2W | WLC | Welcome Air | WELCOMEAIR | Austria | |
| | BLW | Wermlandsflyg AB | BLUESTAR | Sweden | |
| | WCB | West Africa Airlines | KILO YANKEE | Ghana | |
| | WTF | West African Air Transport | WESTAF AIRTRANS | Senegal | |
| WZ | WSF | West African Airlines | | Benin | |
| | WAC | West African Cargo Airlines | WESTAF CARGO | Mauritania | |
| PN | CHB | West Air (China) | WEST CHINA | China | |
| | WLX | West Air Luxembourg | WEST LUX | Luxembourg | |
| T2 | SWN | West Atlantic Sweden | AIR SWEDEN | Sweden | |
| YH | WCW | West Caribbean Airways | WEST | Colombia | |
| | WCR | West Caribbean Costa Rica | WEST CARIBBEAN | Costa Rica | |
| 8O | YWZ | West Coast Air | COAST AIR | Canada | |
| | | West Coast Airlines | | United States | |
| | WCG | West Coast Airlines | WHISKY INDIA | Ghana | |
| | WCA | West Coast Airways | WEST-LEONE | Sierra Leone | |
| | WCC | West Coast Charters | WEST COAST | United States | |
| | TEE | West Freugh DTEO | TEEBIRD | United Kingdom | |
| | WEW | West Wind Aviation | WESTWIND | Canada | |
| WS | WJA | WestJet | WESTJET | Canada | |
| | WAA | Westair Aviation | WESTAIR WINGS | Namibia | |
| | WSC | Westair Cargo Airlines | WESTCAR | Côte d'Ivoire | |
| | PCM | Westair Industries | PAC VALLEY | United States | |
| | BLK | Westcoast Energy | BLUE FLAME | Canada | |
| ST* | STT | Western Aircraft, Inc | SAWTOOTH | United States | |
| | WST | Western Air | WESTERN BAHAMAS | Bahamas | |
| | NPC | Western Air Couriers | NORPAC | United States | |
| | WAE | Western Air Express | WESTERN EXPRESS | United States | |
| WA | WAL | Western Airlines | WESTERN | United States | defunct |
| WA | KLC | KLM Cityhopper | CITY | the Netherlands | |
| | WAL | Western Arctic Air | WESTERN ARCTIC | Canada | |
| | WTV | Western Aviators | WESTAVIA | United States | |
| | AAE | Western Express Air | ARIZONA | United States | defunct in 2007 |
| | WES | Western Express Air Lines | WEST EX | Canada | |
| | WGN | Western Global Airlines | WESTERN GLOBAL | United States | Allocated in 2014 |
| W7 | KMR | Western Pacific Airlines | KOMSTAR | United States | |
| | WPA | Western Pacific Airservice | WESTPAC | Solomon Islands | |
| | WSL | Westflight Aviation | WEST LINE | United Kingdom | |
| | WSA | Westgates Airlines | WESTATES | United States | |
| | WHE | Westland Helicopters | WESTLAND | United Kingdom | |
| | WTP | Westpoint Air | WESTPOINT | Canada | |
| CN | WWD | Westward Airways | WESTWARD | United States | |
| | WHT | White | WHITEJET | Portugal | |
| | WEA | White Eagle Aviation | WHITE EAGLE | Poland | |
| | WRA | White River Air Services | | Canada | |
| | WWL | Whyalla Airlines | | Australia | |
| WF | WIF | Widerøe | WIDEROE | Norway | |
| WC | WAA | Wien Air Alaska | WIEN | United States | Wien Consolidated Airlines from 1968-1973 |
| | WIG | Wiggins Airways | WIGGINS AIRWAYS | United States | |
| | WHS | Wiking Helikopter Service | WEEKING | Germany | |
| | WFO | Wilbur's Flight Operations | WILBURS | United States | |
| | WGP | Williams Grand Prix Engineering | GRAND PRIX | United Kingdom | |
| | WDA | Wimbi Dira Airways | WIMBI DIRA | Democratic Republic of Congo | |
| | WNA | Winair | WINAIR | United States | |
| IV | JET | Wind Jet | GHIBLI | Italy | |
| | WSI | Wind Spirit Air | WIND SPIRIT | United States | |
| 7W | QGA | Windrose Air | QUADRIGA | Germany | |
| | WIA | Windward Islands Airways International | WINDWARD | Netherlands | |
| IW | WON | Wings Air | WINGS ABADI | Indonesia | Subsidiary of Lion Air |
| | WAT | Wings Air Transport | | Sudan | |
| | WAW | Wings Airways | WING SHUTTLE | United States | |
| | WOL | Wings Aviation | WINGJET | Guyana | |
| | WEX | Wings Express | WINGS EXPRESS | United States | |
| | WLB | Wings of Lebanon Aviation | WING LEBANON | Lebanon | |
| | WIN | Winlink | WINLINK | Saint Lucia | |
| | WAG | Wisconsin Air National Guard | | United States | |
| | WSM | Wisman Aviation | WISMAN | United States | |
| 8Z | WVL | Wizz Air Bulgaria | WIZZBUL | Bulgaria | defunct in 2011 |
| W6 | WZZ | Wizz Air | WIZZAIR | Hungary | |
| W4 | WMT | Wizz Air Malta | WIZZ AIR MALTA | Malta | |
| W9 | WUK | Wizz Air UK | WIZZ GO | United Kingdom | |
| | WNR | Wondair on Demand Aviation | WONDAIR | Spain | |
| | CWY | Woodgate Aviation | CAUSEWAY | United Kingdom | |
| WO | WOA | World Airways | WORLD | United States | |
| | XWW | World Weatherwatch | | Canada | |
| | WWM | World Wing Aviation | MANAS WING | Kyrgyzstan | |
| 1P | | Worldspan | | United States | |
| UI | CSW | SW Italia | SILKITALIA | Italy | |
| | WWS | Worldwide Aviation Services | | Pakistan | |
| | WWI | Worldwide Jet Charter | WORLDWIDE | United States | |
| WW | WOW | WOW air | WOW air | Iceland | |
| | WRT | Wright Airlines | WRIGHT-AIR | United States | defunct |
| 8V | WRF | Wright Air Service | WRIGHT FLYER | United States | |
| | CWU | Wuhan Airlines | WUHAN AIR | China | |
| | WYC | Wycombe Air Centre | WYCOMBE | United Kingdom | |
| | WYG | Wyoming Airlines | WYOMING | United States | |
| KW | WAN | Wataniya Airways | WATANIYA | Kuwait | |
| 3W* | VNR | Wan Air | WANAIR | French Polynesia | defunct |
| WR | WEN | WestJet Encore | ENCORE | Canada | |
| | XJE | X-Jet | | Austria | |
| | XAB | Xabre Aerolineas | AERO XABRE | Mexico | |
| | XAE | Xair | AURA | Czech Republic | |
| | XJC | XJC Limited | EXCLUSIVE JET | United Kingdom | |
| | XER | Xerox Corporation | XEROX | United States | |
| 7A | XRC | Express Air Cargo | TUNISIA CARGO | Tunisia | |
| MF | CXA | Xiamen Airlines | XIAMEN AIR | China | |
| | CXJ | Xinjiang Airlines | XINJIANG | China | |
| | XJT | Xjet Limited | XRAY | United Kingdom | |
| SE | SEU | XL Airways France | STARWAY | France | |
| | GXL | XL Airways Germany | STARDUST | Germany | |
| | XOJ | XOJet | EXOJET | United States | |
| | XPS | XP International | XP PARCEL | Netherlands | |
| | | Xpedite | BIGSPLASH | United Kingdom | |
| XN | XAR | XpressAir | XPRESS | Indonesia | Renamed from Travel Express Aviation Services in 2012 |
| | RAG | Xstrata Nickel (Raglan Mine) | RAGLAN | Canada | |
| | DGA | Yellow River Delta General Aviation | YELLOW RIVER | China | |
| | YRG | Yak Air | YAKAIR GEORGIA | Georgia | |
| | AKY | Yak-Service | YAK-SERVICE | Russia | |
| | YAK | Yakolev | YAK AVIA | Russia | Yak Design Bureau |
| YL | LLM | Yamal Airlines | YAMAL | Russia | |
| R3 | SYL | Yakutia Airlines | AIR YAKUTIA | Russia | |
| | CYG | Yana Airlines | VICAIR | Cambodia | |
| | AYG | Yangon Airways | AIR YANGON | Burma | |
| Y8 | YZR | Suparna Airlines | YANGTZE RIVER | China | Former name: Yangtze River Express |
| | LYH | Yankee Lima Helicopteres | HELIGUYANE | France | |
| | MHD | Yas Air Kish | YAS AIR | Iran | |
| Y0 | EMJ | Yellow Air Taxi/Friendship Airways | | United States | |
| | ELW | Yellow Wings Air Services | YELLOW WINGS | Kenya | |
| IY | IYE | Yemenia | YEMENI | Yemen | |
| | ERV | Yerevan-Avia | YEREVAN-AVIA | Armenia | |
| YT | NYT | Yeti Airlines | YETI AIRLINES | Nepal | Domestic |
| | YFS | Young Flying Service | YOUNG AIR | United States | |
| | AYU | Yuhi Air Lines | | Japan | |
| | AYE | Yunnan Yingan Airlines | AIR YING AN | China | |
| 4Y | TUD | Yute Air Alaska | TUNDRA | United States | defunct 2017 |
| | UGN | Yuzhnaya Aircompany | PLUTON | Kazakhstan | |
| 2N | UMK | Yuzhmashavia | YUZMASH | Ukraine | |
| | BZE | Zenith Aviation | ZENSTAR | United Kingdom | 2014 |
| | AZB | Zaab Air | ZAAB AIR | Ghana | |
| | AZJ | Zas Air | | Egypt | |
| | AZR | Zenith Air | ZENAIR | South Africa | |
| | CDC | Zhejiang Loong Airlines | HUALONG | China | |
| | CIT | Zanesville Aviation | ZANE | United States | |
| | EMR | Zenmour Airlines | ZENMOUR | Mauritania | |
| | EZD | Zest Airways | ZEST AIRWAYS | Philippines | |
| | GZQ | Zagros Air | ZAGROS | Iraq | |
| C4 | IMX | Zimex Aviation | ZIMEX | Switzerland | |
| | IZG | Zagros Airlines | ZAGROS | Iran | |
| | JTU | Zhetysu | ZHETYSU | Kazakhstan | |
| | KVZ | Z-Aero Airlines | | Ukraine | |
| | KZH | Zhez Air | | Kazakhstan | |
| | MBG | Zephyr Aviation | CHALGROVE | United Kingdom | |
| | MLU | Zracno Pristaniste Mali Losinj | MALI LOSINJ | Croatia | |
| | MZE | Zenith Aviation (Malta) | | Malta | |
| | ORZ | Zorex | ZOREX | Spain | |
| | PZY | Zapolyarye Airline Company | ZAPOLYARYE | Russia | |
| | RZR | Zephyr Express | RECOVERY | United States | |
| | RZU | Zhersu Avia | ZHERSU AVIA | Kazakhstan | |
| | SYZ | Zil Air | ZIL AIR | Seychelles | |
| | TAN | Zanair | ZANAIR | Tanzania | |
| | ZAI | Zaire Aero Service | ZASAIR | Democratic Republic of Congo | |
| | ZAK | Zambia Skyways | ZAMBIA SKIES | Zambia | |
| | ZAR | Zairean Airlines | ZAIREAN | Domocratic Republic of Congo | |
| | ZAV | Zetavia | ZETAVIA | Ukraine | |
| | ZAW | Zoom Airways | ZED AIR | Bangladesh | |
| | ZMA | Zambezi Airlines | ZAMBEZI WINGS | Zambia | |
| | RZV | Z-Avia | ZEDAVIA | Armenia | ICAO Code and callsign no longer allocated |
| Q3 | MBN | Zambian Airways | ZAMBIANA | Zambia | |
| | ZAN | Zantop International Airlines | ZANTOP | United States | ICAO Code and callsign no longer allocated |
| | ZAS | ZAS Airlines of Egypt | ZAS AIRLINES | Egypt | ICAO Code and callsign no longer allocated |
| | CJG | Zhejiang Airlines | ZHEJIANG | China | ICAO Code and callsign no longer allocated |
| | CFZ | Zhongfei General Aviation | ZHONGFEI | China | |
| | CYN | Zhongyuan Aviation | ZHONGYUAN | China | ICAO Code and callsign no longer allocated |
| 3J | WZP | Zip | ZIPPER | Canada | ICAO Code and callsign no longer allocated |
| ZG | TZP | Zipair Tokyo | ZIPPY | Japan | Subsidiary of Japan Airlines |
| Z4 | OOM | Zoom Airlines | ZOOM | Canada | defunct, ICAO Code and callsign no longer allocated |
| | ORZ | Zorex | ZOREX | Spain | |
    $^*$ on IATA code indicates a controlled duplicate.
    italics indicates a defunct airline.