| 1 | GMH | Hughes Aircraft Company | Callsign: Hughes Express, | USA | AVCODES |
| 2 | GMH | Hughes Aircraft Company | | | ICAO1 |
| 3 | GMHL | GLEN MILLS HOME HEATING OIL | | | SCAC4 |
| 4 | GMHM | GLOBAL MARINE SHIP MANAGEMENT CO LT | | | SCAC4 |
| 5 | GMHN | GMR HORN LLC | | | SCAC4 |
| 6 | GMHT | GMH TRANS | | | SCAC4 |
| 7 | GMHX | Holland M Bar D | added 1/2003; 7/2005; eliminated 7/2009 | | NAKINA |
| 8 | GMHX | General Leasing Corp. | added 4/2000; 7/2000; eliminated 1/2003 | | NAKINA |
| 9 | GMHX | General Leasing Corp. | added 4/2000; 7/2000 | | NRHS |
| 10 | GMHX | HOLLAND M BAR D (GENERAL AMERICAN MARKS COMPANY; GENERAL LEASING CORP.) | | | PWRC |
| 11 | GMHX | General American Marks (GATX Corporation) | | | RSRV |
| 12 | GMHX | HOLLAND M BAR D | | | SCAC4 |
