| 1 | TC | Air Tanzania Corporation | ICAO: ATC, Callsign: Tanzania, IATA Prefix: 197, Name changed to Air Tanzania Company Ltd. ICAO callsign changed from Tango Charlie | EAT | AVCODES |
| 2 | TC | Air Tanzania Company Limited | ICAO: ATC, Callsign: Tanzania, IATA Prefix: 197, Name changed from Air Tanzania Corporation. ICAO callsign changed from Tango Charlie | EAT | AVCODES |
| 3 | TC | Transportes Aéreos de Integración, S.A. (TAISA) | | CR | AVCODES |
| 4 | TC | Air Tanzania Corporation | ICAO: ATC, Callsign: Tango Charlie, IATA Prefix: 197, ICAO callsign changed to Tanzania | EAT | AVCODES |
| 5 | TC | Tennessee Central Ry. Co. | 8/1920-10/1966 | | NAKINA |
| 6 | TC | Tennessee Central Ry. Co. | 4/38-10/66 | | NRHS |
| 7 | TC | *TENNESSEE CENTRAL RR | | | PWRC |
| 8 | TC | *TIMKEN COMPANY | | | PWRC |
| 9 | TC | *TRANS OCEAN LTD. | | | PWRC |
| 10 | TC | TEMPLE & CENTRAL TEXAS RAILWAY INC | | | SCAC4 |
| 11 | TC | Tennessee Central Railway | | USA | TRAFFIC |
| 12 | TC&G | Tucson, Cornelia and Gila Bend R.R. Co. | 7/1923-4/1938 | | NAKINA |
| 13 | TC&G | Tucson, Cornelia and Gila Bend R.R. Co. | Apr-38 | | NRHS |
| 14 | TC&G | TUCSON, CORNELIA & GILA BEND RAILROAD CO. | | | PWRC |
| 15 | TCA | Tropican Air Services | Callsign: Tropicana, | ET | AVCODES |
| 16 | TCA | Tradecraft Nigeria LTd | Callsign: Tradecraft, | WAN | AVCODES |
| 17 | TCA | Tropican Air Services | | | ICAO1 |
| 18 | TCAA | TRANSPORTES CAAR | | | SCAC4 |
| 19 | TCAC | TRACE AIR CARGO | | | SCAC3 |
| 20 | TCAC | TRANSPORTADORA CAS | | | SCAC4 |
| 21 | TCAE | TRANS CONTINENTAL AUTO EXCHANGE INC | | | SCAC3 |
| 22 | TCAF | TRANSCON AIR FREIGHT | | | SCAC3 |
| 23 | TCAG | THOMAS, C A LEASING INC | | | SCAC3 |
| 24 | TCAG | TRANSPORTES CANPERSA | | | SCAC4 |
| 25 | TCAH | TREALMONT CHARTERING INC AFFRETEMEN | | | SCAC4 |
| 26 | TCAI | TWIN CITY AIR FREIGHT PICK UP & DEL | | | SCAC3 |
| 27 | TCAK | TRANSPORTES CAZARES | | | SCAC4 |
| 28 | TCAL | TRANSCONTINENTAL LOGISTICS LLC | | | SCAC4 |
| 29 | TCAM | TRANSPORT CORPORATION OF AMERICA IN | | | SCAC3 |
| 30 | TCAM | TRANSPORT CORPORATION OF AMERICA IN | | | SCAC4 |
| 31 | TCAN | TRANSPORTES CANALES SA DE CV | | | SCAC4 |
| 32 | TCAO | TRICARICO, STEVE TRUCKING | | | SCAC3 |
| 33 | TCAP | TRANS-CAR INC | | | SCAC4 |
| 34 | TCAQ | TRANS CAL MOTOR EXPRESS | | | SCAC3 |
| 35 | TCAR | TRANS-CARRIERS INC | | | SCAC4 |
| 36 | TCAS | TRANSPORTES CLAPAGA S A DE C V | | | SCAC4 |
| 37 | TCAT | TRACTORS & TRUCK INC | | | SCAC3 |
| 38 | TCAU | BLUE BALTIC SHIPPING & TRADING LIMITED | | C | BIC |
| 39 | TCAU | ASIA BRIDGE CONTAINER PTE LTD | | | SCAC3 |
| 40 | TCAU | THUNDER CONTAINERS SHIPPING A V V | | | SCAC4 |
| 41 | TCAV | TECNOLOGIA AVANZADA EN DRENAJE S A | | | SCAC4 |
| 42 | TCAW | TRANS AMERICAN CUSTOMHOUSE BROKERS | | | SCAC4 |
| 43 | TCAX | Transportation Corp. of America | added 4/1974; 1/1975-1/1980; eliminated 4/1991 | | NAKINA |
| 44 | TCAX | Transportation Corp. of America | added 4/1991; eliminated 1/1994 | | NAKINA |
| 45 | TCAX | General Electric Railcar Services Corp. | added 1/1994; eliminated 1/2000 | | NAKINA |
| 46 | TCAX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005 | | NAKINA |
| 47 | TCAX | Transportation Corp. of America | added 4/74; 1/75-1/80; eliminated 4/91 | | NRHS |
| 48 | TCAX | Transportation Corp. of America | added 4/91; eliminated 1/94 | | NRHS |
| 49 | TCAX | General Electric Railcar Services Corp. | added 1/94; eliminated 1/2000 | | NRHS |
| 50 | TCAX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 51 | TCAX | *TRANSPORTATION CORPORATION OF AMERICA | | | PWRC |
| 52 | TCAX | +(NATX) GENERAL ELECTRIC RAIL SERVICES CORPORATION | | | PWRC |
| 53 | TCAX | Transportation Corporation of America | | | RSRV |
| 54 | TCAX | GENERAL ELECTRIC RAILCAR SERVICES C | | | SCAC4 |
| 55 | TCAX | Transportation Corp. of America | | USA | TRAFFIC |
| 56 | TCB | Transporte del Caribe | | | ICAO1 |
| 57 | TCB | Texas Central Business Lines Corp. | added 4/2001; eliminated 10/2001 | | NAKINA |
| 58 | TCB | Texas Central Business Lines Corp. | 7/2005 | | NAKINA |
| 59 | TCB | Texas Central Business Lines Corp. | added 4/2001 | | NRHS |
| 60 | TCB | TEXAS CENTRAL BUSINESS LINES CORP. | | | PWRC |
| 61 | TCB | Texas Central Business Lines Corporation | | | RSRV |
| 62 | TCB | TEXAS CENTRAL BUSINESS LINES CORPOR | | | SCAC4 |
| 63 | TCB | Texas Central Business Lines Corp. | | USA | TRAFFIC |
| 64 | TCBA | TCB TRANSPORTATION INC | | | SCAC3 |
| 65 | TCBB | TRANSCARIBBEAN MARITIME CORP, OLD S | | | SCAC3 |
| 66 | TCBB | TRANSCARIBBEAN MARITIME CORP, OLD S | | | SCAC4 |
| 67 | TCBC | TIBER CARBULK CARRIERS, INC. | | | SCAC3 |
| 68 | TCBC | T C B ASPHALT | | | SCAC4 |
| 69 | TCBD | T C B TRANSPORT LLC | | | SCAC4 |
| 70 | TCBF | TRANSCARIBE FREIGHT CORP | | | SCAC3 |
| 71 | TCBF | TRANSCARIBE FREIGHT CORP | | | SCAC4 |
| 72 | TCBG | TRI-CONTINENTAL TRUCK BROKERAGE INC | | | SCAC3 |
| 73 | TCBG | T COMBUSTIBLES DE CAMARGO SA DE CV | | | SCAC4 |
| 74 | TCBH | TRANSPORT CSSB INC | | | SCAC4 |
| 75 | TCBI | TCB TRANSPORTATION | | | SCAC3 |
| 76 | TCBI | TRANSPORT CLAUDE BENOIT INC | | | SCAC4 |
| 77 | TCBK | TRANSPORT C B | | | SCAC4 |
| 78 | TCBL | T C B LTD | | | SCAC3 |
| 79 | TCBO | TCB TRANSPORTATION INC | | | SCAC4 |
| 80 | TCBP | TCB TRANSPORTERS INC | | | SCAC3 |
| 81 | TCBP | TCB TRANSPORTATION LLC | | | SCAC4 |
| 82 | TCBQ | TRANSPORTES C B | | | SCAC4 |
| 83 | TCBR | TECUMSEH BRANCH CONNECTING RAILROAD | | | PWRC |
| 84 | TCBR | Tecumseh Branch Connecting Railroad | | | RSRV |
| 85 | TCBR | TCB RUSH TRUCKING & MESSENGER SERVI | | | SCAC3 |
| 86 | TCBS | TCB EXPRESS INC | | | SCAC4 |
| 87 | TCBT | TCB TRANSPORTATION INC | | | SCAC3 |
| 88 | TCBU | TITAN CONTAINERS A/S | | DK | BIC |
| 89 | TCBU | TRANS-CARRIBEAN LINES, INC. | | | SCAC3 |
| 90 | TCBU | TRANS CARIBBEAN LINE | | | SCAC4 |
| 91 | TCBV | THREE CIRCLE LOGISTICS LLC | | | SCAC4 |
| 92 | TCBW | TWO C (2C) LOGISTICS INC | | | SCAC4 |
| 93 | TCBX | AIG RAIL SERVICES, INC. | | | PWRC |
| 94 | TCBX | FLAGSHIP RAIL SERVICES LLC | | | SCAC4 |
| 95 | TCBY | Tecumseh Branch Connecting R.R. Co. | added 1/2004; eliminated 4/2004; 7/2005 | | NAKINA |
| 96 | TCBY | TECUMSEH BRANCH CONNECTING RAILROAD CO. | | | PWRC |
| 97 | TCBY | TECUMSEH BRANCH CONNECTING RAILROAD | | | SCAC4 |
| 98 | TCBZ | TRINTON COAL BUCKSKIN MINE | | | PWRC |
| 99 | TCC | Trans Continental Airlines | Callsign: Transcal, | SUD | AVCODES |
| 100 | TCC | Trans Continental Airlines | | | ICAO1 |
