| 1 | UTX | UTAir Express | IATA: UR, Callsign: UTAir-Express, IATA Prefix: 434, Ceased operations | RUS | AVCODES |
| 2 | UTX | Avfinity | | | ICAO1 |
| 3 | UTX | Union Tank Car Co. | 8/1920-4/1970; eliminated 7/1973 | | NAKINA |
| 4 | UTX | Union Tank Car Co. | 4/38-4/70; eliminated 7/73 | | NRHS |
| 5 | UTX | UNION TANK CAR CO. | | | PWRC |
| 6 | UTXL | UTXL-UNITED TRAFFIC EXPEDITED LOGIS | | | SCAC4 |
| 7 | UTXT | UNLIMITED TEXTURES A DIVISION OF MO | | | SCAC4 |
