| 1 | SSX | Lynx Aviation, Inc. | IATA: L3, Callsign: Shasta, Subsidiary of Republic Airways Holdings, Inc. ICAO designator changed from SHA | USA | AVCODES |
| 2 | SSX | Belgium Exel | Callsign: Sunshine Exel, | B | AVCODES |
| 3 | SSX | Southern States Phosphate and Fertilizer Co. | added 1/1953; eliminated 1/1954 | | NAKINA |
| 4 | SSX | Southern States Phosphate and Fertilizer Co. | added 1/53 | | NRHS |
| 5 | SSX | SOUTHERN STATES PHOSPHATE & FERTILIZER CO. | | | PWRC |
| 6 | SSXB | STS TRANSPORTATION LLC | | | SCAC4 |
| 7 | SSXD | S & S EXPRESS LTD | | | SCAC4 |
| 8 | SSXK | SOUTH SIDE TRANSPORTATION INC | | | SCAC4 |
| 9 | SSXL | SOMAL STAR TRANSPORT INC | | | SCAC4 |
| 10 | SSXM | SOMERSET TRANSPORT LLC | | | SCAC4 |
| 11 | SSXN | SAM SUNG EXPRESS INC | | | SCAC4 |
| 12 | SSXQ | SHUTTLE SERVICE XPRESS | | | SCAC4 |
| 13 | SSXR | STRAIGHT SHOT EXPRESS | | | SCAC4 |
| 14 | SSXS | STRAIGHT SHOT EXPRESS | | | SCAC4 |
| 15 | SSXU | SAMSON SERVICE LLC | | RUS | BIC |
| 16 | SSXV | S & S TRANSPORTATION SERVICES | | | SCAC4 |
| 17 | SSXW | S & S EXPRESS | | | SCAC4 |
| 18 | SSXY | SUMMIT 66 OIL CO INC | | | SCAC4 |
