| 1 | HCT | Cathelicopters S.L. | Callsign: Rotorcat, | E | AVCODES |
| 2 | HCTA | HELMS, CHRIS TRANSPORTATION LLC | | | SCAC4 |
| 3 | HCTB | HAT CREEK TRUCK BROKERAGE CORP | | | SCAC4 |
| 4 | HCTC | HAMPTON, CHRIS TRUCKING | | | SCAC4 |
| 5 | HCTD | HIGH COUNTRY TRANSPORTATION INC | | | SCAC4 |
| 6 | HCTG | HACKL, J K TRANSPORTATION SERVICES | | | SCAC4 |
| 7 | HCTI | HITCHCOCK TRUCKING INC | | | SCAC4 |
| 8 | HCTM | HARRIS CAMDEN TERMINAL EQUIPMENT CO | | | SCAC4 |
| 9 | HCTOR | Hector Rail AB | 2004 - | S | svenska-lok.se |
| 10 | HCTOR | Hector Rail AB | | SE | VKM |
| 11 | HCTR | HILL COUNTRY TRUCKING INC | | | SCAC4 |
| 12 | HCTT | HIGH COUNTRY TRANSPORT LTD | | | SCAC4 |
| 13 | HCTU | HAMILTON CONTAINER TERMINAL | | CDN | BIC |
| 14 | HCTU | COMMISSARIAT DE LA MARINE | | | SCAC4 |
| 15 | HCTV | HELICOPTER TRANSPORT SERVICES INC | | | SCAC4 |
| 16 | HCTX | Martin Marietta Corp. | added 4/1990; 1/1994; eliminated 7/1996; 7/2000 (not listed) | | NAKINA |
| 17 | HCTX | Hallett Construction Co. | added 4/1971; 1/1975-1/1980; eliminated 4/1990 | | NAKINA |
| 18 | HCTX | Hallett Construction Co. | added 4/71; 1/75-1/80; eliminated 4/90 | | NRHS |
| 19 | HCTX | Martin Marietta Corp. | added 4/90; 1/94; eliminated 7/96; 7/2000 | | NRHS |
| 20 | HCTX | *HALLETT CONSTRUCTION CO. | | | PWRC |
| 21 | HCTX | *(MMAX) MARTIN MARIETTA CORPORATION | | | PWRC |
| 22 | HCTX | Hallett Construction (Martin Marietta Corporation) | | | RSRV |
