| 16301 | CT&S | CAIRO, TRUMAN & SOUTHERN RAILROAD CO. | | | PWRC |
| 16302 | CTA | Compagnie de Transport Aerien (CTA) | Callsign: CTA, Merged with Balair w.e.f. 01 January 1993. Desigantor RU recalled by IATA | CH | AVCODES |
| 16303 | CTA | Trans Caribe, S.A. de C.V. | Callsign: Caribe-Trans, | MEX | AVCODES |
| 16304 | CTA | Aero Charter and Transport | Callsign: Char-Tran, | USA | AVCODES |
| 16305 | CTA | Compagnie de Transport Aerien (CTA) | IATA: RU, Callsign: CTA, Desigantor RU recalled by IATA | CH | AVCODES |
| 16306 | CTA | Aero Charter and Transport | | | ICAO1 |
| 16307 | CTA | CHICAGO TRANSIT AUTHORITY | | | PWRC |
| 16308 | CTA | CONTINENTAL AIR TRANSPORT CO INC | | | SCAC4 |
| 16309 | CTA | Chicago Transit Authority | | USA | TRAFFIC |
| 16310 | CTAB | CHITTAMO TRUCK LINES | | | SCAC3 |
| 16311 | CTAC | CONTRANS | | | SCAC3 |
| 16312 | CTAD | COURT, ARTHUR DESIGNS INC | | | SCAC3 |
| 16313 | CTAE | CONNER TRAFFIC ASSOCIATION INC | | | SCAC3 |
| 16314 | CTAF | CONNECTICUT AIR FREIGHT INC | | | SCAC3 |
| 16315 | CTAG | CORNERSTONE TRANSPORTATION, INC | | | SCAC3 |
| 16316 | CTAI | CITY TRANSFER INC | | | SCAC3 |
| 16317 | CTAK | COMMERCIAL TRUCK & CRANE | | | SCAC3 |
| 16318 | CTAL | CONTINENTAL ATLANTIC LINES INC | | | SCAC3 |
| 16319 | CTAN | C2C TRANSPORTATION SERVICES INC | | | SCAC4 |
| 16320 | CTAO | COTA TRANSFER & STORAGE | | | SCAC3 |
| 16321 | CTAP | COMMERCIAL TRUCK COMPANY (US) INC | | | SCAC3 |
| 16322 | CTAP | CROSS COUNTRY TOURS INC | | | SCAC4 |
| 16323 | CTAQ | CAROLINA TANK LINES INC | | | SCAC3 |
| 16324 | CTAQ | CAROLINA TANK LINES INC | | | SCAC4 |
| 16325 | CTAS | CROWLEY TRANSPORTATION SERVICE LLC | | | SCAC4 |
| 16326 | CTAT | CONTRACT TRANSPORT INC | | | SCAC3 |
| 16327 | CTAT | CONTRACT TRANSPORT INC | | | SCAC4 |
| 16328 | CTAU | COOLTAINER NEW ZEALAND LIMITED | | NZ | BIC |
| 16329 | CTAU | COOLTAINER SERVICES, LTD | | | SCAC3 |
| 16330 | CTAU | OWENS REFRIGERATED FREIGHT LTD | | | SCAC4 |
| 16331 | CTAV | CODE THREE AVIATION INC | | | SCAC3 |
| 16332 | CTAV | CBC/RADIO-CANADA SOCIETE RADIO CANA | | | SCAC4 |
| 16333 | CTAW | CATAWBA TRUCKING CO, INC | | | SCAC3 |
| 16334 | CTAX | Coast to Coast Leasing, Inc. | added 4/1969; 4/1970-1/1975; eliminated 7/1977 | | NAKINA |
| 16335 | CTAX | Shippers' Car Line Corp. (Service Tank Car Co.) | 1/1941-1/1943 | | NAKINA |
| 16336 | CTAX | Service Tank Car Co. | 7/1937-4/1938 | | NAKINA |
| 16337 | CTAX | Continental Tank Car Co. | 7/1923-7/1935 | | NAKINA |
| 16338 | CTAX | Continental Tank Car Co. | Apr-38 | | NRHS |
| 16339 | CTAX | Coast to Coast Leasing, Inc. | added 4/69; 4/70-1/75; eliminated 7/77 | | NRHS |
| 16340 | CTAX | *SHIPPERS' CAR LINE CORP [SERVICE TANK CAR CO.; CONTINENTAL TANK CAR CO.] | | | PWRC |
| 16341 | CTAX | *COAST TO COAST LEASING, INC. | | | PWRC |
| 16342 | CTAY | COURTESY AND YELLOW CABS | | | SCAC3 |
| 16343 | CTB | City Bird | IATA: H2, Callsign: Dream Flight, Ceased operations on 04 October 2001. Designator H2* reinstated by IATA | B | AVCODES |
| 16344 | CTB | City Bird | IATA: H2, Callsign: Dream Flight, Designator H2* recalled by IATA | B | AVCODES |
| 16345 | CTB | Thomas Cook Airlines Balearics S.L. | IATA: H5, Callsign: Sunnyheart, Established in October 2017. Ceased operations on 31 January 2021 | E | AVCODES |
| 16346 | CTB | Captrain Belgium NV | | BE | VKM |
| 16347 | CTBA | CORONADO TRANSPORT INC | | | SCAC3 |
| 16348 | CTBA | C2C TRANSPORTATION INC | | | SCAC4 |
| 16349 | CTBB | COMPLETE TRUCK BROKERAGE INC | | | SCAC3 |
| 16350 | CTBC | CALE TRANSPORT INC | | | SCAC3 |
| 16351 | CTBE | COLONIAL TRANSIT INC | | | SCAC3 |
| 16352 | CTBE | CARIBBEAN TRANSPORT EXPRESS INC | | | SCAC4 |
| 16353 | CTBF | CHRISTIAN TRANSPORTATION | | | SCAC3 |
| 16354 | CTBG | CONDOR TRANSPORT INC | | | SCAC3 |
| 16355 | CTBH | CAROLINA TRUCK BROKERS INC | | | SCAC3 |
| 16356 | CTBH | CLAYTON LOGISTICS LLC | | | SCAC4 |
| 16357 | CTBI | CHRISTIAN TRANSPORT INC | | | SCAC3 |
| 16358 | CTBI | CTB TRANSPORTATION INC | | | SCAC4 |
| 16359 | CTBK | CONTINENTAL TRUCK BROKERS INC | | | SCAC4 |
| 16360 | CTBM | CHAMPION PRODUCTS | | | SCAC4 |
| 16361 | CTBN | CONTE TRANSPORTATION CO | | | SCAC3 |
| 16362 | CTBO | CONTACT TRUCKING CORP | | | SCAC3 |
| 16363 | CTBO | CJT LOGISTICS INC | | | SCAC4 |
| 16364 | CTBP | COLONIAL TAXI CO | | | SCAC3 |
| 16365 | CTBP | CARTERS TRUCKING & BLACKTOPPING INC | | | SCAC4 |
| 16366 | CTBQ | CITY BONDED MESSENGER & TRUCKING SE | | | SCAC3 |
| 16367 | CTBQ | CASTILLO TRANSPORT | | | SCAC4 |
| 16368 | CTBR | CHRISTENSEN BROS TRUCKING INCORPORA | | | SCAC3 |
| 16369 | CTBR | COAST TO COAST AUTO/MARINE TRANSPOR | | | SCAC4 |
| 16370 | CTBS | C T SOUTHERN INC | | | SCAC3 |
| 16371 | CTBT | C T B TRUCKING INC | | | SCAC3 |
| 16372 | CTBT | CTB TRUCK BROKERAGE INC | | | SCAC4 |
| 16373 | CTBU | CONTAINER TRADER LTD. | | BG | BIC |
| 16374 | CTBV | CUSTOM TRANSPORT, INC | | | SCAC3 |
| 16375 | CTBV | CUSTOM TRANSPORT INC | | | SCAC4 |
| 16376 | CTBW | CAROLINA TRANSPORT OF BURGAW INC | | | SCAC4 |
| 16377 | CTBY | CHELATCHIE TRUCKING INC | | | SCAC3 |
| 16378 | CTBY | CRYSTAL CLEAR FREIGHT INC | | | SCAC4 |
| 16379 | CTC | Corporacion Ejecutiva de Transporte Aereo, S.A. de C.V. | Callsign: Corp Ejecutiva, | MEX | AVCODES |
| 16380 | CTC | C T C Air, S.A. | IATA: MW, Callsign: CTC, Designator MW recalled by IATA | E | AVCODES |
| 16381 | CTC | CENTER FOR TRANSPORTATION | | | PWRC |
| 16382 | CTC | CTC (Compagnie de Transports de Céréales | | FR | VKM |
| 16383 | CTCA | CTC TRANSPORTATION INC | | | SCAC3 |
| 16384 | CTCA | COLUMBIA TECHNOLOGIES LLC | | | SCAC4 |
| 16385 | CTCC | COASTAL CAROLINA CARRIERS INC | | | SCAC3 |
| 16386 | CTCD | CORONA TRUCKING CO INC | | | SCAC3 |
| 16387 | CTCF | CITICAR LIMITED | | | SCAC3 |
| 16388 | CTCG | CARTER, CHARLES H & SON INC | | | SCAC3 |
| 16389 | CTCG | CTC LOGISTICS (L A) INC | | | SCAC4 |
| 16390 | CTCH | CATTLE COACHES, INC | | | SCAC3 |
| 16391 | CTCH | CRITICAL CHOICE INCORPORATED | | | SCAC4 |
| 16392 | CTCI | COAST TRANSFER CO INC | | | SCAC3 |
| 16393 | CTCJ | CENTRAL CONNECTICUT LIMOUSINE | | | SCAC3 |
| 16394 | CTCJ | CAYTRANS BBC LLC | | | SCAC4 |
| 16395 | CTCK | CAN-2 TRUCKING INC | | | SCAC4 |
| 16396 | CTCL | CARROLL TRANSPORT COMPANY | | | SCAC3 |
| 16397 | CTCL | CT TECH INC | | | SCAC4 |
| 16398 | CTCN | COLLIER TRUCKING COMPANY INC | | | SCAC3 |
| 16399 | CTCN | CUT TECHNOLOGIES CANADA LTD | | | SCAC4 |
| 16400 | CTCO | CORE TRUCKING CO INC | | | SCAC3 |
