| 1 | SSA | Sisav | Callsign: Sisav, | I | AVCODES |
| 2 | SSAA | SALT SPRING AIR | | | SCAC4 |
| 3 | SSAB | SSAB Tunnplåt AB | | SE | VKM |
| 4 | SSAC | SS TRUCKING | | | SCAC4 |
| 5 | SSAG | SSB TRUCKING LTD | | | SCAC4 |
| 6 | SSAK | SMYTH MOVING SERVICE OF ALASKA INC | | | SCAC4 |
| 7 | SSAL | SOTO SALAS, GERARDO | | | SCAC4 |
| 8 | SSAM | Sault Ste. Marie Bridge Co. | added 4/1993; 1/1994-7/2005 | | NAKINA |
| 9 | SSAM | Sault Ste. Marie Bridge Co. | added 4/93; 1/94-7/2000 | | NRHS |
| 10 | SSAM | SAULT STE. MARIE BRIDGE COMPANY (WISCONSIN CENTRAL SUBSIDIARY) | | | PWRC |
| 11 | SSAM | Sault Ste. Marie Bridge (Wisconsin Central) | | | RSRV |
| 12 | SSAM | SAULT STE MARIE BRIDGE | | | SCAC4 |
| 13 | SSAN | STUART, S ANTIQUES | | | SCAC4 |
| 14 | SSANG | Ssangyong Cement Industrial Co. | | ROK | TRAFFIC |
| 15 | SSAP | SOS TRANSPORTATION LLC | | | SCAC4 |
| 16 | SSAT | SOLANO GONZALEZ, SANTIAGO | | | SCAC4 |
| 17 | SSAV | SECURITY STORAGE AND VAN COMPANY | | | SCAC4 |
| 18 | SSAY | SOUTHERN STEAMSHIP AGENCY INC | | | SCAC4 |
