| 1 | WPC | Commandair C.A. | Callsign: Command Air, | YV | AVCODES |
| 2 | WPCA | WORLD PETROLEUM CORPORATION | | | SCAC4 |
| 3 | WPCB | WESTRON PUMPS COMPRESSORS & BLOWERS | | | SCAC4 |
| 4 | WPCL | WESTERN PETROLEUM CO INC | | | SCAC4 |
| 5 | WPCN | WORLDWIDE PROCUREMENT COMPANY INC | | | SCAC4 |
| 6 | WPCO | WITHUS TRANSPORTATION CORPORATION | | | SCAC4 |
| 7 | WPCT | WRIGHT, PC TRUCKING LLC | | | SCAC4 |
| 8 | WPCW | WENATCHEE PETROLEUM CO | | | SCAC4 |
| 9 | WPCX | Transportation Management, Inc. | 1/1975; added 4/1975; eliminated 7/1976 | | NAKINA |
| 10 | WPCX | Missouri Valley Walnut Co. | added 7/1976; 1/1980; eliminated 1/1982 | | NAKINA |
| 11 | WPCX | Transportation Management, Inc. | 1/75; added 4/75 | | NRHS |
| 12 | WPCX | Missouri Valley Walnut Co. | 1/80; eliminated 1/82 | | NRHS |
| 13 | WPCX | MISSOURI VALLEY WALNUT CO. (TRANSPORTATION MANAGEMENT, INC.) | | | PWRC |
| 14 | WPCY | WILLOW PUBLISHING COMPANY | | | SCAC4 |
