| 1 | SDX | Servicio Tecnico Aero de Mexico, S.A. de C.V. | Callsign: Servicio Tecnico, | MEX | AVCODES |
| 2 | SDX | Servicio Tecnico Aero De Mexico | | | ICAO1 |
| 3 | SDX | Squire Dingee Co. | 7/1930-4/1961; eliminated 10/1963 | | NAKINA |
| 4 | SDX | Squire Dingee Co. | 4/38-4/61 | | NRHS |
| 5 | SDX | SQUIRE DINGEE CO. | | | PWRC |
| 6 | SDXA | SEABIRD EXPLORATION | | | SCAC4 |
| 7 | SDXC | SKY DISTRIBUTION EXPRESS INC | | | SCAC4 |
| 8 | SDXD | SUMMERSID | | | SCAC4 |
| 9 | SDXE | SAME DAY XPRESS LLC | | | SCAC4 |
| 10 | SDXF | SUDDENLY EXPRESS CORP | | | SCAC4 |
| 11 | SDXG | SANDY-X GROUP | | | SCAC4 |
| 12 | SDXH | SUPERLOAD TRANSPORT LLC | | | SCAC4 |
| 13 | SDXI | SHADDAI TRANSPORT INC, THE | | | SCAC4 |
| 14 | SDXJ | SHEPHERD TRANSPORT INC | | | SCAC4 |
| 15 | SDXK | SPEED DOX INC | | | SCAC4 |
| 16 | SDXL | STRYD TRANSPORTATION LLC | | | SCAC4 |
| 17 | SDXM | SNYDER TRANSPORTATION INC | | | SCAC4 |
| 18 | SDXN | SEED-EX INC | | | SCAC4 |
| 19 | SDXO | SALADA TRANSPORTATION | | | SCAC4 |
| 20 | SDXP | SDX | | | SCAC4 |
| 21 | SDXV | SIDLE TRANSIT SERVICE INC | | | SCAC4 |
