| 1 | TSO | Transaero Airlines | IATA: UN, Callsign: Transoviet, IATA Prefix: 670, Founded on 28 December 1990. Commenced operations on 05 November 1991. Ceased operations on 25 October 2015. | RUS | AVCODES |
| 2 | TSO | Transaero Airlines | IATA: 4J, IATA designator changed to UN | RUS | AVCODES |
| 3 | TSO | Transaero Airlines | IATA: UN | | ICAO1 |
| 4 | TSO | Tidewater Southern Ry. | 4/1938-7/1954 | | NAKINA |
| 5 | TSO | Tidewater Southern Ry. | 4/38-1/52 | | NRHS |
| 6 | TSO | TIDEWATER SOUTHERN RWY. | | | PWRC |
| 7 | TSO | Travaux de Sud-Ouest | | F | TRAFFIC |
| 8 | TSO | TSO | | FR | VKM |
| 9 | TSOA | TRANSPORTES R SOTELO | | | SCAC4 |
| 10 | TSOA | Transaero | Real: TSO | RUS | TRAFFIC |
| 11 | TSOB | TELFER SHELDON OIL COMPANY | | | SCAC4 |
| 12 | TSOD | TALLE DE SOLDADURA Y FORJA EL BORRA | | | SCAC4 |
| 13 | TSOF | T S A FREIGHTLINES INC | | | SCAC4 |
| 14 | TSOH | TRI-STATE PTEROLEUM PRODUCTS INC | | | SCAC4 |
| 15 | TSOI | TRANSPORTES SOLIS | | | SCAC4 |
| 16 | TSOJ | TRANSPORT SOLUTIONS | | | SCAC4 |
| 17 | TSOL | | City: Lausanne | CH | TRAFFIC |
| 18 | TSOL | TSOL, société du tramway du sud-ouest lausannois SA | | CH | VKM |
| 19 | TSOM | TOWNSEND OIL CO INC | | | SCAC4 |
| 20 | TSON | TRIPLE S TRANSPORTATION INC | | | SCAC4 |
| 21 | TSOSA | Tabor Szynowy Opole SA | | PL | TRAFFIC |
| 22 | TSOSA | Tabor Szynowy” Opole Spółka Akcyjna | | PL | VKM |
| 23 | TSOT | TRI STAR TRANSPORT LLC | | | SCAC4 |
| 24 | TSOU | TONG SENG APPLIED MATERIALS INC. | | RC | BIC |
| 25 | TSOU | TRANSPORTNIYE RESHENIYA CO LTD | | | SCAC4 |
| 26 | TSOW | TRANSPORT SO CAL INC | | | SCAC4 |
| 27 | TSOZ | Tank Solutions | | | RSRV |
| 28 | TSOZ | TANK SOLUTIONS INC | | | SCAC4 |
