| 1 | GCC | General Electric Capital Aviation Services | Callsign: GECAS, | IRL | AVCODES |
| 2 | GCC | GECAS | | | ICAO1 |
| 3 | GCC | GEORGES CREEK & CUMBERLAND RR | | | PWRC |
| 4 | GCCA | GEESE CARTAGE & COURIER LLC | | | SCAC4 |
| 5 | GCCB | GERRARD CATTLE COMPANY INC | | | SCAC4 |
| 6 | GCCD | GLASSCOCK COUNTY CO-OP | | | SCAC4 |
| 7 | GCCF | GENERAL CONVEYOR CO LTD | | | SCAC4 |
| 8 | GCCG | GOLDEN CIRCLE CARTAGE INC | | | SCAC4 |
| 9 | GCCH | GLOBAL CARGO CONNECTION | | | SCAC4 |
| 10 | GCCI | GREAT CANADIAN COACHES INC | | | SCAC4 |
| 11 | GCCJ | GULF CONSOLIDATED CHASSIS POOL LLC | | | SCAC4 |
| 12 | GCCM | GRACE CHARTERING CORPORATION | | | SCAC4 |
| 13 | GCCO | GENERAL CHEMICAL CORPORATION | | | SCAC4 |
| 14 | GCCQ | GCC EQUIPMENT LCC | | | SCAC4 |
| 15 | GCCT | GCC TRANSPORTE SA DE CV | | | SCAC4 |
| 16 | GCCU | GREEN CONTAINERS AB | | DK | BIC |
| 17 | GCCU | CONSTELLATION NAVIGATION | | | SCAC3 |
| 18 | GCCU | GE CAPITAL CONTAINER FINANCE CORP | | | SCAC4 |
| 19 | GCCV | GILBERT TRUCKING INC | | | SCAC4 |
| 20 | GCCX | General American Marks Co. | added 1/2003; 7/2005 | | NAKINA |
| 21 | GCCX | GATX Financial Corp. | added 1/2002; eliminated 1/2003 | | NAKINA |
| 22 | GCCX | GATX Capital Corp. | added 10/1990; 1/1994-7/2000; eliminated 1/2002 | | NAKINA |
| 23 | GCCX | GATX Leasing Corp. | added 7/1990; eliminated 10/1990 | | NAKINA |
| 24 | GCCX | General Cable Corp. | added 10/1963; 7/1965-1/1975; eliminated 7/1978 | | NAKINA |
| 25 | GCCX | Crown Zellerbach Corp. | eliminated 10/1960 | | NAKINA |
| 26 | GCCX | Gaylord Container Division, Crown Zellerbach Corp. | added 1/1960 | | NAKINA |
| 27 | GCCX | Gaylord Container Corp., Division of Crown Zellerbach Corp. | added 7/1956; eliminated 1/1960 | | NAKINA |
| 28 | GCCX | Gaylord Container Corp. | 4/1947-10/1957; eliminated 7/1956 | | NAKINA |
| 29 | GCCX | Gaylord Container Corp. | 1/52-10/57; eliminated 7/56 | | NRHS |
| 30 | GCCX | Gaylord Container Corp., Division of Crown Zellerbach Corp. | added 7/56; eliminated 1/60 | | NRHS |
| 31 | GCCX | Gaylord Container Division, Crown Zellerbach Corp. | added 1/60 | | NRHS |
| 32 | GCCX | Crown Zellerbach Corp. | eliminated 10/60 | | NRHS |
| 33 | GCCX | General Cable Corp. | 7/65-1/75; eliminated 7/78 | | NRHS |
| 34 | GCCX | GATX Leasing Corp. | added 7/90; eliminated 10/90 | | NRHS |
| 35 | GCCX | GATX Capital Corp. | added 10/90; 1/94-7/2000 | | NRHS |
| 36 | GCCX | GENERAL AMERICAN MARKS COMPANY (GATX) (GENERAL CABLE CORP.; CROWN ZELLERBACH CORP.; GAYLORD CONTAINER CORP.0 | | | PWRC |
| 37 | GCCX | General American Marks (GATX Corporation) | | | RSRV |
| 38 | GCCX | GENERAL AMERICAN MARKS COMPANY | | | SCAC4 |
| 39 | GCCX | General American Marks Company (GATX) | | USA | TRAFFIC |
| 40 | GCCY | GCC LOGISTICS SALES LLC | | | SCAC4 |
| 41 | GCCZ | GIBSON COUNTY CO-OP | | | PWRC |