| 12001 | ARBK | ARAB MARITIME PETROLEUM TRANSPORT | | | SCAC3 |
| 12002 | ARBK | ARROWHEAD TRANSPORTATION SERVICES I | | | SCAC4 |
| 12003 | ARBL | ARMBRO TRANSPORT LTD | | | SCAC3 |
| 12004 | ARBL | ARMBRO TRANSPORT INC | | | SCAC4 |
| 12005 | ARBN | ARTUROS TRANSFER | | | SCAC4 |
| 12006 | ARBO | ARBOR FREIGHT SERVICE INC | | | SCAC3 |
| 12007 | ARBP | ARBALLO TRANSPORTATION INC | | | SCAC3 |
| 12008 | ARBQ | ANDERSON, ROBERT ALDEN | | | SCAC3 |
| 12009 | ARBQ | ART LOGISTICS INC | | | SCAC4 |
| 12010 | ARBR | A R B INC | | | SCAC4 |
| 12011 | ARBR | Rail ARB s.r.o | | SK | VKM |
| 12012 | ARBS | ARMOR BUILDING SUPPLY | | | SCAC4 |
| 12013 | ARBT | ARBET ASSEMBLY AND DISTRIBUTING SER | | | SCAC3 |
| 12014 | ARBTP | Arriva Bus Transport Polska | | PL | TRAFFIC |
| 12015 | ARBW | A RELIABLE TRUCKING & WAREHOUSE CO | | | SCAC3 |
| 12016 | ARBW | ARBEC TOOL & MACHINE LTD | | | SCAC4 |
| 12017 | ARBX | Arnold Bros. Pickle & Preserve Co. | 7/1930 | | NAKINA |
| 12018 | ARBX | ARNOLD BROTHERS PICKLE & PRESERVE CO. | | | PWRC |
| 12019 | ARC | Air Routing International Corp. | IATA: ZJ, Name changed to Air Routing International LP | USA | AVCODES |
| 12020 | ARC | Air Routing International Corp. | IATA: XC, | USA | AVCODES |
| 12021 | ARC | Air Routing International L.P. | IATA: ZJ, Name changed from Air Routing International Corp. | USA | AVCODES |
| 12022 | ARC | Air Routing International Corp. | | | ICAO1 |
| 12023 | ARC | Alexander R.R. Co. | 1/1975-7/2005 | | NAKINA |
| 12024 | ARC | Alexander R.R. Co. | 1/75-7/2000 | | NRHS |
| 12025 | ARC | ALEXANDER RAILROAD CO. | | | PWRC |
| 12026 | ARC | Alexander Railroad | | | RSRV |
| 12027 | ARC | Amey Roadstone Corporation | | GB | TRAFFIC |
| 12028 | ARC | Aqaba Railway Corporation | | JO | VKM |
| 12029 | ARCA | ACE RELOCATION SYSTEMS INC | | | SCAC4 |
| 12030 | ARCB | AROMATIC TRUCKING CORP | | | SCAC3 |
| 12031 | ARCC | ARNCO TRANSPORTATION INC | | | SCAC4 |
| 12032 | ARCD | ARCADIA VAN LINES | | | SCAC3 |
| 12033 | ARCE | ARAB CARTAGE & EXPRESS CO INC | | | SCAC4 |
| 12034 | ARCE | ARCELOR | | | TRAFFIC |
| 12035 | ARCESE | Arcese | | I | TRAFFIC |
| 12036 | ARCF | AMERICAN CARTAGE | | | SCAC3 |
| 12037 | ARCF | AIR CARTAGE EXPRESS LLC | | | SCAC4 |
| 12038 | ARCG | AIR CARGO TRANSIT INC | | | SCAC3 |
| 12039 | ARCG | AIR CARGO TRANSIT INC | | | SCAC4 |
| 12040 | ARCH | ARCHER, GARY TRUCKING | | | SCAC3 |
| 12041 | ARCH | ARPIN OF RICHMOND INC | | | SCAC4 |
| 12042 | ARCHI | Archirodon | | GR | TRAFFIC |
| 12043 | ARCI | AMERICAN RAILWAY CAR INSTITUTE | | | PWRC |
| 12044 | ARCI | ARC TRUCKING MESSENGER CORP | | | SCAC3 |
| 12045 | ARCI | AEROCARGO INC | | | SCAC4 |
| 12046 | ARCJ | ARCHER, JUNE E | | | SCAC3 |
| 12047 | ARCK | A R CARRIERS INC | | | SCAC3 |
| 12048 | ARCK | ARMSTRONG RELOCATION CO KNOXVILLE T | | | SCAC4 |
| 12049 | ARCM | ARCTIC EXPRESS INC | | | SCAC3 |
| 12050 | ARCM | ARTHUR COMPANIES INC | | | SCAC4 |
| 12051 | ARCM | Arcelor Mittal | | EU | TRAFFIC |
| 12052 | ARCN | ARCH TRANSPORTATION | | | SCAC3 |
| 12053 | ARCO | ARCO PIPE LINE COMPANY | | | SCAC3 |
| 12054 | ARCO | ARMSTRONG RELOCATION COMPANY OHIO L | | | SCAC4 |
| 12055 | ARCO | ARCO Transportation GmbH | | D | TRAFFIC |
| 12056 | ARCO | Arco Transportation GmbH | | DE | VKM |
| 12057 | ARCP | ARCADE SHIPPING A S | | | SCAC3 |
| 12058 | ARCQ | AMERICAS CATCH INC | | | SCAC4 |
| 12059 | ARCR | AIR CONSOLIDATORS INC | | | SCAC3 |
| 12060 | ARCR | A R C TRANSPORTATION INC | | | SCAC4 |
| 12061 | ARCS | AMERISOUTH RECYCLING AND CONSULTING | | | SCAC4 |
| 12062 | ARCU | SUNMARINE SHIPPING SERVICES LLC | | UAE | BIC |
| 12063 | ARCU | AREUCON LEASING LTD | | | SCAC3 |
| 12064 | ARCU | SUNMARINE SHIPPING SERVICES | | | SCAC4 |
| 12065 | ARCV | ARC TRANSPORTATION | | | SCAC4 |
| 12066 | ARCW | ARCTIC WHITNEY | | | SCAC3 |
| 12067 | ARCX | Arizona Rail Car Inc. | 1/1994-7/2005 (not listed) | | NAKINA |
| 12068 | ARCX | Alaska Rail Car Co. | added 7/1964; 7/1965-1/1980; eliminated 7/1992 | | NAKINA |
| 12069 | ARCX | Arizona Rail Car Inc. | 1/94-7/2000 | | NRHS |
| 12070 | ARCX | Alaska Rail Car Co. | added 7/64; 7/65-1/80; eliminated 7/92 | | NRHS |
| 12071 | ARCX | *ALASKA RAILCAR CO. | | | PWRC |
| 12072 | ARCX | *AMERICAN RAILWAY COMPANY OF TEXAS | | | PWRC |
| 12073 | ARCX | +(RPSX) ARIZONA RAIL CAR, INC | | | PWRC |
| 12074 | ARCX | Alaska Rail Car (Arizona Rail Car) | | | RSRV |
| 12075 | ARCX | ALASKA RAIL CAR CO | | | SCAC3 |
| 12076 | ARCX | ARIZONA RAIL CAR INC | | | SCAC4 |
| 12077 | ARCY | ALLTRANS CARRIERS INC | | | SCAC4 |
| 12078 | ARCZ | Arriva vlaky s.r.o. | Real: ARR | CZ | TRAFFIC |
| 12079 | ARD | ATA Aerocondor Transportes Aéreos Lda. | IATA: 2B, Callsign: Aerocondor, IATA Prefix: 088, Suspended operation in May 2008. Designator 2B reinstated by IATA | P | AVCODES |
| 12080 | ARD | Aerocondor Transportes Aereos Lda. | IATA: 8W, IATA designator changed from 2B | P | AVCODES |
| 12081 | ARD | Aerocondor | IATA: 2B | | ICAO1 |
| 12082 | ARD | Aerocondor | | PE | TRAFFIC |
| 12083 | ARDA | ARD, AUBURN D | | | SCAC3 |
| 12084 | ARDB | ARD B TRANSPORT INC | | | SCAC4 |
| 12085 | ARDC | ADIRONDACK RAILWAY | | | PWRC |
| 12086 | ARDC | ARMISTEAD TRUCKING INC | | | SCAC3 |
| 12087 | ARDD | AMERICAN INTERMODAL TRANSPORT INC | | | SCAC4 |
| 12088 | ARDE | A-RIDE | | | SCAC3 |
| 12089 | ARDE | ARDELLA TRUCKING INC | | | SCAC4 |
| 12090 | ARDE | Arriva Deutschland | | D | TRAFFIC |
| 12091 | ARDG | ARDS TRUCKING COMPANY INCORPORATED | | | SCAC3 |
| 12092 | ARDG | ARDS TRUCKING COMPANY INCORPORATED | | | SCAC4 |
| 12093 | ARDH | ARDEN AIR FREIGHT INC | | | SCAC3 |
| 12094 | ARDH | ARTECH REDUCTION TECHNOLOGIES | | | SCAC4 |
| 12095 | ARDI | A & R DELIVERY SERVICE | | | SCAC3 |
| 12096 | ARDJ | ARD TRUCKING | | | SCAC3 |
| 12097 | ARDJ | AUTO TRANSPORTES SAHORA DE B C | | | SCAC4 |
| 12098 | ARDK | ALLARDS | | | SCAC3 |
| 12099 | ARDK | ARVOR INC | | | SCAC4 |
| 12100 | ARDL | AMERICAN ROAD LINES INC | | | SCAC3 |
