| 10201 | TTWX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 10202 | TTWX | Trailer Train Co. (flush deck flat cars equipped with movable foldaway container pedestals and collapsible hitches, capable of handling 2 45' dry trailers with 36"" kingpin spacing, at either lift-on/lift-off or end loading facilities using portable bridge plates provided by carrier. | added 10/1982; 7/1985 | | NAKINA |
| 10203 | TTWX | Trailer Train Co./TTX Co. (flush deck flat cars equipped with movable foldaway container pedestals and collapsible hitches, capable of handling 2 45' dry trailers with 36"" kingpin spacing, at either lift-on/lift-off or end loading facilities using portable bridge plates provided by carrier, and/or various combinations of 20' and 40' containers. In TOFC service the load limit is 130000 lbs. (65000 lbs. per hitch). In COFC service the load limit is approximately 150000 lbs., depending on the light weight of | 10/1991-7/2000 | | NAKINA |
| 10204 | TTWX | Trailer Train Co. | added 10/82; eliminated 1/92 | | NRHS |
| 10205 | TTWX | TTX Co. | added 1/92 | | NRHS |
| 10206 | TTWX | TTX Co. (flush deck flat cars equipped with movable foldaway container pedestals and collapsable hitches, capable of handling 2 45' dry trailers with 36" kingpin spacing, at either lift on/lift off or end loading facilities using portable bridge plates provided by carrier, and/or various combinations of 20' and 40' containers. In TOFC service the load limit is 130000 lbs. (65000 lbs. per hitch). In COFC service the load limit is approximately 150000 lbs., depending on the light weight of the car) | 1/94-7/2000 | | NRHS |
| 10207 | TTWX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 10208 | TTWX | Trailer Train (TTX Corporation) | | | RSRV |
| 10209 | TTWX | TTX COMPANY | | | SCAC4 |
| 10210 | TTWZ | CANADIAN NATIONAL | | | PWRC |
| 10211 | TTWZ | Canadian National Railway | | | RSRV |
| 10212 | TTWZ | CANADIAN NATIONAL RAILWAYS | | | SCAC4 |
| 10213 | TTX | Air Team A.S. | IATA: 8W, Callsign: Air Team, Designator 8W* recalled by IATA | N | AVCODES |
| 10214 | TTX | Den Sivile Flyskole | Callsign: Sparrow, | N | AVCODES |
| 10215 | TTX | Extraordin Air Aviation and Charter | Callsign: Twister, | USA | AVCODES |
| 10216 | TTX | Thurber Tank Line Co. | 7/1930-7/1932 | | NAKINA |
| 10217 | TTX | Texas Pacific Coal & Oil Co. | 7/1935-1/1946 | | NAKINA |
| 10218 | TTX | Trailer Train Co. | added 4/1956; 10/1957-1/1980; eliminated 1/1992 | | NAKINA |
| 10219 | TTX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 10220 | TTX | Trailer Train Co. (not defined) | added 4/1956; 10/1957-4/1961 | | NAKINA |
| 10221 | TTX | Trailer Train Co. (FC flat cars equipped with hitches, bridge plates and safety chains for the transportation of trailers) | 4/1963-7/1965 | | NAKINA |
| 10222 | TTX | Trailer Train Co. (FC flat cars equipped with hitches and bridge plates for the transportation of trailers) | 10/1966-1/1980 | | NAKINA |
| 10223 | TTX | Trailer Train Co./TTX Co. (flat cars equipped with collapsable hitches for the transportation of trailers) | 7/1985-7/2000 | | NAKINA |
| 10224 | TTX | Texas Pacific Coal and Oil Co. | Apr-38 | | NRHS |
| 10225 | TTX | Trailer Train Co. | 10/57-7/65 | | NRHS |
| 10226 | TTX | Trailer Train Co. (FC flat cars equipped with hitches and bridge plates for the transportation of trailers) | 10/66-1/80 | | NRHS |
| 10227 | TTX | Trailer Train Co. | eliminated 1/92 | | NRHS |
| 10228 | TTX | TTX Co. | added 1/92 | | NRHS |
| 10229 | TTX | TTX Co. (flat cars equipped with collapsable hitches for the transportation of trailers) | 1/94-7/2000 | | NRHS |
| 10230 | TTX | *THURBER TANK LINE CO. | | | PWRC |
| 10231 | TTX | *TEXAS PACIFIC COAL & OIL CO. | | | PWRC |
| 10232 | TTX | +TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 10233 | TTX | Trailer Train (TTX Corporation) | | | RSRV |
| 10234 | TTX | TTX COMPANY | | | SCAC4 |
| 10235 | TTX | | | USA | TRAFFIC |
| 10236 | TTXA | TRANSPORT TRANS XLINE INC | | | SCAC4 |
| 10237 | TTXD | TAMPA TRANSPORTATION & LOGISTICS LL | | | SCAC4 |
| 10238 | TTXF | TM TRUCKING | | | SCAC4 |
| 10239 | TTXH | THREE T TRUCKING LLC | | | SCAC4 |
| 10240 | TTXJ | TRANSPLACE TEXAS LP (INTERMODAL FLE | | | SCAC4 |
| 10241 | TTXK | TRANSPLACE TEXAS LP (LOWELL) | | | SCAC4 |
| 10242 | TTXM | TRANSPLACE TEXAS, LP (DEDICATED FLE | | | SCAC4 |
| 10243 | TTXO | TROY'S TRANSPORT INC | | | SCAC4 |
| 10244 | TTXP | TORO TRANSPORT EXPRESS | | | SCAC4 |
| 10245 | TTXR | TRANSCISCO TEXAN RAILWAY INC. | | | PWRC |
| 10246 | TTXS | T & T EXPRESS INC | | | SCAC4 |
| 10247 | TTXX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 10248 | TTXX | TTX COMPANY | | | SCAC4 |
| 10249 | TTY | Thai Tours And Trans Airways Co., Ltd | Callsign: Triple Tour, | T | AVCODES |
| 10250 | TTYB | THUNDERBIRD TRUCKING | | | SCAC4 |
| 10251 | TTYD | TNT TRANSPORTATION LC | | | SCAC4 |
| 10252 | TTYE | TASI TRANSPORTATION | | | SCAC4 |
| 10253 | TTYF | TRUST TRANSPORTATION | | | SCAC4 |
| 10254 | TTYG | T TWO (T2) SUPPLY CHAIN SOLUTIONS L | | | SCAC4 |
| 10255 | TTYL | T & T LOGISTICS | | | SCAC4 |
| 10256 | TTYN | TRANSPORTES INTERNACIONALES TYN | | | SCAC4 |
| 10257 | TTYP | T & T EXPRESS INC | | | SCAC4 |
| 10258 | TTYQ | TAITA TRANS INC | | | SCAC4 |
| 10259 | TTYW | T-TRADER ELEVEN LTD | | | SCAC4 |
| 10260 | TTYX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 10261 | TTYX | TTX COMPANY | | | SCAC4 |
| 10262 | TTZ | Transair Limited | IATA: TZ, Callsign: Transair, Formed by the merger of Central Northern Airways and Arctic Wings in 1956. Merged into Pacific Western Airlines on 01 November 1979. | CDN | AVCODES |
| 10263 | TTZ | TILCON TOMASSO | | | PWRC |
| 10264 | TTZA | TRANS-TRADE INC | | | SCAC4 |
| 10265 | TTZC | TOTAL PETROLEUM LLC | | | SCAC4 |
| 10266 | TTZD | TRANSPORTES THREE (3) DIAMANTES | | | SCAC4 |
| 10267 | TTZE | TWO TWO ZERO EIGHT EIGHT ONE TWO (2 | | | SCAC4 |
| 10268 | TTZG | TOTAL LEASING & LOGISTICS | | | SCAC4 |
| 10269 | TTZH | T-TRADER SEVEN LTD | | | SCAC4 |
| 10270 | TTZI | TWO TWO ZERO FIVE ONE THREE FOUR (2 | | | SCAC4 |
| 10271 | TTZJ | T-TRADER NINE LTD | | | SCAC4 |
| 10272 | TTZK | TRYSLYN TRANSPORTATION INC | | | SCAC4 |
| 10273 | TTZL | TRANSI TAINER TERMINALS LTD | | | SCAC4 |
| 10274 | TTZN | TRANS-TRADE INC | | | SCAC4 |
| 10275 | TTZS | T & T EXPRESS | | | SCAC4 |
| 10276 | TTZT | TESTED & TRIED TRUCKING CO INC | | | SCAC4 |
| 10277 | TTZV | TRANSPORTES ZAVE | | | SCAC4 |
| 10278 | TTZW | TERRY TRUCKING COMPANY | | | SCAC4 |
| 10279 | TTZX | Trailer Train Co. | eliminated 1/1992 | | NAKINA |
| 10280 | TTZX | TTX Co. | added 1/1992; 1/1994-7/2005 | | NAKINA |
| 10281 | TTZX | Trailer Train Co./TTX Co. (flat cars equipped with bulkheads and centre beams with tie-down systems for lumber loading) | 10/1991-1/1994 | | NAKINA |
| 10282 | TTZX | TTX Co. (flat cars equipped with bulkheads and centre beams with tie-down systems for lumber loading, equipped with end of car cush.) | 7/2000 | | NAKINA |
| 10283 | TTZX | Trailer Train Co. | eliminated 1/92 | | NRHS |
| 10284 | TTZX | TTX Co. | added 1/92 | | NRHS |
| 10285 | TTZX | TTX Co. (flat cars equipped with bulkheads and centre beams with tie-down systems for lumber loading) | Jan-94 | | NRHS |
| 10286 | TTZX | TTX Co. (flat cars equipped with bulkheads and centre beams with tie-down systems for lumber loading, equipped with end of car cush.) | Jul-00 | | NRHS |
| 10287 | TTZX | TTX COMPANY {TRAILER TRAIN COMPANY} | | | PWRC |
| 10288 | TTZX | Trailer Train (TTX Corporation) | | | RSRV |
| 10289 | TTZX | TTX COMPANY | | | SCAC4 |
| 10290 | TTZY | TWO TWO FOUR NINE NINE ZERO SEVEN ( | | | SCAC4 |
| 10291 | TTZZ | FLEXI-VAN LEASING INC | | | SCAC4 |
| 10292 | TU | Tunisair | ICAO: TAR, Callsign: Tunair, IATA Prefix: 199, | TN | AVCODES |
| 10293 | TUA | Turkmenistan Airlines | IATA: T5, Callsign: Turkmenistan, IATA Prefix: 542, Designator T5 reinstated by IATA. ICAO designator changed from AKH | TM | AVCODES |
| 10294 | TUA | Turkmenhovayollary | | | ICAO1 |
| 10295 | TUA | Turkmenistan Airlines | | TM | TRAFFIC |
| 10296 | TUAA | TALERO USED AUTO PARTS | | | SCAC4 |
| 10297 | TUAE | TURN A ROUND EXPRESS LLC | | | SCAC4 |
| 10298 | TUAG | TRANSPORTES UNIDOS ARECHIGA S A DE | | | SCAC4 |
| 10299 | TUAG | MARTI AG Tunnelbau | | CH | TRAFFIC |
| 10300 | TUAH | TRANSPORT DAVE MICHAUD | | | SCAC4 |
