| 1 | TRE | Trans-Eastern Airlines Ltd. | Callsign: Trans-East, | EAK | AVCODES |
| 2 | TRE | TRINITY RAILWAY EXPRESS | | | PWRC |
| 3 | TRE | Trinity Railway Express | | | RSRV |
| 4 | TRE | Trinity Railway Express | | USA | TRAFFIC |
| 5 | TRE | TOMI - REMONT a.s. | | CZ | VKM |
| 6 | TREB | TRANS EXPRESS LLC | | | SCAC4 |
| 7 | TREB | Trent Barton | | GB | TRAFFIC |
| 8 | TRED | THOR REDERI A/S | | | SCAC4 |
| 9 | TREG | TERRELL TRUCKING LLC | | | SCAC4 |
| 10 | TREJ | TREJO OIL COMPANY INC | | | SCAC4 |
| 11 | TREK | TERAN ENCINAS, MANUEL | | | SCAC4 |
| 12 | TREL | TRANSPORT REAL POIRIER INC | | | SCAC4 |
| 13 | TREN | TALPAR EXPRESS INC | | | SCAC4 |
| 14 | TREP | TRANSPORT EXPRESS INC | | | SCAC4 |
| 15 | TRET | TURNER, R TRUCKING | | | SCAC4 |
| 16 | TRET | Trentino Transporti | City: Trient | I | TRAFFIC |
| 17 | TREU | TRIEST AG GROUP INC | | USA | BIC |
| 18 | TREU | Triest Ag Group,Inc | | | RSRV |
| 19 | TREU | TREFFER TRANSPORT GMBH | | | SCAC4 |
| 20 | TREVI | Trevisan S.r.l. | | IT | VKM |
| 21 | TREVIS | UAB Transrevis | City: Riga | LT | TRAFFIC |
| 22 | TREW | TRI-STAR FREIGHT | | | SCAC4 |
| 23 | TREW | Trentway-Wagar | | CDN | TRAFFIC |
| 24 | TREX | Tetra Technologies, Inc. | added 1/1990; 1/1994; eliminated 4/2000; 7/2000-7/2005 (not listed) | | NAKINA |
| 25 | TREX | Tetra Technologies, Inc. | added 1/90; 1/94; eliminated 4/2000; 7/2000 | | NRHS |
| 26 | TREX | *TRINITY RAILWAY EXPRESS | | | PWRC |
| 27 | TREX | +TETRA TECHNOLOGIES, INC. | | | PWRC |
| 28 | TREX | Tetra Technologies | | | RSRV |
| 29 | TREX | TETRA TECHNOLOGIES, INC. | | | SCAC4 |
| 30 | TREZ | Trencianska Elektricka Zeleznica | | SK | TRAFFIC |
