| 1 | SPD | Airspeed Aviation, Inc. | IATA: 5S, Callsign: Speedline, Ceased operations | CDN | AVCODES |
| 2 | SPD | Sky Prime Aviation Services | IATA: UY, Callsign: Sky Prime, IATA designator UY recalled. | SA | AVCODES |
| 3 | SPD | Sky Prime Aviation Services | Callsign: Sky Prime, IATA designator UY recalled. | SA | AVCODES |
| 4 | SPD | Airspeed Aviation | | | ICAO1 |
| 5 | SPDA | SEATTLE CEDAR SUPPLY | | | SCAC4 |
| 6 | SPDB | SERVICE OIL ENTERPRISES CO | | | SCAC4 |
| 7 | SPDD | SPIDLE & SPIDLE INC | | | SCAC4 |
| 8 | SPDEM | Southern Pacific de México | | MEX | TRAFFIC |
| 9 | SPDF | SPECIALTY DISTRIBUTING CORP | | | SCAC4 |
| 10 | SPDG | SPADER FREIGHT SERVICES INC | | | SCAC4 |
| 11 | SPDJ | SABLE REFRIGERATED GROUP | | | SCAC4 |
| 12 | SPDO | SPELL, DONNIE TRUCKING | | | SCAC4 |
| 13 | SPDP | SPECIAL DISPATCH INC | | | SCAC4 |
| 14 | SPDR | SPADY TRANSPORT LTD | | | SCAC4 |
| 15 | SPDT | SPEEDX TRANSPORT | | | SCAC4 |
| 16 | SPDU | SPEDYCJA POLSKA SPEDCONT SPOLKA ZO.O. | | PL | BIC |
| 17 | SPDU | UNION PACIFIC [SOUTHERN PACIFIC TRANSP CO] | | | PWRC |
| 18 | SPDU | Southern Pacific Transportation (Spedycja Polska Spedcont) | | | RSRV |
| 19 | SPDU | SPEDYCJA POLSKA SPEDCONT SPOLKA ZO | | | SCAC4 |
| 20 | SPDW | SPEEDWA | | | SCAC4 |
| 21 | SPDX | Sterling Products Co. | 7/1935-4/1938 | | NAKINA |
| 22 | SPDX | Sterling Products Co. | Apr-38 | | NRHS |
| 23 | SPDX | STERLING PRODUCTS CO. | | | PWRC |
| 24 | SPDZ | UNION PACIFIC [SOUTHERN PACIFIC TRANSP CO] | | | PWRC |
| 25 | SPDZ | Southern Pacific Railroad (Union Pacific Railroad) | | | RSRV |
| 26 | SPDZ | UNION PACIFIC RAILROAD | | | SCAC4 |
