| 1 | GCM | Comair Flight Services (Pty) Ltd | Callsign: Globecom, | ZA | AVCODES |
| 2 | GCMD | GRAND CENTRAL MARKETING INC | | | SCAC4 |
| 3 | GCMH | GCM TRUCKING INC | | | SCAC4 |
| 4 | GCMI | GRUPO COMERCIAL CM SA DE CV | | | SCAC4 |
| 5 | GCMK | GRAIN | | | SCAC4 |
| 6 | GCML | GARCIA, MINERVA LUIS | | | SCAC4 |
| 7 | GCMN | GRACE MANAGEMENT S A | | | SCAC4 |
| 8 | GCMO | GRAEBEL CLEVELAND MOVERS INC | | | SCAC4 |
| 9 | GCMP | GENCOM TRANSPORTATION, INC | | | SCAC1 |
| 10 | GCMR | GARCIA AMEZCUA, RICARDO | | | SCAC4 |
| 11 | GCMS | GM CARGO | | | SCAC4 |
| 12 | GCMU | SHAANXI GREATROAD INDUSTRIAL CO LTD | | PRC | BIC |
| 13 | GCMU | MORLEY, | | | SCAC4 |
| 14 | GCMV | GRAEBEL/CINCINNA | | | SCAC4 |
| 15 | GCMX | Gulf Coast Chapter—National Railway Historical Society Inc. | 7/2005 (not listed) | | NAKINA |
| 16 | GCMX | Gulf Coast Management Corp. | added 7/1985; eliminated 1/1988 | | NAKINA |
| 17 | GCMX | Garfield Chemical & Manufacturing Corp. | added 4/1957; 10/1957; eliminated 1/1961 | | NAKINA |
| 18 | GCMX | Garfield Chemical & Manufacturing Co. (American Smelting & Refining Co.) | added 11/1934; 7/1935-4/1938 | | NAKINA |
| 19 | GCMX | Garfield Chemical & Manufacturing Co. (American Smelting & Refining Co.) | Apr-38 | | NRHS |
| 20 | GCMX | Garfield Chemical & Manufacturing Corp. | added 4/57; 10/57 | | NRHS |
| 21 | GCMX | Gulf Coast Management Corp. | eliminated 1/88 | | NRHS |
| 22 | GCMX | *GARFIELD CHEMICAL & MANUFACTURING CORP. | | | PWRC |
| 23 | GCMX | *GULF COAST MANAGEMENT CORP. | | | PWRC |
| 24 | GCMX | +NATIONAL RAILWAY HISTORICAL SOCIETY, GULF COAST CHAPTER | | | PWRC |
| 25 | GCMX | Gold Coast Chapter National Railway Historical Society | | | RSRV |
| 26 | GCMX | GULF COAST CHAPTER-NATIONAL RAILWAY | | | SCAC4 |
| 27 | GCMY | GOLD COUNTRY MOVING & STORAGE | | | SCAC4 |
