| 501 | TAMR | TRANSAMERICA | | | SCAC4 |
| 502 | TAMSHUI | Tamshui Bus Company | City: Taipei | RC | TRAFFIC |
| 503 | TAMT | TARANT MARINE INC | | | SCAC4 |
| 504 | TAMT | GD Tamnava Trans d.o.o. | City: Beograd | SR | TRAFFIC |
| 505 | TAMU | TRANSMALLORCA SA | | | SCAC4 |
| 506 | TAMV | TRANS-AMERICA VAN & STORAGE CO | | | SCAC3 |
| 507 | TAMV | TAMMARO, V L TRANSPORT CO INC | | | SCAC4 |
| 508 | TAMW | TAMWAY TRUCKING, INC | | | SCAC3 |
| 509 | TAMW | TRICO TCWIND INC | | | SCAC4 |
| 510 | TAMX | Taminco Methylamines, Inc. | added 4/2007 | | NAKINA |
| 511 | TAMX | TAMINCO METHYLAMINES, INC. | | | PWRC |
| 512 | TAMX | TAMINCO INC | | | SCAC4 |
| 513 | TAMY | TRANS AM LINES INC | | | SCAC3 |
| 514 | TAN | ZanAir Limited | IATA: B4, Callsign: Zanair, Designator B4 recalled by IATA | EAT | AVCODES |
| 515 | TAN | Zanair | | | ICAO1 |
| 516 | TAN | | City: Nantes | F | TRAFFIC |
| 517 | TANA | TANASI & SONS, PASQUALE | | | SCAC3 |
| 518 | TANA | TRANSPORTES DE ANDA Y LOPEZ | | | SCAC4 |
| 519 | TANB | TANGLEN BROS INC | | | SCAC3 |
| 520 | TANC | TRANS CARRIER INC | | | SCAC3 |
| 521 | TAND | TANDEM TRANSPORT CORP | | | SCAC3 |
| 522 | TANE | TAILLON, NICOLE ENR | | | SCAC4 |
| 523 | TANF | TRANSLAREDO | | | SCAC4 |
| 524 | TANG | TANG | | | SCAC3 |
| 525 | TANG | TANGO LOGISTX LLC | | | SCAC4 |
| 526 | TANH | TANNAHILL TRANSPORT LTD/LTEE | | | SCAC3 |
| 527 | TANH | TANNAHILL TRANSPORT LTD/LTEE | | | SCAC4 |
| 528 | TANI | TANDEM LOGISTICS INC | | | SCAC4 |
| 529 | TANK | TANIA TRUCKING | | | SCAC4 |
| 530 | TANK | Transit Authority of Northern Kentucky | City: Cincinnati | USA | TRAFFIC |
| 531 | TANK | SO, GE, TANK SPA | | FR | VKM |
| 532 | TANN | TANO TRUCKING INC | | | SCAC3 |
| 533 | TANN | TREEANN TRUCKING LLC | | | SCAC4 |
| 534 | TANO | TRANSPORTES GUTIERREZ | | | SCAC4 |
| 535 | TANQ | TRANSYS SHIPPING ENTERPRISES CO. | | | SCAC3 |
| 536 | TANR | TANTARA TRANSPORTATION INC | | | SCAC4 |
| 537 | TANS | TRANSPORTATION SERVICES | | | SCAC3 |
| 538 | TANS | TRANSPORTATION SERVICES | | | SCAC4 |
| 539 | TANT | TRAN TECH INC | | | SCAC4 |
| 540 | TANU | TACON GMBH TANK & CONTAINER SERVICES | | D | BIC |
| 541 | TANU | TACON | | | SCAC3 |
| 542 | TANU | TACON GMBH TANK & CONTAINER SERVICE | | | SCAC4 |
| 543 | TANW | TANDY & WOOD TRAVEL AGENCY INC | | | SCAC3 |
| 544 | TANW | TRANSPORTES CANO | | | SCAC4 |
| 545 | TANX | Transitank Car Corp. | added 7/1973; 1/1975; eliminated 7/1979 | | NAKINA |
| 546 | TANX | Transitank Car Leasing Corp. | added 7/1979; 1/1980 | | NAKINA |
| 547 | TANX | Transitank Car Corp. | eliminated 10/1993 | | NAKINA |
| 548 | TANX | TransiTech, Inc. | added 10/1993; 1/1994-7/2000; eliminated 10/2000; 7/2005 (not listed) | | NAKINA |
| 549 | TANX | Transitank Car Corp. | added 7/73; 1/75; eliminated 7/79 | | NRHS |
| 550 | TANX | Transitank Car Leasing Corp. | added 7/79; 1/80 | | NRHS |
| 551 | TANX | Transitank Car Corp. | eliminated 10/93 | | NRHS |
| 552 | TANX | TransiTech, Inc. | added 10/93; 1/94-7/2000; eliminated 10/2000 | | NRHS |
| 553 | TANX | *TRANSITECH, INC. [TRANSITANK CAR LEASING CORP] | | | PWRC |
| 554 | TANX | +TITAN RAIL, INC. | | | PWRC |
| 555 | TANX | Transitank Car Leasing Corporation | | | RSRV |
| 556 | TANX | TITAN RAIL INC | | | SCAC4 |
| 557 | TANY | TAMURA CORPORATION OF AMERICA | | | SCAC4 |
| 558 | TANZ | (IMXZ) INTERMODAL EXPRESS, INC. | | | PWRC |
| 559 | TANZ | Intermodal Express | | | RSRV |
| 560 | TANZ | INTERMODAL EXPRESS, INC. | | | SCAC4 |
| 561 | TAO | Transportes Aeromar, S.A. de C.V. t/a Aeromar | IATA: VW, Callsign: Trans-Aeromar, Ceased operation on 15 February 2023. | MEX | AVCODES |
| 562 | TAO | Transportes Aeromar, S.A. de C.V. | IATA: VW, Callsign: Trans-Aeromar, IATA Prefix: 942, | MEX | AVCODES |
| 563 | TAO | Aeromar | IATA: VW | | ICAO1 |
| 564 | TAOB | TRACO LOGISTICS INC | | | SCAC4 |
| 565 | TAOD | THREE AND ONE TRANSPORT | | | SCAC4 |
| 566 | TAOG | TAYLOR TRUCKING | | | SCAC3 |
| 567 | TAOH | TAI LOGISTICS | | | SCAC4 |
| 568 | TAOI | TAOS INTERSTATE EXPRESS, INC | | | SCAC3 |
| 569 | TAOI | TAOS INTERSTATE EXPRESS | | | SCAC4 |
| 570 | TAOK | TRANSPORTATION INC | | | SCAC3 |
| 571 | TAOL | TOTAL TRANSPORTATION INC | | | SCAC3 |
| 572 | TAOM | TACOMA TRANSLOAD INC | | | SCAC4 |
| 573 | TAOR | TRANSPORT R MONDOR LTEE | | | SCAC3 |
| 574 | TAOS | TRANSPORTATION SYSTEMS | | | SCAC3 |
| 575 | TAOS | TRANSPORTADORA LY C SA DE CV | | | SCAC4 |
| 576 | TAOT | TAYLORS OILFIELD TRUCKING | | | SCAC3 |
| 577 | TAOT | TRANSPORTES TREVINO | | | SCAC4 |
| 578 | TAOU | AGILITY DEFENSE AND GOVERNMENT SERV | | | SCAC4 |
| 579 | TAOW | TAS EXPRESS AMERICA INC | | | SCAC4 |
| 580 | TAP | Transportes Aereos Portugueses, E.P. | IATA: TP, Callsign: Air Portugal, IATA Prefix: 047, Name changed to TAP - Air Portugal | P | AVCODES |
| 581 | TAP | TAP Portugal | IATA: TP, Callsign: Air Portugal, IATA Prefix: 047, Name changed from TAP - Air Portugal | P | AVCODES |
| 582 | TAP | TAP Portugal | IATA: TP | | ICAO1 |
| 583 | TAP | T and P Ry., Inc. | added 1/1992; eliminated 7/1993; 1/1994 (not listed) | | NAKINA |
| 584 | TAP | T and P Ry., Inc. | added 1/92; eliminated 7/93; 1/94 | | NRHS |
| 585 | TAP | RETIRED 11-08-93 (697) ATP [T & P RAILWAY, INC.] | | | PWRC |
| 586 | TAP | | City: Tapolca | H | TRAFFIC |
| 587 | TAPA | TRANSPORTES ALFA | | | SCAC4 |
| 588 | TAPB | TAMPA BAY MOVING SYSTEMS INC | | | SCAC3 |
| 589 | TAPC | TRANSPORTATION COORDINATORS | | | SCAC3 |
| 590 | TAPC | TARGET PACIFIC COAST TRANSPORT LTD | | | SCAC4 |
| 591 | TAPD | TAHOE PICKUP AND DELIVERY SERVICE | | | SCAC3 |
| 592 | TAPD | TRANSPORT Q-TRANS INC | | | SCAC4 |
| 593 | TAPE | TRANSPORTES C & A | | | SCAC4 |
| 594 | TAPF | TAPPANS | | | SCAC3 |
| 595 | TAPF | TAPPANS LIMITED INC | | | SCAC4 |
| 596 | TAPH | TEAM AUTO PROCESSING (DIV OF COOJ) | | | SCAC3 |
| 597 | TAPJ | TAPIA JR TRUCKING | | | SCAC4 |
| 598 | TAPK | TAMO INC | | | SCAC4 |
| 599 | TAPL | TAI PAN LIMOUSINE LTD | | | SCAC3 |
| 600 | TAPM | TAPIA MIRANDA, GERMAN | | | SCAC4 |
