| 1 | HOC | Homac Aviation Services AG | Callsign: Homac, | D | AVCODES |
| 2 | HOC | CHOCTAW TRANSPORT INC | | | SCAC4 |
| 3 | HOCA | HANCOR OF CANADA INC | | | SCAC4 |
| 4 | HOCB | HALCOMB OIL CO | | | SCAC4 |
| 5 | HOCC | HOME OIL CO INC | | | SCAC4 |
| 6 | HOCE | HOC-EXPRESS, INC | | | SCAC1 |
| 7 | HOCE | HOC EXPRESS INC | | | SCAC4 |
| 8 | HOCF | HERSHBERGER OIL COMPANY LLC | | | SCAC4 |
| 9 | HOCG | HOC TRUCKING INC | | | SCAC4 |
| 10 | HOCI | HENRY OIL CO INC | | | SCAC4 |
| 11 | HOCK | HOCKER OIL COMPANY | | | SCAC4 |
| 12 | HOCM | HARBERT OIL COMPANY INC | | | SCAC4 |
| 13 | HOCO | HOKENBROUGH, M D TRUCKING INC | | | SCAC4 |
| 14 | HOCQ | H CARGO LINES | | | SCAC4 |
| 15 | HOCR | HANSEN OIL COMPANY | | | SCAC4 |
| 16 | HOCU | HOEGH CONTAINER LINES | | | PWRC |
| 17 | HOCU | Hoegh Container Lines | | | RSRV |
| 18 | HOCX | Hunt Oil Co. | 1/1943-1/1946 | | NAKINA |
| 19 | HOCX | Head-On Collision Line | added 4/1957; 10/1957-1/1980; eliminated 1/1991 | | NAKINA |
| 20 | HOCX | Head-On Collision Line | added 4/57; 10/57-1/80; eliminated 1/91 | | NRHS |
| 21 | HOCX | *HUNT OIL CO. | | | PWRC |
| 22 | HOCX | *HEAD-ON COLLISION LINE | | | PWRC |
| 23 | HOCX | Head-On Collision Line | | | RSRV |