9-1-1 or 911 (usually pronounced "nine-one-one") is the emergency telephone number for the North American Numbering Plan (NANP). It is one of eight N11 codes.  The use of this number is reserved for true emergency circumstances only.  Use of 9-1-1 under non-emergency circumstances may result in a criminal charge.

# Development of 9-1-1
Before the dial telephone came into widespread usage, a caller simply picked up the telephone receiver and waited for the operator to answer "number please?"  The caller then said "connect me to the police," "I want to report a fire," or "I need an ambulance/doctor."  It was usually not necessary to ask for any of these services by number, even in a large city.  Furthermore, the operator instantly knew the calling party's number even if he couldn't stay on the line by simply looking at the number above the line jack of the calling party.
In small towns, telephone operators frequently went the extra mile by making sure they knew the locations of local doctors, vets, law enforcement personnel, and even private citizens who were willing or able to help in an emergency.  Frequently, the operator also activated the town's fire alarm.
When cities and towns began to convert to dial or, "automatic" telephone service, many people were concerned about the loss of the personalized service that had been provided by local operators.  This problem was partially solved by telling people to dial "0" for the local assistance operator if they did not know the Fire or Police Department's full number.
Generations of school children were taught to "dial 0 in case of emergency," and this situation remained in place in some areas into the early 1980s.  Nowadays children are taught to call 911.
The push for the development of a nationwide emergency telephone number came in 1957 when the National Association of Fire Chiefs recommended a single number to be used for reporting fires. In 1967, the President's Commission on Law Enforcement and Administration of Justice recommended the creation of a single number that can be used nationwide for reporting emergencies. The burden then fell on the Federal Communications Commission, which then met with AT&T in November 1967 in order to come up with a solution.
In 1968, a solution was agreed upon. AT&T had chosen the number 911, which met the requirements that it be brief, easy to remember, dialed easily, and that it worked well with the phone systems in place at the time. How the number 911 itself was chosen is not well known and is subject to much speculation. However, many assert that the number 911 was chosen to be similar to the numbers 2-1-1 (long distance), 4-1-1 (information, later called "directory assistance"), and 6-1-1 (repair service), which had already been in use by AT&T since 1966.  Also, it was necessary to ensure that the 9-1-1 number was not dialed accidentally, so 9-1-1 made sense because the numbers "9" and "1" were on opposite ends of a phone's rotary dial.
Furthermore, the North American Numbering Plan in use at the time established rules for which numbers can be used for area codes and exchanges. At the time, the middle digit of an area code had to be either a 0 or 1, and the first two digits of an exchange could not be a 1. At the telephone switching station, the second dialed digit was used to determine if the number was long distance or local. If the number had a 0 or 1 as the second digit, it was long distance, and it was a local call if it was any other number. Thus, since the number 911 was detected by the switching equipment as a special number, it could be routed appropriately. Also, since 911 was a unique number, never having been used as an area code or service code (although at one point GTE used test numbers such as 11911), it fit into the phone system easily.
AT&T announced the selection of 9-1-1 as their choice of the three-digit emergency number at a press conference in the Washington (DC) office of Indiana Rep. J. Edward Roush, who had championed Congressional support of a single emergency number.
In Alabama, Bob Gallagher, president of the independent Alabama Telephone Co. read an article in the Wall Street Journal on Jan. 15, 1968, which reported the AT&T 911 announcement.  Gallaghers competitive spirit motivated him to beat AT&T to the punch by being the first to implement the 911 service, somewhere within the Alabama Telephone Co. territory.  He contacted Robert Fitzgerald, who was Inside State Plant Manager for ATC, who in turn recommended Haleyville, Alabama as the prime site. Gallagher later issued a press release announcing that the 911 service would begin in Haleyville on Feb.16, 1968.  Fitzgerald designed the circuitry, and with the assistance of technicians Jimmy White, Glenn Johnston, Al Bush and Pete Gosa, quickly completed the central office work and installation.
Just 35 days after AT&T's announcement, on February 16, 1968, the first-ever 9-1-1 call was placed by Alabama Speaker of the House Rankin Fite from Haleyville City Hall to U.S. Rep. Tom Bevill (Dem.) at the city's police station. Bevill reportedly answered the phone with "Hello." Attending with Fite was Haleyville mayor James Whitt. At the police station with Bevill was Gallagher and Alabama Public Service Commission director Eugene "Bull" Connor (formerly the Birmingham police chief involved in federal desegregation). Fitzgerald was at the ATC central office serving Haleyville, and actually observed the call pass through the switching gear, as the mechanical equipment clunked out "9-1-1." The phone used to answer the first 911 call, a bright red model, is now in a museum in Haleyville, while a duplicate phone is still in use at the police station. Some accounts of the event claim that, "Later, the two (Bevill and Fite) said they exchanged greetings, hung up and 'had coffee and doughnuts.'"
In 1973, the White House urged nationwide adoption of 911. In 1999, President Bill Clinton signed the bill that designated 911 as the nationwide emergency number.  Even though 9-1-1 was introduced in 1968, the network still does not completely cover some rural areas of the United States and Canada.

# 9-1-1 Emergency Telephone Number Day
9-1-1 Emergency Telephone Number Day was proclaimed, by The proclamation was made to promote the North American universal emergency telephone number 9-1-1.
Until 2001, September 11 was celebrated by many United States communities as "9-1-1 emergency number day" or simply "911 day". The promotional effort was often led by firefighters and the police. After the September 11, 2001 attacks, the reminders of 9-1-1 were dropped in favor of remembrance of the victims of the attacks.
Another way of recognizing the efforts of the people involved in 9-1-1, and  Public Safety Communications in-general, is National Public Safety Telecommunications Week (or as it is commonly called, Dispatchers' Week), which occurs during the second week in April.

# Funding of 9-1-1
9-1-1 and enhanced 9-1-1 are typically funded pursuant to state laws that impose monthly fees on local and wireless telephone customers. Depending on the state, counties and cities may also levy a fee, which may be in addition to, or in lieu of, the state fee. The fees are collected by local exchange and wireless carriers through monthly surcharges on customer telephone bills. The collected fees are remitted to 911 administrative bodies, which may be a statewide 911 board, the state public utility commission, a state revenue department, or local 911 agencies. These agencies disburse the funds to the Public Safety Answering Points for 911 purposes as specified in the various statutes. Telephone companies, including wireless carriers, may be entitled to apply for and receive reimbursements for costs of compliance with federal and state laws requiring that their networks be compatible with 9-1-1 and enhanced 9-1-1.
The amount of the fees vary widely by locality. Fees may range from around $.25 per month to $3.00 per month per line. The average wireless 9-1-1 fee in the United States is around $.72, which is based on the fees for each state as published by the National Emergency Number Association (NENA). Since the monthly fees do not vary by the customer's usage of the network, the fees are considered, in tax terms, as highly "regressive", i.e., the fees disproportionately burden low-volume users of the public switched network (PSN) as compared with high-volume users. Some states cap the number of lines subject to the fee for large multi-line businesses, thereby shifting more of the fee burden to low-volume single-line residential customers or wireless customers.
Congress in 2004 authorized $250,000,000 USD in annual funding for the 9-1-1 program, but actual federal appropriations to state and local 9-1-1 agencies are yet to occur (as of June 2006).

# Locating callers automatically
In over 93% of locations in the United States and Canada, dialing "911" from any telephone will link the caller to an emergency dispatch centercalled a PSAP, or Public Safety Answering Point, by the telecom industrywhich can send emergency responders to the caller's location in an emergency. In some areas enhanced 911 is available, which automatically gives dispatch the caller's location, if available.  Users should never be fooled into thinking that the information the 911 operator has on the caller's location or phone number is accurate.  It is of paramount importance for the caller to verify their location and phone number in order to ensure help gets to the right location.
Dialing 9-1-1 from a mobile phone (Cellular/PCS) in the United States originally reached the state police or highway patrol, instead of the local public safety answering  point (PSAP). The caller had to describe his/her exact location so that the agency could transfer the call to the correct local emergency services. This happens because the exact location of the cellular phone isn't normally transmitted with the voice call.
In 2000 the FCC issued an order requiring wireless carriers to determine and transmit the location of callers who dial 9-1-1. They set up a phased program: Phase I transmitted the location of the receiving antenna for 9-1-1 calls, while Phase II transmitted the location of the calling telephone. The order set up certain accuracy requirements and other technical details, and milestones for completing the implementation of wireless location services. Subsequent to the FCC's order, many wireless carriers requested waivers of the milestones, and the FCC granted many of them. As of mid-2005, the process of Phase II implementation is generally underway, but limited by the complexity of coordination required between wireless carriers, PSAPs, local telephone companies and other affected government agencies, and the limited funding available to local agencies for the conversion of PSAP equipment to display the location data (usually on computerized maps).
These FCC rules require new mobile phones to provide their latitude and longitude to emergency operators in the event of a 911 call. Carriers may choose whether to implement this via GPS chips in each phone, or via triangulation between cell towers. In addition, the rules require carriers to connect 911 calls from any mobile phone, regardless of whether that phone is currently active.  Due to limitations in technology (of the mobile phone, cell phone towers, and PSAP equipment),  a mobile caller's geographical information may not always be available to the local PSAP.  Although there are other ways, in addition to those previously stated, in which to obtain the geographical location of the caller, the caller should try to be aware of the location of the incident for which they are calling.
In the U.S., Federal Communications Commission (FCC) rules require every telephone that can physically access the network to be able to dial 911, regardless of any reason that normal service may have been disconnected (including non-payment). On wired (land line) phones, this usually is accomplished by a "soft" dial tone, which sounds normal, but will only allow emergency calls. Often, an unused and unpublished phone number will be issued to the line so that it will work properly.
If 911 is dialed from a commercial VoIP service, depending on how the provider handles such calls, the call may not go anywhere at all, or it may go to a non-emergency number at the public safety answering point associated with the billing or service address of the caller. Because a VoIP adapter can be plugged into any broadband internet connection, the caller could actually be hundreds or even thousands of miles away from home, yet if the call goes to an answering point at all, it would be the one associated with the caller's address and not the actual location. It may never be possible to accurately pinpoint the exact location of a VoIP user (even if a GPS receiver is installed in the VoIP adapter, it will likely be indoors, and may not be able to get a signal), so users should be aware of this limitation and make other arrangements for summoning assistance in an emergency.
In March 2005, commercial Internet telephony provider Vonage was sued by the Texas attorney general, who alleged that their website and other sales and service documentation did not make clear enough that Vonage's provision of 911 service was not done in the traditional manner.
In May 2005, the FCC issued an Order requiring VoIP providers to offer 9-1-1 service to all their subscribers within 120 days of the Order being published. The order set off anxiety among many VoIP providers, who felt it would be too expensive and require them to adopt solutions that wouldn't support future VoIP products.

# Problems
There are some issues with the assignment of the number 9-1-1.

## Nine-One-One or Nine-Eleven?
When the 9-1-1 system was originally introduced, it was advertised as the "nine-eleven" service. This was changed when some panicked individuals tried to find the "eleven" key on their telephones (seemingly amusing, but it is important to remember that in emergencies people can easily become extremely confused and irrational). Therefore, all references to the telephone number 9-1-1 are now always made as nine-one-one  never as "nine-eleven" per standards outlined by the National Emergency Number Association (NENA). Some newspapers and other media require that references to the phone number be formatted as 9-1-1, also a suggested standard by NENA. Since September 11, 2001, "nine-eleven" is used almost exclusively to refer to the September 11, 2001 attacks, but is also used for the Porsche 911 sports car. In Spanish, 9-1-1 is known as "nueve once", which means "nine-eleven".

## Dialing patterns
In particular, it can cause some dialing-pattern problems in hotels and businesses. Some hotels, for example, have been known to require dialing "91+" to make an outside call. This leads to calls that look like 91+1+301+555+2368. Since this is a valid number, which starts with 911, and is not a call to an emergency service, a timeout becomes necessary on calls dialed literally as 911. Such prefixes are strongly discouraged by telephone companies. This is also part of the reason why no area codes start with a "1": the slightly less troublesome "outside line" prefix of "9+" would then cause the same problem: "9+114+555+2368", for example. Another possible problem is that the international phone code for India is "91", and sometimes calls meant for India end up at the local emergency dispatch office if the caller did not dial the international call prefix 011.
Some businesses also require just a simple "9" to dial out of their network.  This was parodied in an episode of Andy Richter Controls the Universe, where a co-worker laments that her dead colleague dialed 9-1-1 instead of 9-9-1-1. This "less troublesome" prefix can still cause problems, if a caller dials "9+1+XXX+XXX+XXXX" and the 1 button on the tone dial "skips" and sends 2 "1" digits -- again, the number will then start with "9-1-1", and if the PBX "cuts through" 9-1-1 to emergency services (as many do, and many others recommend), this will provide another opportunity for mistaken emergency calling.

## Emergencies across jurisdictions
When a caller dials 9-1-1, the call is routed to the local public safety answering point.  However, if the caller is attempting to notify authorities in another jurisdiction of an emergency in the area, the process can be complicated.  For example, a caller in Dallas, Texas aware of an emergency occurring in Little Rock, Arkansas would have access to 9-1-1 only in Dallas, whose dispatchers may or may not know how to contact the proper authorities in Little Rock.  The publicly posted phone numbers for most police departments in the U.S. are non-emergency numbers that often specifically instruct callers to dial 9-1-1 in case of emergency, which does not resolve the issue for callers outside of the jurisdiction. In the age of both commercial and personal high speed Internet communications, this issue is becoming an increasing problem.
The FBI, however, has combated this problem by listing an on-line directory of all law enforcement agencies in the United States. This directory is available only to agencies with access to the NCIC/NLETS database, but allows dispatchers to quickly locate after-hour numbers for cross-jurisdictional agencies. The query has been named ORION. Not all local law enforcement agencies have access to this directory, however. 

## Media-caused confusion
For many years after the popular TV show Hawaii Five-O finished its run, GTE Hawaiian Tel included a warning in its phone books that in an emergency, people should dial 9-1-1 and not Hawaii Five-O (as some confused tourists had done). The AAA auto club provided a similar warning in its Hawaii Tourbook travelers guidebook.

# International emergency numbers and numbers in other countries
There is no worldwide common emergency number.
Outside of the U.S. and Canada, 911 doesn't work in most countries. Other common emergency numbers are 112 and 999. 911 is used so pervasively in U.S. and Canadian media programming and safety education material, in the case the materials are exported to countries which emergency number is not 911, the countries sometimes had difficulty in educating children not to dial 911 for help.
An example of this is Uruguay, where the emergency number was traditionally 999, but was changed to 911 in 2001 after many cases where people dialed 911 instead of 999 during an emergency. This was due to the popularity in the country of US television programs and movies which routinely mention 911 as the emergency number to dial.
In 1991, the European Union established 1-1-2 as the universal emergency number for all its member states. In most E.U. countries, 1-1-2 is already implemented and can be called toll-free from any telephone or any cellphone. The GSM mobile phone standard designates 1-1-2 as an emergency number, so it will work on such systems even in North America. In the UK and Republic of Ireland, the number is 9-9-9 with 1-1-2 working in parallel. In the UK, the dashes are very rarely used, so the number is almost always written simply 999.

# 9-1-1 in popular culture
- The number's close association with emergencies has led to 911 being used as shorthand for emergency in text messages sent to pagers and mobile phoneshowever, this is often used to tag situations which do not have the life-safety implications that an actual call to 911 implies.
- The hip hop group Public Enemy released a song that was scathingly critical of the 9-1-1 service entitled 911 Is A Joke on their 1990 album Fear of a Black Planet. The song highlighted the poor performance of the 9-1-1 service in predominantly black neighborhoods.
- The Cyndi Lauper album True Colors contains a track entitled 911.
- In an episode of The Simpsons, Homer picks up the phone and says, "Operator, give me the number for 9-1-1!" (As one will see, this is not an isolated incident.) He also receives the "true" emergency phone number of 9-1-2 when he joins the Stonecutters.
- In another episode of The Simpsons, police chief Clancy Wiggum apparently receives a 9-1-1 call at his home during the town lottery, to which he responds, "No, you got the wrong number. This is nine-one....two."
- From 1989 to 1996 CBS aired Rescue 911, a television show which featured host William Shatner and dramatic recreations of actual emergencies and the corresponding response of 9-1-1.
- In the Crazy For You episode of Home Improvement, Tim Allen's Tim Taylor calls the operator and says "Operator - what's the number for 911?" He then tells the operator to "slow down" as he writes it down.
- In the movie The Santa Clause, also with Tim Allen; upon hearing the noise on his roof, Allen's Scott Calvin asks his son if he knows how to dial 9-1-1 to which the son replies, "yeah, 9-1-1."
- On the 1992 "Earthquake!" episode of Saved By The Bell, a character is told to call 911. The character promptly asks, "What's the number?" A similar scene also occurred in Ed,_Edd_n_Eddy.
- In the 1994 film adaptation of Little Rascals, two kids in the gang consider calling the fire department to put out a fire, but decide otherwise when they realize neither of them knows the number for 911. In the scene, the fire department is actually across the street from the pay phone they were using. One of the kids asks someone "What is the number for 911?"
- In the Disney animated movie Hercules, Hercules rescues two children from a cave-in in a gorge (which was actually a staged calamity to lure Hercules into danger), and one of the children can be heard saying; "Someone call IX I I", which are the Roman numerals for 9-1-1.
- The American TV show Reno 9-1-1! Features Lt. Jim Dangle and the escapades of the Reno Sheriff's department on the Comedy Central Channel.