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.
| IATA | ICAO | Airline | Call sign | Country | Comments |
|---|---|---|---|---|---|
| UEU | United European Airlines | UNITED EUROPEAN | Romania | 2014 [1] | |
| UCG | Uniworld Air Cargo | UNIWORLD | Panama | 2014 [1] | |
| CUH | Urumqi Airlines | LOULAN | China | 2014 [1] | |
| 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 [1] | |
| 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) | |