| 1 | TCG | Thai Air Cargo Co., Ltd. | IATA: T2, Callsign: Thai Cargo, IATA Prefix: 284, Designator T2 reinstated by IATA | T | AVCODES |
| 2 | TCG | Thai Air Cargo Co., Ltd. | IATA: T2, Callsign: Thai Cargo, IATA Prefix: 284, Designator T2 recalled by IATA | T | AVCODES |
| 3 | TCG | Transafricaine Air Cargo | IATA: T3, Callsign: Africargo, IATA Prefix: 728, Designator T3 recalled by IATA. | BF | AVCODES |
| 4 | TCG | Thai Air Cargo | IATA: T2 | | ICAO1 |
| 5 | TCG | Tucson, Cornelia and Gila Bend R.R. Co. | 1/1941-1/1994; eliminated 10/1997; 7/2000-7/2005 | | NAKINA |
| 6 | TCG | Tucson, Cornelia and Gila Bend R.R. Co. | 1/52-1/94; eliminated 10/97; 7/2000 | | NRHS |
| 7 | TCG | TUCSON, CORNELIA & GILA BEND RAILROAD COMPANY | | | PWRC |
| 8 | TCG | Tucson, Cornelia and Gila Bend Railroad | | | RSRV |
| 9 | TCG | Tuzi Construzioni Generali | | I | TRAFFIC |
| 10 | TCGA | TOP CHOICE INC | | | SCAC3 |
| 11 | TCGA | TRANS CARGO TEAM | | | SCAC4 |
| 12 | TCGC | TRANS-CARGO INTERNATIONAL CORPORATI | | | SCAC3 |
| 13 | TCGC | TRANSPORTES CEEG | | | SCAC4 |
| 14 | TCGD | TRUCKERS ASSOCIATION OF CHICAGO LLC | | | SCAC4 |
| 15 | TCGE | TRANSPORTES DE CARGA ENSENADA S A D | | | SCAC4 |
| 16 | TCGG | TRI COUNTY CO OPERATIVE OIL ASSOCIA | | | SCAC4 |
| 17 | TCGI | TRANS CARGO INTERSTATE CO | | | SCAC3 |
| 18 | TCGI | TRANSPORT CGSM INC | | | SCAC4 |
| 19 | TCGK | TRAFFIC CONSULTING SERVICES | | | SCAC4 |
| 20 | TCGL | TEAM CAMPBELL LOGISTICS LLC | | | SCAC4 |
| 21 | TCGN | TCG | | | SCAC4 |
| 22 | TCGO | TRANSCARGO UNLIMITED INC | | | SCAC4 |
| 23 | TCGQ | TRANSPORT CARTAGE & DISTR CO INC | | | SCAC3 |
| 24 | TCGS | TRANSMARK CARTAGE SERVICES | | | SCAC4 |
| 25 | TCGU | TRANSPORTS COTTARD-GLENAT CHIMIE | | F | BIC |
| 26 | TCGU | COTTARD TRANSPORTS GLENAT CHIMIE | | | SCAC4 |
| 27 | TCGV | TRANS OCEAN LOGISTICS B V | | | SCAC4 |
| 28 | TCGW | TRANSPORTES CRUZADOS SA DE CV | | | SCAC4 |
| 29 | TCGX | Tri-County Gas, Inc. | added 10/1983; 1/1994; eliminated 7/1996; added 10/1996; eliminated 4/1997 | | NAKINA |
| 30 | TCGX | Williams Energy Ventures, Inc. | added 10/1999; 7/2000; eliminated 4/2002; 7/2005 (not listed) | | NAKINA |
| 31 | TCGX | Tri-County Gas, Inc. | added 10/83; 1/94; eliminated 7/96; added 10/96; eliminated 4/97 | | NRHS |
| 32 | TCGX | Williams Energy Ventures, Inc. | added 10/99; 7/2000 | | NRHS |
| 33 | TCGX | WILLIAMS ENERGY VENTURES, INC. [TRI-COUNTY GAS, INC.] | | | PWRC |
| 34 | TCGX | Tri-County Gas | | | RSRV |
| 35 | TCGY | TRANSPORTES DE CARGA RIO GRANDE SA | | | SCAC4 |
| 36 | TCGZ | COLUMBUS & GREENVILLE RWY | | | PWRC |
| 37 | TCGZ | Columbus and Greenville Railway | | | RSRV |
| 38 | TCGZ | COLUMBUS AND GREENVILLE RAILWAY | | | SCAC4 |
