| 1 | TWR | Transworld Airfreighters | Callsign: Transworld, AOC revoked. | JOR | AVCODES |
| 2 | TWR | Tokyo Waterfront Area Rapid Transit | City: Tokyo, Rinkai Line. Third-sector railway in Tokyo, Japan, connecting Tokyo to the artificial islands of Aomi and Odaiba in Tokyo Bay. | J | TRAFFIC |
| 3 | TWRA | TRUSTWORTHY TRANSPORTATION LLC | | | SCAC4 |
| 4 | TWRC | TOWER TRUCK LINES INC | | | SCAC4 |
| 5 | TWRD | TRIANGLE WAREHOUSE INC | | | SCAC4 |
| 6 | TWRE | TWO RIVERS CANOE & TACKLE | | | SCAC4 |
| 7 | TWRL | TRANSWORLD LINE INC | | | SCAC4 |
| 8 | TWRN | TOWER TRANSPORT INC | | | SCAC4 |
| 9 | TWRO | TIMS TOWING & RECOVERY | | | SCAC4 |
| 10 | TWRQ | TWO SISTERS TRUCKING LLC | | | SCAC4 |
| 11 | TWRS | TRANSWORLD TRANSPORTATION SERVICES | | | SCAC4 |
| 12 | TWRT | TWO RIVERS TIMBER CO INC | | | SCAC4 |
| 13 | TWRU | PEACOCK CONTAINER PTE. LTD. | | SGP | BIC |
| 14 | TWRU | GEHOLO BV | | | SCAC4 |
| 15 | TWRY | Tradewater Ry. Co. | added 4/1982; 1/1994; eliminated 4/1995 | | NAKINA |
| 16 | TWRY | Western Kentucky Ry., L.L.C. | added 4/1995; eliminated 7/2003; 7/2005 | | NAKINA |
| 17 | TWRY | Tradewater Ry. Co. | added 4/82; 1/94; eliminated 4/95 | | NRHS |
| 18 | TWRY | Western Kentucky Ry., L.L.C. | added 4/95 | | NRHS |
| 19 | TWRY | WESTERN KENTUCKY RWY., LLC [TRADEWATER RAILWAY CO.] | | | PWRC |
| 20 | TWRY | Tradewater Railway | | | RSRV |
| 21 | TWRY | TRUSTWORTHY TRANSPORTATION INC | | | SCAC4 |
