| 1 | SCR | Si-Chang Flying Service Co., Ltd. | Callsign: Sichart, Ceased operations | T | AVCODES |
| 2 | SCR | Silver Cloud Air GmbH | Callsign: Silver Cloud, | D | AVCODES |
| 3 | SCR | Si-Chang Flying Service | | | ICAO1 |
| 4 | SCR | SYDNEY COAL RAILWAY | | | PWRC |
| 5 | SCR | Sydney Coal Railway | | | RSRV |
| 6 | SCR | SYDNEY COAL RAILWAY | | | SCAC4 |
| 7 | SCRD | SO COAST TRANS & DIST INC | | | SCAC4 |
| 8 | SCRE | SCHAFER EXPRESS AND TRANSFER CO | | | SCAC1 |
| 9 | SCRE | SCHAFER EXPRESS AND TRANSFER CO | | | SCAC4 |
| 10 | SCRF | South Carolina Central R.R. Co., Inc. | added 4/1988; 1/1994-7/2005 | | NAKINA |
| 11 | SCRF | South Carolina Central R.R. Co., Inc. | added 4/88; 1/94-7/2000 | | NRHS |
| 12 | SCRF | SOUTH CAROLINA CENTRAL RAILROAD CO., INC. | | | PWRC |
| 13 | SCRF | South Carolina Central Railroad | | | RSRV |
| 14 | SCRF | SOUTH CAROLINA CENTRAL RAILROAD CO | | | SCAC4 |
| 15 | SCRG | STREET CARTAGE LIMITED | | | SCAC4 |
| 16 | SCRL | SCRAP METAL SERVICES LLC | | | SCAC4 |
| 17 | SCRM | SEACOR MARINE LLC | | | SCAC4 |
| 18 | SCRN | SUN COAST RESOURCES INC | | | SCAC4 |
| 19 | SCRO | SAUCIER, PIERRE TRANSPORT INC | | | SCAC4 |
| 20 | SCRP | S C TRANSPORT | | | SCAC4 |
| 21 | SCRQ | SCORE | | | SCAC4 |
| 22 | SCRT | SACRAMENTO COUNTY REGIONAL TRANSIT DISTRICT | | | PWRC |
| 23 | SCRTD | Southern California Regional Transit District | | USA | TRAFFIC |
| 24 | SCRU | SEACROSS SHIPPING LLP | | IND | BIC |
| 25 | SCRU | STAR CONTAINER SERVICES | | | SCAC4 |
| 26 | SCRW | SEAWAY COMMERCIAL RAILWAY | | | PWRC |
| 27 | SCRW | Seaway Commercial Railway | | | RSRV |
| 28 | SCRW | SCHERME | | | SCAC4 |
| 29 | SCRX | Susquehanna Chemical Corp. | 4/1947; 1/1950 (not listed) | | NAKINA |
| 30 | SCRX | Santa Clarita Railway d/b/a James Clark & Co. | 7/2000 (not listed) | | NAKINA |
| 31 | SCRX | South Carolina Public Railways | 7/2005 | | NAKINA |
| 32 | SCRX | Santa Clarita Railway d/b/a James Clark & Co. | Jul-00 | | NRHS |
| 33 | SCRX | *SUSQUEHANNA CHEMICAL CORP. | | | PWRC |
| 34 | SCRX | *SANTA CLARITA RAILWAY, DBA JAMES CLARK & COMPANY | | | PWRC |
| 35 | SCRX | *SCHUYLKILL COUNTY RAIL AUTHORITY | | | PWRC |
| 36 | SCRX | +SOUTH CAROLINA PUBLIC RAILWAYS | | | PWRC |
| 37 | SCRX | Santa Clarita Railway (James Clark and) | | | RSRV |
| 38 | SCRX | SOUTH CAROLINA PUBLIC RAILWAYS | | | SCAC4 |
| 39 | SCRY | SOUTH CENTRAL RECYCLING | | | SCAC4 |
| 40 | SCRZ | SQUAW CREEK COAL COMPANY | | | PWRC |
| 41 | SCRZ | Squaw Creek Coal Company | | USA | TRAFFIC |
