Date: 201701
Local time of day: 1801-2400
Location: LGA.Airport, NY
Flight conditions: VMC
Weather elements / visibility: Turbulence
Aircraft: Medium Large Transport; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground LGA
Second aircraft: A320
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Situational Awareness; Fatigue; Communication Breakdown; Distraction
Second reporter function: Captain; Pilot Flying
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Detector: Automation Air Traffic Control; Person Air Traffic Control
When detected: Taxi
Result: General None Reported / Taken
Contributing factors: Human Factors; Airport; ATC Equipment / Nav Facility / Buildings
Primary problem: Human Factors

Narrative: I was the First Officer (FO) on [the] flight. We landed on 31 from the expressway visual and made the T turnoff. Tower had said make the left turn off at T. I switched the radio to ground and the captain took the ground frequency while I called ramp to get clearance into the gate. After I had come back to ground frequency the captain had not gotten a word in yet as the frequency was congested and there was a lot of traffic. We were still on T at an angle to B. I checked in with ground finally and stated we were off (runway 31) and joining B. Ground said go straight ahead on bravo and hold short of G. There was an Airbus making the turn from A to G. We were told to give way to Airbus and then hold short of F.Ground changed their mind and said Airbus gives way to you; proceed on B and hold short of F. Then ground asked if we were cleared in to the gate. I stated after 2 outbound aircraft out of the alley we were cleared into the gate. They said okay go F and A and hold short of your alley until you can get in. We taxied from B and took a left on F and a second left on A and held short of the alley while a company aircraft exited the alley. After they were clear we turned right into the alley and into the gate. We followed all of these instructions as stated.Upon reaching the gate; the captain received a phone call from the tower stating we did not hold short of the taxiways we were told to on the way in. We in fact held short of G when asked and also held short of F and the ramp as we were told or until we were told otherwise. The controller also said on the phone; according to the captain; that we were originally told to turn left onto B after exiting the runway. If the case; I did not hear nor read back the instruction to turn left onto bravo.I believe we followed the instructions as they were issued. Some factors though that may have contributed to any deviation that occurred according to the controllers could've been misinterpretation of the taxi instructions on our part or ATC forgetting what instructions they gave us. It was the last leg of days of work for me so fatigue was starting to set in. I could have missed an instruction issued by ground and as a result did not read back the correct instructions and was also not corrected by the controller.It is important to listen to all instructions closely as they are given and confirm them if any doubt exists. There were a number of distractions including talking to ground/tower; calling the ramp to find out the status of the gate; completing the after landing flows/checklist; and most importantly keeping a heads up awareness outside the aircraft especially in a designated Hotspot.


Second narrative: During the landing roll out; between 80 and 60 knots; tower commands take 'T or S; your choice' to exit the runway. Before the FO transfers controls I respond to tower that we can take T taxiway; the response I remember was '...left T and contact ground.' As we taxi off the First Officer (FO) announces he is contacting Ops and Ramp on VHF 2 as I monitor VHF 1 for any further commands. I slow my taxi speed and head towards GG taxiway that points straight to the ramp of gate. Before proceeding any further towards the gate I remain on B short of GG and wait for confirmation from the FO that we are cleared in to our ramp. Once we receive word on who to wait for on the ramp the FO returns to VHF 1 and is able to get a word in with ground between the radio traffic and ground commands to 'continue on B hold short of G.' I move a short distance down B taxiway holding short of G; indicated by the 3 amber lights and was blocked by an A320 on G holding short of runway 4. Landing traffic on 31 exits on S taxiway and an Airbus on A taxiway; Ground commands the Aibrus on A taxiway to taxi on G and B in front of me but they wanted to give way to us. Ground commands us to taxi on B and hold short of F without delay. Once I set the parking brake ground asks about if we are cleared into the gate. The FO responds with what ramp stated; 'One out cleared in' but we were both confused because another aircraft had pushed back into the alley; and we asked ramp to clarify if we were cleared in behind the last outbound which he did verify. The next command from ground was to taxi 'F and A hold short of your ramp.' Once the last aircraft exited the FO told ground we were cleared in and I heard ground respond we were cleared in.As passengers were disembarking the Gate agent told me there was an emergency phone call for me. The airport operations supervisor said that I had not complied with any instructions. That I was to taxi off of the runway and make a left onto B taxiway but did not. Later was commanded to hold short of G and did not comply; and entered the Ramp without clearance. Have better coordination with ops; ramp; and ground. Verify that the message ATC is sending is what they are intending to communicate. Remove the need to verify with Ops on ground that gate assignment is correct.


Synopsis: Air carrier flight crew reported that the Tower informed them they had not followed their taxi clearance correctly. However; the flight crew believed they followed it as it was assigned by ATC.