| 1 | WTM | Waitemata Aero Club (Inc) | | NZ | AVCODES |
| 2 | WTM | Verein Wiener Tramwaymuseum | | A | TRAFFIC |
| 3 | WTMA | WEST MESA TRUCKING INC | | | SCAC4 |
| 4 | WTMC | WESLEYS & TINA EXPRESS INC | | | SCAC4 |
| 5 | WTMF | WTM DESIGN LTD | | | SCAC4 |
| 6 | WTMK | WESTERN MARKETING INC | | | SCAC4 |
| 7 | WTMN | WATTMAN TRAINS & TRAMS INC | | | SCAC4 |
| 8 | WTMO | WEIL/THOMAN MOVING & STORAGE CO | | | SCAC1 |
| 9 | WTMO | WEIL/THOMAN MOVING & STORAGE CO | | | SCAC4 |
| 10 | WTMX | WISCONSIN TROLLEY MUSEUM INC. | | | PWRC |