| 1 | PSX | Pacific Southwest Airlines, Inc. | Callsign: Smiley, | USA | AVCODES |
| 2 | PSX | Pacific Southwest Airlines | IATA: PS | | ICAO1 |
| 3 | PSX | Pierce & Stevens Chemical Corp. | added 4/1956; eliminated 7/1956 | | NAKINA |
| 4 | PSX | Pierce & Stevens, Inc. | 7/1937-7/1954; eliminated 4/1956 | | NAKINA |
| 5 | PSX | Pierce & Stevens, Inc. | 4/38-1/52 | | NRHS |
| 6 | PSX | Pierce & Stevens Chemical Corp. | eliminated 7/56 | | NRHS |
| 7 | PSX | PIERCE & STEVENS CHEMICAL CORP. | | | PWRC |
| 8 | PSXD | POSA TRANSPORT LTD | | | SCAC4 |
| 9 | PSXE | PS TRANSPORTES | | | SCAC4 |
| 10 | PSXG | PERRAS EXCAVATING INC | | | SCAC4 |
| 11 | PSXH | PAC SUN TRANSPORT INC | | | SCAC4 |
| 12 | PSXI | PS EXPRESS INC | | | SCAC3 |
| 13 | PSXJ | PTS TRANSPORT LTD | | | SCAC4 |
| 14 | PSXL | PETROLEUM SOUTH TRANSPORTATION LLC | | | SCAC4 |
| 15 | PSXP | PARCEL SHIPPERS EXPRESS INC | | | SCAC3 |
| 16 | PSXQ | P S X | | | SCAC3 |
| 17 | PSXR | PENAS TRANSPORT | | | SCAC4 |
| 18 | PSXS | PORT SERVICE EXPRESS | | | SCAC4 |
| 19 | PSXT | PSS TRANSPORTATION LLC | | | SCAC4 |
| 20 | PSXU | PSG CONTAINER CO LTD | | HK | BIC |
