| 8401 | TRGV | TRANSPORTADORA RIO GRANDE SA DE CV | | | SCAC4 |
| 8402 | TRGX | Terminal Grain Corp. | added 7/1974; 1/1975-1/1980; eliminated 7/1993 | | NAKINA |
| 8403 | TRGX | Upper Merion and Plymouth Leasing Co. | added 7/1993; 1/1994; eliminated 4/1996 | | NAKINA |
| 8404 | TRGX | First Union Rail | added 4/1996; 7/2000-7/2005 | | NAKINA |
| 8405 | TRGX | Terminal Grain Corp. | added 7/74; 1/75-1/80; eliminated 7/93 | | NRHS |
| 8406 | TRGX | Upper Merion and Plymouth Leasing Co. | added 7/93; 1/94; eliminated 4/96 | | NRHS |
| 8407 | TRGX | First Union Rail | added 4/96; 7/2000 | | NRHS |
| 8408 | TRGX | *TERMINAL GRAIN CORP. | | | PWRC |
| 8409 | TRGX | +FIRST UNION RAIL [(UMPX) UPPER MERION AND PLYMOUTH LEASING COMPANY] | | | PWRC |
| 8410 | TRGX | Terminal Grain Corporation | | | RSRV |
| 8411 | TRGX | FIRST UNION RAIL | | | SCAC4 |
| 8412 | TRH | Airmark Aviation, Inc. | Callsign: Transtar, | USA | AVCODES |
| 8413 | TRH | Transavia Holland B.V. | IATA: HV, Callsign: Hotel Victor, ICAO callsign changed to Transavia | NL | AVCODES |
| 8414 | TRH | Transavia Holland B.V. | IATA: HV, Callsign: Transavia, ICA designator changed to TRA. ICAO callsign changed from Hotel Victor | NL | AVCODES |
| 8415 | TRH | Turukhan Airlines | Callsign: Turukhan, | RUS | AVCODES |
| 8416 | TRH | Airmark Aviation | | | ICAO1 |
| 8417 | TRHA | TRACE TRUCKING INC | | | SCAC4 |
| 8418 | TRHD | TRANSPORT ROGER HALDE INC | | | SCAC4 |
| 8419 | TRHG | TERRACE HEIGHTS TRUCKING INC | | | SCAC4 |
| 8420 | TRHI | TRX INC | | | SCAC4 |
| 8421 | TRHO | TRANSPORT RAYMOND HUDON | | | SCAC4 |
| 8422 | TRHR | TRANSPORT R H REDIKER 2000 LTEE | | | SCAC4 |
| 8423 | TRHS | TEXAS ROADRUNNER HOTSHOT LLC | | | SCAC4 |
| 8424 | TRHU | TRITON CONTAINER INTERNATIONAL LTD | | BM | BIC |
| 8425 | TRHU | Triton Container International | | | RSRV |
| 8426 | TRI | Executive Flight Operations, Ontario Government | Callsign: Trillium, | CDN | AVCODES |
| 8427 | TRI | Tri State Airlines, Inc. | Callsign: Fire Fox, | USA | AVCODES |
| 8428 | TRI | Ontario Government | | | ICAO1 |
| 8429 | TRI | TRIDON BUS CO INC | | | SCAC4 |
| 8430 | TRI | Triboro Coach | | USA | TRAFFIC |
| 8431 | TRI | Transins Industry | | BG | VKM |
| 8432 | TRIA | TRIANGLE EXPRESS, INC | | | SCAC1 |
| 8433 | TRIA | TRIANGLE EXPRESS INC | | | SCAC4 |
| 8434 | TRIB | TRI CORP TRANSPORTATION LTD | | | SCAC4 |
| 8435 | TRIC | TRANSPORT REFRIGERATION INC | | | SCAC4 |
| 8436 | TRID | TRIAD TRANSPORT INC | | | SCAC4 |
| 8437 | TRIE | TRI-WEST LTD | | | SCAC4 |
| 8438 | TRIG | TRIANGLE GASOLINE COMPANY | | | SCAC4 |
| 8439 | TRIH | TEAM RAHAL INC | | | SCAC4 |
| 8440 | TRII | TRI-TRANSPORTATION CORPORATION | | | SCAC4 |
| 8441 | TRIJ | TRIPLE J TRUCKING | | | SCAC4 |
| 8442 | TRIK | TRAK TRANPORTACIONES SA DE CV | | | SCAC4 |
| 8443 | TRIL | TRI STATE TRUCKING | | | SCAC4 |
| 8444 | TRIM | TRI CITIES TRUCKING ASSOCIATIONS | | | SCAC4 |
| 8445 | TRIM | Tri-County Metropolitan Transportation District of Oregon | Real: TRIMET | USA | TRAFFIC |
| 8446 | TRIN | Trinidad Ry., Inc. | 1/1994-7/2005 | | NAKINA |
| 8447 | TRIN | Trinidad Ry., Inc. | 1/94-7/2000 | | NRHS |
| 8448 | TRIN | TRINIDAD RAILWAY, INC. | | | PWRC |
| 8449 | TRIN | Trinidad Railway | | | RSRV |
| 8450 | TRIN | TRI-B INC | | | SCAC4 |
| 8451 | TRIO | TRI-STATE TRANSPORT INC | | | SCAC4 |
| 8452 | TRIQ | TRI INVESTMENTS INC | | | SCAC4 |
| 8453 | TRIS | TRIMAR TRANS INC | | | SCAC4 |
| 8454 | TRIT | TRINITY | | | SCAC4 |
| 8455 | TRIU | TRITON CONTAINER INTERNATIONAL LTD | | BM | BIC |
| 8456 | TRIU | TRITON CONTAINER INTERNATIONAL INCORPORATED | | | PWRC |
| 8457 | TRIU | Triton Container International | | | RSRV |
| 8458 | TRIU | TRITON CONTAINER INTERNATIONAL LTD | | | SCAC4 |
| 8459 | TRIX | Iowa Public Service Co. | added 7/1975; 1/1980; eliminated 1/1984 | | NAKINA |
| 8460 | TRIX | Midwest Energy Services Co. | added 1/1984 | | NAKINA |
| 8461 | TRIX | Midwest Power Systems | added 1/1994; eliminated 4/1996 | | NAKINA |
| 8462 | TRIX | MidAmerican Energy Co. | added 4/1996; eliminated 4/1999 | | NAKINA |
| 8463 | TRIX | GATX Captial Corp. | added 4/1999; 7/2000; eliminated 1/2002 | | NAKINA |
| 8464 | TRIX | GATX Financial Corp. | added 1/2002; eliminated 1/2003 | | NAKINA |
| 8465 | TRIX | General American Marks Co. | added 1/2003; 7/2005 | | NAKINA |
| 8466 | TRIX | Iowa Public Service Co. | added 7/75; 1/80 | | NRHS |
| 8467 | TRIX | Midwest Power Systems | added 1/94; eliminated 4/96 | | NRHS |
| 8468 | TRIX | MidAmerican Energy Co. | added 4/96; eliminated 4/99 | | NRHS |
| 8469 | TRIX | GATX Captial Corp. | added 4/99; 7/2000 | | NRHS |
| 8470 | TRIX | *TRINIDAD RAILROAD CO. | | | PWRC |
| 8471 | TRIX | *MIDAMERICAN ENERGY CO. [MIDWEST POWER SYSTEMS; IOWA PUBLIC SERVICE CO.] | | | PWRC |
| 8472 | TRIX | +GENERAL AMERICAN MARKS CO. [GATX FINANCIAL CORP.] | | | PWRC |
| 8473 | TRIX | Midwest Energy Services | | | RSRV |
| 8474 | TRIX | GENERAL AMERICAN MARKS COMPANY | | | SCAC4 |
| 8475 | TRIY | TRITON MARINE SUPPLY | | | SCAC4 |
| 8476 | TRIZ | TARMAC INDUSTRIES | | | PWRC |
| 8477 | TRIZ | TRIMODAL INC | | | SCAC4 |
| 8478 | TRJ | AJT Air International | IATA: E9, Callsign: Turjet, IATA Prefix: 766, IATA designator Re-Assigned | RUS | AVCODES |
| 8479 | TRJ | Trans Euro Air | Callsign: High Tide, | GB | AVCODES |
| 8480 | TRJ | Turbo Mega Airways Pvt. Ltd. t/a trujet | IATA: 2T, Callsign: Trujet, Suspended operations on 15 February 2022. | IND | AVCODES |
| 8481 | TRJ | Trans Euro Air | | | ICAO1 |
| 8482 | TRJ | Trelleborg - Rydsgårds Järnväg | 1894 - 1943 | S | svenska-lok.se |
| 8483 | TRJA | TRANSPORTES JUVERA | | | SCAC4 |
| 8484 | TRJB | TRANSPORTE REFRIGERADOS JULIO TADEO | | | SCAC4 |
| 8485 | TRJC | TRANSPORTES JAVIER CANTU BARRAGAN | | | SCAC4 |
| 8486 | TRJD | THOMAS LOGISTICS | | | SCAC4 |
| 8487 | TRJG | TRANSPORTES REFRIGERADOS GUAVAZNE | | | SCAC4 |
| 8488 | TRJH | TROJAN MARITIME INC | | | SCAC4 |
| 8489 | TRJI | TROJAN TRANSPORTATION INC | | | SCAC4 |
| 8490 | TRJM | TRANSPORTES JMP | | | SCAC4 |
| 8491 | TRJO | TRANSPORTES REFRIGERADOS JASLO SA D | | | SCAC4 |
| 8492 | TRJQ | TRANSPORT JACQUES AUGER INC | | | SCAC4 |
| 8493 | TRJR | TRANSPORT JACQUES RICARD ENR | | | SCAC4 |
| 8494 | TRJS | TRANSPORTES JOSE LUIS DELGADO | | | SCAC4 |
| 8495 | TRJT | TROJAN TIRE INC | | | SCAC4 |
| 8496 | TRJV | TIPPET RICHARDSON OVERSEAS MOVING | | | SCAC4 |
| 8497 | TRJW | T R J TRANSPORT | | | SCAC4 |
| 8498 | TRJY | TRANS-MARKETING RESOURCES INC | | | SCAC4 |
| 8499 | TRK | Air Truck Lineas Aereas, SA | IATA: ZH, Callsign: Air Truck, Designator ZH recalled by IATA | E | AVCODES |
| 8500 | TRK | Turkuaz Airlines | IATA: HK, Desinator HK* recalled by IATA | TR | AVCODES |
