| 1 | AM | Aeromexico Aerovias de Mexico S.A. de C.V. | ICAO: AMX, Callsign: Aeromexico, IATA Prefix: 139, | MEX | AVCODES |
| 2 | AM | Aeronaves de Mexico, S.A. | | MEX | AVCODES |
| 3 | AM | Aerovias de Mexico S.A. de C.V. | ICAO: AMX, Callsign: Aeromexico, IATA Prefix: 139, Name changed from Aeromexico Aerovias de Mexico S.A. de C.V. | MEX | AVCODES |
| 4 | AM | Arkansas & Missouri R.R. Co. | added 10/1986; 1/1994-7/2005 | | NAKINA |
| 5 | AM | Arkansas & Missouri R.R. Co. | added 10/86; 1/94-7/2000 | | NRHS |
| 6 | AM | ARKANSAS & MISSOURI RAILROAD COMPANY | | | PWRC |
| 7 | AM | Arkansas and Missouri Railroad | | | RSRV |
| 8 | AM | Arkansas and Missouri Railroad | | USA | TRAFFIC |
| 9 | AM | Andreas Mühlbauer Bau GmbH | | DE | VKM |
| 10 | AMA | JSC Aircompany ATMA | IATA: IM, Callsign: Adik, IATA Prefix: 707, Name changed to Jupiter Jet Airlines LLP. Founded on 26 September 1996. | KZ | AVCODES |
| 11 | AMA | Jupiter Jet Airlines LLP | IATA: IM, Callsign: Adik, IATA Prefix: 707, Name changed from JSC Aircompany ATMA. Founded on 26 September 1996. | KZ | AVCODES |
| 12 | AMA | Aircompany Moalem Aviation | Callsign: Moalem, | KS | AVCODES |
| 13 | AMA | ATMA | | | ICAO1 |
| 14 | AMAB | AMA TRANSPORT INC | | | SCAC3 |
| 15 | AMAC | A & M AGRICULTURAL CO-OP INC | | | SCAC3 |
| 16 | AMAC | AUTOTRANSPORTES MAC | | | SCAC4 |
| 17 | AMADOR | Amador Stage Lines (CA) | | US-CA | TRAFFIC |
| 18 | AMAE | ALLIED MARITIME INC | | | SCAC4 |
| 19 | AMAGI | Amagi Railway (Amatetsu) | | J | TRAFFIC |
| 20 | AMAI | AMARAL TRUCK CO | | | SCAC3 |
| 21 | AMAI | A M A PLASTICS LTD | | | SCAC4 |
| 22 | AMAJ | A M AIR COURIERS INC | | | SCAC3 |
| 23 | ÅmÅJ | Åmål - Årjäng Järnväg | 1927 - 1937 | S | svenska-lok.se |
| 24 | AMAK | AMTOTE INTERNATIONAL INC | | | SCAC4 |
| 25 | AMAL | ACT MARITIME CO LTD | | | SCAC3 |
| 26 | AMAL | A M A N LOGISTICS LTD | | | SCAC4 |
| 27 | AMAL | Air Malta | Real: AMC | M | TRAFFIC |
| 28 | AMAM | AMERICAN ALUMINUM RECYCLE | | | SCAC3 |
| 29 | AMAM | ALMI MARINE MANAGEMENT SA | | | SCAC4 |
| 30 | AMAN | AMERICAN MATERIALS TRANSPORT INC | | | SCAC4 |
| 31 | AMAO | AMERICAN MOVING & STORAGE CO INC | | | SCAC3 |
| 32 | AMAP | A M A TRANSPORTATION CO INC | | | SCAC3 |
| 33 | AMAP | A M A TRANSPORTATION CO INC | | | SCAC4 |
| 34 | AMAQ | AMERICAN AEROSOL TRUCKING | | | SCAC3 |
| 35 | AMAQ | AMERICAN-IRAQI SHIPPING LINE INC | | | SCAC4 |
| 36 | AMAR | ANRECE & MORGA AUTO EXPRESS SA DE C | | | SCAC4 |
| 37 | AMAS | ARROW MOVING AND STORAGE CO, INC | | | SCAC3 |
| 38 | AMAS | ARROW MOVING AND STORAGE CO, INC | | | SCAC4 |
| 39 | AMAU | ALIANÇA EQUIQ. CONTÊINERES MANAUS LTDA | | BR | BIC |
| 40 | AMAU | ANTILLES MARINE SERVICES CO., LTD | | | SCAC3 |
| 41 | AMAU | AMA-ASSOCIATED MARITIME AGENCIES LT | | | SCAC4 |
| 42 | AMAU | Air Mauritius | Real: MAU | MUS | TRAFFIC |
| 43 | AMAW | APEX SHIPPING CO | | | SCAC4 |
| 44 | AMAX | AMAX Coal Co. | added 7/1988; 1/1994; eliminated 7/1997; 7/2000-7/2005 (not listed) | | NAKINA |
| 45 | AMAX | AMAX Coal Co., a Division of AMAX, Inc. | added 10/1974; 1/1975-1/1985; eliminated 7/1988 | | NAKINA |
| 46 | AMAX | Arthur M. Adler Tank Line (General American Tank Car Corp.) | 8/1920-7/1923 | | NAKINA |
| 47 | AMAX | AMAX Coal Co., a Division of AMAX, Inc. | added 10/74; 1/75-1/80; eliminated 7/88 | | NRHS |
| 48 | AMAX | AMAX Coal Co. | added 7/88; 1/94; eliminated 7/97; 7/2000 | | NRHS |
| 49 | AMAX | *ARTHUR M. ADLER TANK LINE (GENERAL AMERICAN TANK CAR CORP.) | | | PWRC |
| 50 | AMAX | +AMAX COAL COMPANY | | | PWRC |
| 51 | AMAX | AMAX Coal | | | RSRV |
| 52 | AMAX | AMAX COAL COMPANY | | | SCAC4 |
| 53 | AMAY | AMERICAN DIVERSIFIED DISTRIBUTION L | | | SCAC4 |
| 54 | AMB | Deutsche Rettungsflugwacht | IATA: 1I, Callsign: Civil Air Ambulance, Name changed to DRF - Stiftung Luftrettung Gemeinnuetzige AG. Previously used IATA code DV | D | AVCODES |
| 55 | AMB | Deutsche Rettungsflugwacht | IATA: DV, Callsign: Air Ambulance, Designator DV recalled by IATA | D | AVCODES |
| 56 | AMB | Deutsche Rettungsflugwacht | IATA: 1I | | ICAO1 |
| 57 | AMB | AMERICAN BRIDGE | | | PWRC |
| 58 | AMBA | AMBASSADOR MARITIME INC | | | SCAC4 |
| 59 | AMBB | AMERITRANS CORPORATION | | | SCAC3 |
| 60 | AMBC | AMBUCAR SERVICE | | | SCAC3 |
| 61 | AMBC | AMSTELLAND SHIPPING B V | | | SCAC4 |
| 62 | AMBER | Anber Coaches | City: Rayleigh | GB | TRAFFIC |
| 63 | AMBF | AMERICAN BASIC TRANSPORT INC | | | SCAC3 |
| 64 | AMBF | ARMSTRONG RELOCATION CO (BROKERAGE | | | SCAC4 |
| 65 | AMBG | AMERICAN BARGE CARRIERS INC | | | SCAC3 |
| 66 | AMBI | AMAN BROS INC | | | SCAC3 |
| 67 | AMBJ | A-M BUS CO INC | | | SCAC3 |
| 68 | AMBJ | ARMENTA BOJORQUEZ, JESUS | | | SCAC4 |
| 69 | AMBL | ALIMENTOS BOLONIA | | | SCAC4 |
| 70 | AMBM | AMERICAN BONDED MOVING & STORAGE CO | | | SCAC3 |
| 71 | AMBN | AMSBERRY INC | | | SCAC3 |
| 72 | AMBN | AMSBERRY INC | | | SCAC4 |
| 73 | AMBO | AMBROSE TRUCKING | | | SCAC3 |
| 74 | AMBP | AMERICAS BEST INC | | | SCAC3 |
| 75 | AMBP | AMEY, B TRANSPORT | | | SCAC4 |
| 76 | AMBQ | AMERICAN BACKHAULERS CORPORATION | | | SCAC3 |
| 77 | AMBR | AMBROSIA, C D, TRUCKING CO | | | SCAC3 |
| 78 | AMBR | Ambrogio Trasporti S.p.A. | | IT | VKM |
| 79 | AMBRO | AMBRO S.A | | RO | VKM |
| 80 | AMBS | AMBROSE TRUCKING INC | | | SCAC3 |
| 81 | AMBT | AMBER TRUCK LINES | | | SCAC3 |
| 82 | AMBT | AMBERT INTERNATIONAL LOGISTICS | | | SCAC4 |
| 83 | AMBU | AMBER LINE, INC. | | | PWRC |
| 84 | AMBU | Amber Line | | | RSRV |
| 85 | AMBU | AMBER LINE, INC. | | | SCAC3 |
| 86 | AMBU | AMBER LINE, INC. | | | SCAC4 |
| 87 | AMBV | AMI BUS SERVICE | | | SCAC3 |
| 88 | AMBW | AMBASSADOR BROKERAGE LTD | | | SCAC3 |
| 89 | AMBW | AMERICAS BESTWAY | | | SCAC4 |
| 90 | AMBX | American Boiler Works, Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 91 | AMBX | Amherst Industries, Inc. | added 1/1961; 4/1961-1/1985; eliminated 10/1990 | | NAKINA |
| 92 | AMBX | Amherst Barge Co. | added 1/1960; eliminated 1/1961 | | NAKINA |
| 93 | AMBX | American Bridge Co. | 8/1920-7/1936; 7/1937 (not listed) | | NAKINA |
| 94 | AMBX | Amherst Barge Co. | added 1/60 | | NRHS |
| 95 | AMBX | Amherst Industries, Inc. | 4/61-1/80; eliminated 10/90 | | NRHS |
| 96 | AMBX | American Boiler Works, Inc. | Jul-00 | | NRHS |
| 97 | AMBX | *AMERICAN BRIDGE CO. | | | PWRC |
| 98 | AMBX | +AMERICAN BOILER WORKS INC. [AMHERST BARGE; AMHERST INDUSTRIES] | | | PWRC |
| 99 | AMBX | Amherst Industries (American Boiler Works) | | | RSRV |
| 100 | AMBY | AMBOY EXPRESS | | | SCAC3 |