| 1 | TTT | Three T AB | 2001 - | S | svenska-lok.se |
| 2 | TTT | Three T AB | 2001 - | S | TRAFFIC |
| 3 | TTT | Three T AB | | SE | VKM |
| 4 | TTTA | TRI TRUST TRANSPORTATION INC | | | SCAC4 |
| 5 | TTTC | T T T CO INC | | | SCAC4 |
| 6 | TTTD | TRANSPORT T E D | | | SCAC4 |
| 7 | TTTE | T&T TRUCKING, INC | | | SCAC1 |
| 8 | TTTE | TOTAL TEMPERATURE CONTROL TRANSPORT | | | SCAC4 |
| 9 | TTTF | TRENTON TRANSPORTATION SERVICE INC | | | SCAC4 |
| 10 | TTTJ | T & T TRANSPORT SERVICE INC | | | SCAC4 |
| 11 | TTTK | TONEYS TRANSPORTATION LLC | | | SCAC4 |
| 12 | TTTK | Tallina Trammi- ja Trollibussikoondise AS | City: Tallin | EST | TRAFFIC |
| 13 | TTTM | T ANN T TRUCKING INC | | | SCAC4 |
| 14 | TTTN | TITAN TRANSPORT LLC | | | SCAC4 |
| 15 | TTTO | TANTARA TRANSPORTATION CORP | | | SCAC4 |
| 16 | TTTR | TOTAL TRANSPORTATION TRUCKING INC | | | SCAC4 |
| 17 | TTTRA | TT-TRANS, s.r.o. | | SK | VKM |
| 18 | TTTRO | TRADE TRANS TERMINAL SRL | | RO | VKM |
| 19 | TTTT | TRANSPORT TETREAULT INC | | | SCAC4 |
| 20 | TTTU | TRANSPORT INTERNATIONAL CONTAINERS S.A. | | | PWRC |
| 21 | TTTU | Transport International Containers SA | | | RSRV |
| 22 | TTTU | EUROTAINER SAS | | | SCAC4 |
| 23 | TTTW | TENNESSEE TRADERS & TECHNICIANS INC | | | SCAC4 |
| 24 | TTTX | Trailer Train Co. | added 7/1986 | | NAKINA |
| 25 | TTTX | TTX Co. | added 10/1997; 7/2000-7/2005 | | NAKINA |
| 26 | TTTX | Trailer Train Co. | added 7/1986 | | NAKINA |
| 27 | TTTX | TTX Co. | added 10/1997 | | NAKINA |
| 28 | TTTX | Trailer Train Co. | added 7/86 | | NRHS |
| 29 | TTTX | TTX Co. | added 10/97 | | NRHS |
| 30 | TTTX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 31 | TTTX | Trailer Train (TTX Corporation) | | | RSRV |
| 32 | TTTX | TTX COMPANY | | | SCAC4 |
| 33 | TTTY | TWIN TIER TRANSPORT SERVICES INC | | | SCAC4 |
| 34 | TTTZ | *TRANSAMERICAN TRAILER TRANSPORT, INC. | | | PWRC |
| 35 | TTTZ | *PUERTO RICAN MARITIME AUTHORITY | | | PWRC |
| 36 | TTTZ | Puerto Rican Maritime Authority | | | RSRV |
| 37 | TTTZ | PUERTO RICAN MARITIME AUTHORITY | | | SCAC4 |
