| 12501 | ARMN | Arriva Midland North | | GB | TRAFFIC |
| 12502 | ARMO | ARMOLD TRANSFER & STORAGE COMPANY I | | | SCAC3 |
| 12503 | ARMO | ARMENTA SOTO, BERNARDINO | | | SCAC4 |
| 12504 | ARMP | ARMSTRONG, MERVYN E | | | SCAC3 |
| 12505 | ARMQ | ARMORED MOTORS SERVICE | | | SCAC3 |
| 12506 | ARMQ | ARCHITECTURAL METALCRAFT INDUSTRIES | | | SCAC4 |
| 12507 | ARMR | ARMORED MOTOR SERVICE CORPORATION | | | SCAC3 |
| 12508 | ARMR | ARMBRUSTER MOVING & STORAGE INC | | | SCAC4 |
| 12509 | ARMR | Atlas Rhein main GmbH | | DE | VKM |
| 12510 | ARMS | ARMSTRONG RELOCATION | | | SCAC4 |
| 12511 | ARMT | ARMSTRONG TRANSFER AND STORAGE COMP | | | SCAC3 |
| 12512 | ARMT | ARMSTRONG RELOCATION CO | | | SCAC4 |
| 12513 | ARMU | ADAPTAINER LTD | | GB | BIC |
| 12514 | ARMU | A.R.M.E.C. LTD | | | SCAC3 |
| 12515 | ARMU | ADAPTAINER B V | | | SCAC4 |
| 12516 | ARMV | AIR-RIDE MOVING & STORAGE INC | | | SCAC3 |
| 12517 | ARMW | ARMASOL LINE | | | SCAC3 |
| 12518 | ARMW | ARIADMAR LIMITED | | | SCAC4 |
| 12519 | ARMX | American Rail & Marine Corp. | added 4/1984; eliminated 4/1987; 1/1994-7/2005 (not listed) | | NAKINA |
| 12520 | ARMX | Armco Steel Corp. | 1/1952 (not listed); 7/1954-10/1957; eliminated 1/1959 | | NAKINA |
| 12521 | ARMX | Armco Steel Corp. | 1/52-10/57; eliminated 1/59 | | NRHS |
| 12522 | ARMX | American Rail & Marine Corp. | added 4/84; eliminated 4/87; 1/94-7/2000 | | NRHS |
| 12523 | ARMX | *ARMCO STEEL CORP. (ELIMINATED 1/1959) | | | PWRC |
| 12524 | ARMX | +AMERICAN RAIL & MARINE CORPORATION | | | PWRC |
| 12525 | ARMX | American Rail and Marine Corporation | | | RSRV |
| 12526 | ARMX | AMERICAN RAIL & MARINE CORPORATION | | | SCAC4 |
| 12527 | ARMZ | ARMASAL LINE - AMERICAN RAIL & MARINE CORP. (ARMCO INDUSTRIES) | | | PWRC |
| 12528 | ARMZ | Armasal Line | | | RSRV |
| 12529 | ARMZ | ARMASAL LINE | | | SCAC4 |
| 12530 | ARN | Air Canada Regional, Inc. | IATA: QK, Callsign: Transcan, IATA Prefix: 983, Name changed to Air Canada Jazz. ICAO Designator changed to JZZ. Name changed from Air Nova Inc. ICAO callsign changed from Nova. | CDN | AVCODES |
| 12531 | ARN | Air Nova, Inc. | IATA: QK, Callsign: Nova, IATA Prefix: 983, Merged into Air Canada Regional Inc. during 2001. Air Canada Connector | CDN | AVCODES |
| 12532 | ARN | Aviaservice | | AM | AVCODES |
| 12533 | ARN | Astra Airlines SA | Callsign: Swisslease, | CH | AVCODES |
| 12534 | ARN | Air Nova, Inc. | Callsign: Air Nova, ICAO callsign changed to Nova | CDN | AVCODES |
| 12535 | ARN | Aeronexus Corporate Pty Ltd | IATA: RN, Callsign: Aeronex, IATA Prefix: 557, | ZA | AVCODES |
| 12536 | ARN | Alberta RailNet, Inc. | 7/2000-7/2005 | | NAKINA |
| 12537 | ARN | Canadian National Railways | added 7/2007 | | NAKINA |
| 12538 | ARN | Albert RailNet, Inc. | Jul-00 | | NRHS |
| 12539 | ARN | *ALBERT RAILNET, INC. | | | PWRC |
| 12540 | ARN | CANADIAN NATIONAL RAILWAYS | | | PWRC |
| 12541 | ARN | Alberta RailNet (Canadian National Railway) | | | RSRV |
| 12542 | ARN | ALBERTA RAILNET INC | | | SCAC4 |
| 12543 | ARN | Alberta RailNet | | CDN | TRAFFIC |
| 12544 | ARNA | ARNOLD, A & SON TRANSFER & STORAGE | | | SCAC3 |
| 12545 | ARNA | A ARNOLD WORLD CLASS RELOCATION | | | SCAC4 |
| 12546 | ARNB | ARNOLD BROS TRANSPORT LTD | | | SCAC3 |
| 12547 | ARNB | ARNOLD BROS TRANSPORT LTD | | | SCAC4 |
| 12548 | ARNB | Arnold Brothers Transport Ltd. | | USA | TRAFFIC |
| 12549 | ARNC | ARNEL COMPANY, THE | | | SCAC3 |
| 12550 | ARNC | AMERICAN CALAN INC | | | SCAC4 |
| 12551 | ARND | ARNOLD, AL, TRUCKING COMPANY | | | SCAC3 |
| 12552 | ARND | ARENS INC | | | SCAC4 |
| 12553 | ARNE | Arriva London North-East | | GB | TRAFFIC |
| 12554 | ARNF | ARNOFF MOVING & STORAGE INC | | | SCAC3 |
| 12555 | ARNF | ARNOFF MOVING & STORAGE INC | | | SCAC4 |
| 12556 | ARNH | ARMENTA SEED COMPANY INC | | | SCAC4 |
| 12557 | ARNI | ARGONNE NATIONAL LABORATORY | | | SCAC3 |
| 12558 | ARNJ | ARNESON, JERRY INC | | | SCAC3 |
| 12559 | ARNK | ARNOLD TRANSPORTATION | | | SCAC3 |
| 12560 | ARNK | ARNETT TRUCKING CO | | | SCAC4 |
| 12561 | ARNL | ARETHOUSA NAVIGATION CO. NICOSIA CY | | | SCAC3 |
| 12562 | ARNM | AMADO ROJAS, NIVIA LUZMILA | | | SCAC4 |
| 12563 | ARNN | ARANI NAVIGATION COMPANY | | | SCAC3 |
| 12564 | ARNO | ARNOLD BROTHERS TRUCKING INC | | | SCAC3 |
| 12565 | ARNO | Air Nova | Real: arn | CDN | TRAFFIC |
| 12566 | ARNP | ARNIE ENTERPRISES INC | | | SCAC3 |
| 12567 | ARNP | AMERICAN TRANSPORT | | | SCAC4 |
| 12568 | ARNQ | ARNOLD TRANSFER & STORAGE INC | | | SCAC3 |
| 12569 | ARNR | ARNESON, MARK TRUCKING | | | SCAC4 |
| 12570 | ARNT | AMERICAN TRANSPORTATION | | | SCAC3 |
| 12571 | ARNT | AMERICAN TRANSPORTATION | | | SCAC4 |
| 12572 | ARNU | ARAN INTERNATIONAL SDN BHD | | | SCAC4 |
| 12573 | ARNV | ARNESON TRUCKING | | | SCAC3 |
| 12574 | ARNV | ARNOLD OIL INC | | | SCAC4 |
| 12575 | ARO | Arrow Aviation Ltd. | Callsign: Arrow, | CDN | AVCODES |
| 12576 | ARO | Arrow Aviation Ltd. | | | ICAO1 |
| 12577 | ARO | ARROW TRAILWAYS OF TEXAS | | | SCAC4 |
| 12578 | AROB | AEROBUS | | | SCAC3 |
| 12579 | AROB | ASTRO TRANSPORT | | | SCAC4 |
| 12580 | AROC | ARGENOS MARINE COMPANY LTD | | | SCAC3 |
| 12581 | AROD | ARONDELLI TRUCKING SERVICE | | | SCAC3 |
| 12582 | AROD | ADIRONDACK ROWING | | | SCAC4 |
| 12583 | AROF | AMERICAN ROLL-ON ROLL-OFF CARRIER L | | | SCAC4 |
| 12584 | AROF | Aberdeen and Rockfish R.R. Co. | Real: AR | USA | TRAFFIC |
| 12585 | AROI | ARMOUR OIL CO | | | SCAC3 |
| 12586 | AROI | ARROW LOGISTICS INC | | | SCAC4 |
| 12587 | AROJ | A R O TRUCKING | | | SCAC3 |
| 12588 | AROK | ARROW TRUCKING CO | | | SCAC3 |
| 12589 | AROL | AERO LIQUID TRANSIT INC | | | SCAC3 |
| 12590 | AROM | ARROW MARINE TRANSPORT | | | SCAC3 |
| 12591 | AROM | AUTOTRANSPORTES ROMEDU S A DE C V | | | SCAC4 |
| 12592 | ARON | ARROW TRUCKING CO | | | SCAC3 |
| 12593 | AROO | ARNOLD, MAX & SONS TRANSPORTATION L | | | SCAC4 |
| 12594 | AROQ | ARROW MOVING INC | | | SCAC3 |
| 12595 | AROR | AGROREFRIGERADOS SAN JOSE SA DE CV | | | SCAC4 |
| 12596 | AROT | ARROW TRANSPORTATION COMPANY | | | SCAC3 |
| 12597 | AROU | ARO CONTLEASE LTD | | | SCAC3 |
| 12598 | AROV | ARROW VAN & STORAGE, LTD | | | SCAC3 |
| 12599 | AROV | A R T TRANSPORTATION SERVICES INC | | | SCAC4 |
| 12600 | AROW | ARROW MAILING | | | SCAC4 |
