| 1 | UE | Transeuropean Airlines | ICAO: TEP, Callsign: Transeurline, | RUS | AVCODES |
| 2 | UE | Air Euroamerica S.A. (Uair) | | ROU | AVCODES |
| 3 | UE | Nasair Air Service | ICAO: NAS, Callsign: Nasairways, IATA Prefix: 770, | ER | AVCODES |
| 4 | UE | Ultimate Jetcharters, Inc. | ICAO: UJC, Callsign: Ultimate, Name changed to Ultimate Jetcharters LLC dba Ultimate Air Shuttle. IATA designator changed from UI. | USA | AVCODES |
| 5 | UE | Ultimate Jetcharters LLC dba Ultimate Air Shuttle | ICAO: UJC, Callsign: Ultimate, Name changed from Ultimate Jetcharters, Inc. IATA designator changed from UI. | USA | AVCODES |
| 6 | UE | Union Electric Ry. | 1/1946-7/1954 | | NAKINA |
| 7 | UE | Union Electric Ry. | Jan-52 | | NRHS |
| 8 | UE | UNION ELECTRIC RWY. | | | PWRC |
| 9 | UEA | United Eagle Airlines Co Ltd | IATA: EU, Callsign: United Eagle, IATA Prefix: 811, Name changed to Chengdu Airlines | PRC | AVCODES |
| 10 | UEA | Chengdu Airlines | IATA: EU, Callsign: United Eagle, IATA Prefix: 811, Name changed from United Eagle Airlines Co Ltd. ICAO callsign changed from Hibiscus City. | PRC | AVCODES |
| 11 | UEA | United Eagle Airlines | | | ICAO1 |
| 12 | UEBB | Uerikon-Bauma-Bahn | | CH | TRAFFIC |
| 13 | UECI | UNITED EXPRESS COMPANY INC | | | SCAC4 |
| 14 | UECZ | UNION ELEVATOR CO. | | | PWRC |
| 15 | UECZ | Union Elevator Co. | | | RSRV |
| 16 | UED | Air L.A., Inc. | Callsign: Air L-A, | USA | AVCODES |
| 17 | UED | American International Resorts d/b/a Air L.A. | Callsign: Angel Air, | USA | AVCODES |
| 18 | UED | Air LA | | | ICAO1 |
| 19 | UEDB | UNITED ENERGY DISTRIBUTORS INC | | | SCAC4 |
| 20 | UEDL | UNITED EXPRESS DELIVERY LLC | | | SCAC4 |
| 21 | UEE | United Eagle d.o.o. | Callsign: Eagle Slovenia, | SLO | AVCODES |
| 22 | UEE | Uetersener Eisenbahn | | D | TRAFFIC |
| 23 | UEEZ | UNION EQUITY ELEVATOR CO. | | | PWRC |
| 24 | UEEZ | Union Equity Elevator Co. | | | RSRV |
| 25 | UEF | UEF-Eisenbahn-Verkehrsgesellschaft mbH | Gerstetten (UEF = Ulmer Eisenbahnfreunde) | D | privat-bahn.de |
| 26 | UEF | UEF Eisenbahnverkehrsgesellschaft | | DE | VKM |
| 27 | UEFER | Unidad Ejecutora Ferroviaria de la Provincia de Entre Rios | | RA | TRAFFIC |
| 28 | UEFZ | UNION EQUITY | | | PWRC |
| 29 | UEFZ | Union Equity | | | RSRV |
| 30 | UEG | Usedomer Eisenbahngesellschaft GbR | Zinnowitz | D | privat-bahn.de |
| 31 | UEG | Usedomer EisenbahnGbR | | DE | VKM |
| 32 | UEIA | UNITED EXPEDITED INC | | | SCAC4 |
| 33 | UEIC | ULTRALITE ENTERPRISES INC | | | SCAC4 |
| 34 | UEIN | UNDERSTORY ENTERPRISES INC | | | SCAC4 |
| 35 | UEIV | US ENVIRONMENTAL INC | | | SCAC4 |
| 36 | UEJ | United Executive Jet, Inc. | Callsign: Jetcorp, | USA | AVCODES |
| 37 | UEJ | Jetcorp | | | ICAO1 |
| 38 | UEJ | Uppsala - Enköpings Järnväg | 1912 - 1937 | S | svenska-lok.se |
| 39 | UELB | US EXPRESS & LOGISTICS INC | | | SCAC4 |
| 40 | UELC | UNICORN EXPRESS LLC | | | SCAC4 |
| 41 | UELG | US EXPRESS LOGISTICS LLC | | | SCAC4 |
| 42 | UELX | United Equipment Leasing Associates | added 7/1977; 1/1980; eliminated 4/1988 | | NAKINA |
| 43 | UELX | ADM Transportation Co. | added 4/1988; 1/1994-7/2005 | | NAKINA |
| 44 | UELX | United Equipment Leasing Associates | added 7/77; 1/80; eliminated 4/88 | | NRHS |
| 45 | UELX | ADM Transportation Co. | added 4/88; 1/94-7/2000 | | NRHS |
| 46 | UELX | *UNITED EQUIPMENT LEASING ASSOCIATES | | | PWRC |
| 47 | UELX | +ADM TRANSPORTATION COMPANY (ARCHER DANIELS MIDLAND) | | | PWRC |
| 48 | UELX | United Equipment Leasing Associates (Archer Daniels Midland) | | | RSRV |
| 49 | UELX | ADM TRANSPORTATION COMPANY | | | SCAC4 |
| 50 | UELZ | UNITED ELECTRIC COMPANY | | | PWRC |
| 51 | UELZ | Stadtwerke Uelzen | | D | TRAFFIC |
| 52 | UENU | U-EN CORPORATION | | J | BIC |
| 53 | UEQP | ULTIMATE EQUIPMENT | | | SCAC4 |
| 54 | UES | Ues-Avia Aircompany Ltd. | Callsign: Aviasystem, | UA | AVCODES |
| 55 | UES | Ues-Avia Aircompany | | | ICAO1 |
| 56 | UES | Üstra | City: Hannover | D | TRAFFIC |
| 57 | UESC | UNITED EXPEDITED SERVICES CORP | | | SCAC4 |
| 58 | UESN | UNICORN EXPRESS SERVICES INC | | | SCAC4 |
| 59 | UESU | UES INTERNATIONAL (HK) HOLDINGS LIMITED | | PRC | BIC |
| 60 | UESU | UNIT EQUIPMENT SERVICES AG | | | SCAC4 |
| 61 | UESX | Johnstown America Corp. | added 4/2002; 7/2005 | | NAKINA |
| 62 | UESX | JOHNSTOWN AMERICA CORP. | | | PWRC |
| 63 | UESX | Johnston America Corporation | | | RSRV |
| 64 | UESX | JOHNSTOWN AMERICA CORPORATION | | | SCAC4 |
| 65 | UETAK | UeTakeshi Railway | | J | TRAFFIC |
| 66 | UETD | UHI ENERGY TRANSPORTATION LTD | | | SCAC4 |
| 67 | UETN | US EAGLE TRUCKING INC | | | SCAC4 |
| 68 | UETS | URBAN EXPRESS CHARTER | | | SCAC4 |
| 69 | UETU | UES INTERNATIONAL (HK) HOLDINGS LIMITED | | PRC | BIC |
| 70 | UETU | UES INTERNATIONAL (HK) LT | | | SCAC4 |
| 71 | UEU | United European Airlines ( S.C. ) S.R.L. | Callsign: United European, | RO | AVCODES |
| 72 | UEUR | UPS EUROPE SA | | | SCAC4 |
| 73 | UEWI | UNITED ERECTING OF WISCONSIN INC | | | SCAC4 |
| 74 | UEXA | UNA EXPRESS | | | SCAC4 |
| 75 | UEXE | USKO EXPRESS | | | SCAC4 |
| 76 | UEXI | USA EXPRESS INC | | | SCAC4 |
| 77 | UEXR | UNITED EXPRESS | | | SCAC4 |
| 78 | UEXS | UNITED EXPRESS SYSTEM, INC | | | SCAC1 |
| 79 | UEXS | UNITED EXPRESS SYSTEM INC | | | SCAC4 |
