| 1 | CTA | Compagnie de Transport Aerien (CTA) | Callsign: CTA, Merged with Balair w.e.f. 01 January 1993. Desigantor RU recalled by IATA | CH | AVCODES |
| 2 | CTA | Trans Caribe, S.A. de C.V. | Callsign: Caribe-Trans, | MEX | AVCODES |
| 3 | CTA | Aero Charter and Transport | Callsign: Char-Tran, | USA | AVCODES |
| 4 | CTA | Compagnie de Transport Aerien (CTA) | IATA: RU, Callsign: CTA, Desigantor RU recalled by IATA | CH | AVCODES |
| 5 | CTA | Aero Charter and Transport | | | ICAO1 |
| 6 | CTA | CHICAGO TRANSIT AUTHORITY | | | PWRC |
| 7 | CTA | CONTINENTAL AIR TRANSPORT CO INC | | | SCAC4 |
| 8 | CTA | Chicago Transit Authority | | USA | TRAFFIC |
| 9 | CTAB | CHITTAMO TRUCK LINES | | | SCAC3 |
| 10 | CTAC | CONTRANS | | | SCAC3 |
| 11 | CTAD | COURT, ARTHUR DESIGNS INC | | | SCAC3 |
| 12 | CTAE | CONNER TRAFFIC ASSOCIATION INC | | | SCAC3 |
| 13 | CTAF | CONNECTICUT AIR FREIGHT INC | | | SCAC3 |
| 14 | CTAG | CORNERSTONE TRANSPORTATION, INC | | | SCAC3 |
| 15 | CTAI | CITY TRANSFER INC | | | SCAC3 |
| 16 | CTAK | COMMERCIAL TRUCK & CRANE | | | SCAC3 |
| 17 | CTAL | CONTINENTAL ATLANTIC LINES INC | | | SCAC3 |
| 18 | CTAN | C2C TRANSPORTATION SERVICES INC | | | SCAC4 |
| 19 | CTAO | COTA TRANSFER & STORAGE | | | SCAC3 |
| 20 | CTAP | COMMERCIAL TRUCK COMPANY (US) INC | | | SCAC3 |
| 21 | CTAP | CROSS COUNTRY TOURS INC | | | SCAC4 |
| 22 | CTAQ | CAROLINA TANK LINES INC | | | SCAC3 |
| 23 | CTAQ | CAROLINA TANK LINES INC | | | SCAC4 |
| 24 | CTAS | CROWLEY TRANSPORTATION SERVICE LLC | | | SCAC4 |
| 25 | CTAT | CONTRACT TRANSPORT INC | | | SCAC3 |
| 26 | CTAT | CONTRACT TRANSPORT INC | | | SCAC4 |
| 27 | CTAU | COOLTAINER NEW ZEALAND LIMITED | | NZ | BIC |
| 28 | CTAU | COOLTAINER SERVICES, LTD | | | SCAC3 |
| 29 | CTAU | OWENS REFRIGERATED FREIGHT LTD | | | SCAC4 |
| 30 | CTAV | CODE THREE AVIATION INC | | | SCAC3 |
| 31 | CTAV | CBC/RADIO-CANADA SOCIETE RADIO CANA | | | SCAC4 |
| 32 | CTAW | CATAWBA TRUCKING CO, INC | | | SCAC3 |
| 33 | CTAX | Coast to Coast Leasing, Inc. | added 4/1969; 4/1970-1/1975; eliminated 7/1977 | | NAKINA |
| 34 | CTAX | Shippers' Car Line Corp. (Service Tank Car Co.) | 1/1941-1/1943 | | NAKINA |
| 35 | CTAX | Service Tank Car Co. | 7/1937-4/1938 | | NAKINA |
| 36 | CTAX | Continental Tank Car Co. | 7/1923-7/1935 | | NAKINA |
| 37 | CTAX | Continental Tank Car Co. | Apr-38 | | NRHS |
| 38 | CTAX | Coast to Coast Leasing, Inc. | added 4/69; 4/70-1/75; eliminated 7/77 | | NRHS |
| 39 | CTAX | *SHIPPERS' CAR LINE CORP [SERVICE TANK CAR CO.; CONTINENTAL TANK CAR CO.] | | | PWRC |
| 40 | CTAX | *COAST TO COAST LEASING, INC. | | | PWRC |
| 41 | CTAY | COURTESY AND YELLOW CABS | | | SCAC3 |
