| 1 | TRA | Transavia | IATA: HV, Callsign: Transavia, IATA Prefix: 979, | NL | AVCODES |
| 2 | TRA | Basiq Air | IATA: HV, Merged back into Transavia. Low cost subsidary of Transavia | NL | AVCODES |
| 3 | TRA | Trans Air, Inc. | Callsign: Trans Cab, | USA | AVCODES |
| 4 | TRA | Transavia Holland B.V. | IATA: HV, Callsign: Transavia, | NL | AVCODES |
| 5 | TRA | Transavia Holland | IATA: HV | | ICAO1 |
| 6 | TRA | TENNESSEE RAILROAD CO. | | | PWRC |
| 7 | TRA | | | RC | TRAFFIC |
| 8 | TRAA | TRANSPORTES AMERICANOS S A DE C V | | | SCAC4 |
| 9 | TRABANT | Trabant | | D | TRAFFIC |
| 10 | TRAC | ONE TO THREE (1 TO 3) TRADE CO LLC | | | SCAC4 |
| 11 | TRACC | Traccion Rail s.l. | | ES | VKM |
| 12 | TRACK | ON-TRACK, s.r.o. | | CZ | VKM |
| 13 | TRACKLESS | Trackless Transit | | US-NJ | TRAFFIC |
| 14 | TRAD | TRADE CARRIER | | | SCAC1 |
| 15 | TRAD | TRIAD TRANSPORTATION INC | | | SCAC4 |
| 16 | TRADB | Traditionsbus Berlin | | D | TRAFFIC |
| 17 | TRAF | TRANSPORTES REALIZA S A | | | SCAC4 |
| 18 | TRAG | TRADING POST | | | SCAC4 |
| 19 | TRAH | TRANSPORTES AGUIRRE | | | SCAC4 |
| 20 | TRAI | TRIPLE A TRANSPORT INC | | | SCAC4 |
| 21 | TRAIL | Transrail Freight | | GB | TRAFFIC |
| 22 | TRAIN | Train Rental International | | EU | TRAFFIC |
| 23 | TRAK | Trakcia AD / Тракция АД | | BG | VKM |
| 24 | TRAKC | TRAKCE A.S. Spółka Akcyjna Oddzial w Polsce | | PL | VKM |
| 25 | TRAL | TRANSYSTEMS LLC | | | SCAC4 |
| 26 | TRAM | American Refrigerator Transit Co. | added 10/1961; eliminated 7/1962 | | NAKINA |
| 27 | TRAM | AMERICAN REFRIGERATOR TRANSIT CO. | | | PWRC |
| 28 | TRAM | TRANSMAXX | | | SCAC4 |
| 29 | TRAME | TRAMESA S.A | | ES | VKM |
| 30 | TRAMO | TRAMO RAIL, a.s. | | CZ | VKM |
| 31 | TRAN | TRANSCON LINES | | | PWRC |
| 32 | TRAN | TRANSOCEAN MARITIME AGENCIES SA | | | SCAC4 |
| 33 | TRANS | TRANSPORTSERVIS, spol. s r.o. | | CZ | VKM |
| 34 | TRANSCO | TransCo | | FAN | TRAFFIC |
| 35 | TRANSGOR | Transgór Spółka Akcyjna – przedsiębiorstwo transportowe z Mysłowic | | PL | TRAFFIC |
| 36 | TRANSKOM | Transkom s.j. | City: Piekary Śląskie | PL | TRAFFIC |
| 37 | TRANSLUB | Przedsiębiorstwo Transportowe Translub sp. z o.o. | | PL | TRAFFIC |
| 38 | TRANSLUD | TRANSLUD Przewozy Autokarowe Jan Domosławski | | PL | TRAFFIC |
| 39 | TRANSMAC | Transportes Urbanos de Macau | | | TRAFFIC |
| 40 | TRANSN | Transports Publics Neuchâtelois | | CH | TRAFFIC |
| 41 | TRAP | TRANSPORT SERVICE CO | | | SCAC4 |
| 42 | TRAPL | Trakcja S.A. | | PL | VKM |
| 43 | TRAQ | TRANSPORTERS | | | SCAC4 |
| 44 | TRAR | TRANSPORTES REFRIGERADOS ARAMBURO S | | | SCAC4 |
| 45 | TRAS | TRANSCO SHIPPING (USA) INC | | | SCAC4 |
| 46 | TRAS | Trasfeimer Trasporti Ferroviari Innovativi Meridionali S.p.A. | | IT | VKM |
| 47 | TRASK | TRATEC SK s.r.o | Real: TRA | SK | TRAFFIC |
| 48 | TRAU | ASSOCIATED TRANSPORT LINE | | | PWRC |
| 49 | TRAU | Associated Transport Line | | | RSRV |
| 50 | TRAU | ASSOCIATED TRANSPORT LINE | | | SCAC4 |
| 51 | TRAV | TRANSPORTES VIRAMONTES | | | SCAC4 |
| 52 | TRAV | Transavia | | | TRAFFIC |
| 53 | TRAX | Terminal Refining Co. (Keystone Oil & Manufacturing Co.) | 8/1920 | | NAKINA |
| 54 | TRAX | American Refrigerator Transit Co. | added 4/1954; 10/1957-4/1970; eliminated 7/1970 | | NAKINA |
| 55 | TRAX | Railtex Corp. | added 7/1978 | | NAKINA |
| 56 | TRAX | Railtex Inc. | 1/1980 | | NAKINA |
| 57 | TRAX | Railtex Corp. | 1/1994 | | NAKINA |
| 58 | TRAX | Railtex Inc. | 7/2000-7/2005 | | NAKINA |
| 59 | TRAX | American Refrigerator Transit Co. | added 4/54; 10/57-4/70; eliminated 7/70 | | NRHS |
| 60 | TRAX | Railtex Corp. | added 7/78 | | NRHS |
| 61 | TRAX | Railtex Inc. | Jan-80 | | NRHS |
| 62 | TRAX | Railtex Corp. | Jan-94 | | NRHS |
| 63 | TRAX | Railtex Inc. | Jul-00 | | NRHS |
| 64 | TRAX | *KEYSTONE OIL & MANUFACTURING CO. [TERMINAL REFINING CO.] | | | PWRC |
| 65 | TRAX | +RAILTEX, INC. [AMERICAN REFRIGERATOR TRANSIT CO.] | | | PWRC |
| 66 | TRAX | Railtex | | | RSRV |
| 67 | TRAX | RAILTEX, INC. | | | SCAC4 |
| 68 | TRAY | TRANSPORTADORA DE COSS S A DE C V | | | SCAC4 |
