| 1 | ATK | AeroTACA | | | ICAO1 |
| 2 | ATK | AMTRAK (NATIONAL RAILROAD PASSENGER CORP.) | | | PWRC |
| 3 | ATKA | ALMI TANKERS S A | | | SCAC4 |
| 4 | ATKC | AMTRAK (NATIONAL RAILROAD PASSENGER CORP.) | | | PWRC |
| 5 | ATKC | A TRUCKING COMPANY | | | SCAC3 |
| 6 | ATKC | ASPRO TANKER CORPORATION | | | SCAC4 |
| 7 | ATKD | AMERICAN TRUCKING CO | | | SCAC3 |
| 8 | ATKE | A TRUCK EXPRESS INC | | | SCAC4 |
| 9 | ATKF | ARSENAL TRUCKING LLC | | | SCAC4 |
| 10 | ATKH | AMERICAN TRUCK LINES INC | | | SCAC3 |
| 11 | ATKI | ASPEN TANKER, INC. | | | SCAC3 |
| 12 | ATKI | AMRIT TRUCKING INC | | | SCAC4 |
| 13 | ATKJ | ATKINS TRUCKING | | | SCAC3 |
| 14 | ATKJ | A TRUCK CONNECTION | | | SCAC4 |
| 15 | ATKK | ABC TRUCKING OF TEXAS | | | SCAC3 |
| 16 | ATKL | AMERICAN TRUCKLOAD TRANSPORT INC | | | SCAC3 |
| 17 | ATKP | AITKEN TRUCKING | | | SCAC3 |
| 18 | ATKP | AMERICAN TRUCK PARTS INC | | | SCAC4 |
| 19 | ATKQ | ATKINSON TRUCKING, INC | | | SCAC3 |
| 20 | ATKQ | A-TRAIN TRUCKING INC | | | SCAC4 |
| 21 | ATKR | AKERS TRUCK LINE | | | SCAC3 |
| 22 | ATKS | ALICE TANKSHIPS CORPORATION | | | SCAC3 |
| 23 | ATKS | ASSOCIATED TRUCKING SERVICES INC | | | SCAC4 |
| 24 | ATKU | ACTIVE TANK SDN. BHD. | | MAL | BIC |
| 25 | ATKV | ANIA TANKER CORPORATION | | | SCAC3 |
| 26 | ATKX | Allegheny Tank Car Co. | 8/1920-7/1923 | | NAKINA |
| 27 | ATKX | ALLEGHENY TANK CAR CO. | | | PWRC |
