| 1 | UNT | Servicios Aereos Universitarios, S.A. de C.V. | Callsign: Universitario, | MEX | AVCODES |
| 2 | UNT | Servicios Aereos Universitarios | | | ICAO1 |
| 3 | UNTA | UNTAMED ART | | | SCAC4 |
| 4 | UNTC | UNION TRANSFER AND STORAGE COMPANY | | | SCAC4 |
| 5 | UNTH | UNITED TRANSPORT INC | | | SCAC4 |
| 6 | UNTI | UNITEDTRANS LTD | | | SCAC4 |
| 7 | UNTM | UNITED TRANSPORT CORP | | | SCAC4 |
| 8 | UNTN | UNITRANS S A DE C V | | | SCAC4 |
| 9 | UNTO | UNITED TRANSPORTATION LLC | | | SCAC4 |
| 10 | UNTT | UNITEDSABINE LTD | | | SCAC4 |
| 11 | UNTW | UNITED TRANSPORTATION INC, | | | SCAC4 |
| 12 | UNTX | Unitrain, Inc. | added 10/1996; eliminated 4/1998 | | NAKINA |
| 13 | UNTX | MRC Rail Services, LLC | added 4/1998; 7/2000; eliminated 10/2003 | | NAKINA |
| 14 | UNTX | JAIX Leasing Co. | added 10/2003 | | NAKINA |
| 15 | UNTX | Railcar Custom Leasing, LLC | 7/2005; eliminated 7/2007 | | NAKINA |
| 16 | UNTX | Macquarie Rail Inc. | added 7/2007 | | NAKINA |
| 17 | UNTX | Unitrain, Inc. | added 10/96; eliminated 4/98 | | NRHS |
| 18 | UNTX | MRC Rail Services, LLC | added 4/98; 7/2000 | | NRHS |
| 19 | UNTX | *RAILCAR CUSTOM LEASING, LLC [JAIX LEASING CO.; MRC RAIL SERVICES LLC; UNITRAIN, INC.] | | | PWRC |
| 20 | UNTX | +MACQUARIE RAIL, INC. | | | PWRC |
| 21 | UNTX | Unitrain (MRC Rail Services) | | | RSRV |
