| 1 | AS | Alaska Airlines, Inc. | ICAO: ASA, Callsign: Alaska, IATA Prefix: 027, | USA | AVCODES |
| 2 | AS | Abilene & Southern Ry. Co. | 10/1957-1/1975 | | NAKINA |
| 3 | AS | Abilene & Southern Ry. Co. | 10/57-1/75 | | NRHS |
| 4 | AS | MISSOURI PACIFIC [ABILENE & SOUTHERN RWY.] (ELIMINATED 1/1979) | | | PWRC |
| 5 | AS | Abilene and Southern Railway (Missouri Pacific Railroad) | | | RSRV |
| 6 | AS | Alexander Schröter | | DE | VKM |
| 7 | ASA | Alaska Airlines, Inc. | IATA: AS, Callsign: Alaska, IATA Prefix: 027, | USA | AVCODES |
| 8 | ASA | Alaska Airlines, Inc. | IATA: AS | | ICAO1 |
| 9 | ASA | THE BAY LINE RAILROAD [ATLANTA & ST. ANDREWS BAY RY] | | | PWRC |
| 10 | ASAB | The Bay Line R.R., L.L.C. | added 4/1994; 7/2000-7/2005 | | NAKINA |
| 11 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | 7/1954-1/1994; eliminated 4/1994 | | NAKINA |
| 12 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | 10/57-1/94; eliminated 4/94 | | NRHS |
| 13 | ASAB | The Bay Line R.R., L.L.C. | added 4/94; 7/2000 | | NRHS |
| 14 | ASAB | THE BAY LINE RAILROAD [ATLANTA & ST. ANDREWS BAY RY] | | | PWRC |
| 15 | ASAB | Atlanta and St. Andrews Bay Railway (Bay Line Railroad) | | | RSRV |
| 16 | ASAB | ATLANTA & SAINT ANDREWS BAY RAILWAY | | | SCAC3 |
| 17 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | | USA | TRAFFIC |
| 18 | ASAC | ALL-STATES TRANSPORT CORP | | | SCAC3 |
| 19 | ASAC | ASTAR AIR CARGO INC (SUB-CONTRACTIN | | | SCAC4 |
| 20 | ASAD | AMBASSADOR SERVICES INC | | | SCAC4 |
| 21 | ASAF | ASSOCIATED AIR FREIGHT INC | | | SCAC3 |
| 22 | ASAF | ASSOCIATED AIR FREIGHT INC | | | SCAC4 |
| 23 | ASAG | ARCTIC SLOPE/ALASKA GENERAL | | | SCAC3 |
| 24 | ASAH | ALL STATES ASPHALT INC | | | SCAC3 |
| 25 | ASAH | ALL STATES ASPHALT INC | | | SCAC4 |
| 26 | ASAHI | Asahikawa Denkikidou (Asahikawa Electric Railway) | Previously operated a few suburban tramway lines | J | TRAFFIC |
| 27 | ASAJ | ASAP FREIGHT SYSTEMS | | | SCAC4 |
| 28 | ASAL | ASAP LINES INC | | | SCAC3 |
| 29 | ASAM | ALL STATES MOVING AND STORAGE CO | | | SCAC3 |
| 30 | ASAM | Asahi Motor Co. | Asahi Motor is a bus company within the Tobu Group | J | TRAFFIC |
| 31 | ASAN | ACF SHIPPING AND TRADING INC | | | SCAC4 |
| 32 | ASAN | Autosan | | PL | TRAFFIC |
| 33 | ASAO | ASAP EXPRESS TRANSPORT INC | | | SCAC3 |
| 34 | ASAO | A-SAP AUTO TRANSPORT LLC | | | SCAC4 |
| 35 | ASAP | ASAP EXPRESS INC | | | SCAC3 |
| 36 | ASAP | ASAP TRUCKING COMPANY | | | SCAC4 |
| 37 | ASAQ | ALLSTATES AIR CARGO INC | | | SCAC3 |
| 38 | ASAQ | ALLSTATES AIR CARGO INC | | | SCAC4 |
| 39 | ASAS | ASSOCIATED SHIPPERS SERVICE | | | SCAC3 |
| 40 | ASAS | ASAP DELIVERY | | | SCAC4 |
| 41 | ASAT | A S & R TRUCKING CO | | | SCAC3 |
| 42 | ASAU | ASASLINE | | B | BIC |
| 43 | ASAU | ARGON S A | | | SCAC3 |
| 44 | ASAU | PRAXAIR ESPANA | | | SCAC4 |
| 45 | ASAW | ASAP TOWING & STORAGE CO INC | | | SCAC4 |
| 46 | ASAX | Arkansas Steel Associates, LLC | added 10/2008 | | NAKINA |
| 47 | ASAX | ARKANSAS STEEL ASSOCIATES | | | SCAC4 |
| 48 | ASAY | A.S.A.P. DELIVERY | | | SCAC3 |
| 49 | ASAY | A S A P DELIVERY | | | SCAC4 |
| 50 | ASAZ | ASARCO | | | PWRC |
| 51 | ASB | Air-Spray 1967 Ltd. | Callsign: Air Spray, | CDN | AVCODES |
| 52 | ASB | Air-Spray 1967 Ltd. | | | ICAO1 |
| 53 | ASB | Arbeiter-Samariter-Bund | | D | TRAFFIC |
| 54 | ASBC | ALPHA SCHOOL BUS COMPANY INC | | | SCAC3 |
| 55 | ASBC | ASSOCIATED HARDWOODS TRUCKING LLC | | | SCAC4 |
| 56 | ASBD | ARMSTRONG TRANSFER & STORAGE CO INC | | | SCAC4 |
| 57 | ASBE | ASBESTOS EXPRESS LIMITED | | | SCAC3 |
| 58 | ASBF | ASBESTOS EASTERN TRANSPORT (US) INC | | | SCAC3 |
| 59 | ASBH | A & S TRANSPORTATION INC | | | SCAC4 |
| 60 | ASBI | ASSET BASED INTERMODAL | | | SCAC4 |
| 61 | ASBL | ASCOT BUS LINES INC | | | SCAC3 |
| 62 | ASBM | ASBURY, M L, INC | | | SCAC3 |
| 63 | ASBO | ASHEBORO FORD TRACTOR INC | | | SCAC3 |
| 64 | ASBP | A S P FORWARDING | | | SCAC3 |
| 65 | ASBQ | ASSOCIATED BULK CARRIERS LTD | | | SCAC3 |
| 66 | ASBQ | AVALON LOGISTICS LLC | | | SCAC4 |
| 67 | ASBR | ARTESANIAS BRIONES | | | SCAC4 |
| 68 | ASBS | A D STABLES | | | SCAC4 |
| 69 | ASBT | ASBURY TRANSPORTATION CO INC | | | SCAC4 |
| 70 | ASBU | ANTWERP SHIPPING & CHARTERING SVCS | | | SCAC3 |
| 71 | ASBURY | Asbury Park - New York Transit | | USA | TRAFFIC |
| 72 | ASBW | ACCURATE SHIPPING RESOURCES | | | SCAC4 |
| 73 | ASBX | American Ship Building Co. | 8/1920-7/1930 | | NAKINA |
| 74 | ASBX | American Synthetic Rubber Corp. | added 4/1961; 4/1961-4/1970; eliminated 7/1974 | | NAKINA |
| 75 | ASBX | American Synthetic Rubber Corp. | added 4/61; 4/61-4/70; eliminated 7/74 | | NRHS |
| 76 | ASBX | *AMERICAN SHIP BUILDING CO. | | | PWRC |
| 77 | ASBX | *AMERICAN SYNTHETIC RUBBER CORP. | | | PWRC |
| 78 | ASBX | AMERICAN SYNTHETIC RUBBER CORP | | | SCAC3 |
| 79 | ASBY | ASHBY TRUCKING CORP | | | SCAC4 |
| 80 | ASBZ | ASB BRIDGE | | | PWRC |
| 81 | ASC | Air Star Corporation | IATA: KK, Callsign: Air Star, | CDN | AVCODES |
| 82 | ASC | Alas del Sur | | BOL | AVCODES |
| 83 | ASC | Air Star Corporation | | | ICAO1 |
| 84 | ASC | ASICAR SRL | | RO | VKM |
| 85 | ASCA | ASCA MARINE INC. | | | SCAC3 |
| 86 | ASCA | AAA SPECIALIZED INC | | | SCAC4 |
| 87 | ASCB | ALLSCO BUILDING PRODUCTS INC | | | SCAC4 |
| 88 | ASCC | A S A P COURIER CORPORATION | | | SCAC3 |
| 89 | ASCC | ALCHEMIST SPECIALTY CARRIERS INC | | | SCAC4 |
| 90 | ASCD | ASSOCIATED TRUCKING INC | | | SCAC3 |
| 91 | ASCD | ARGUS CARRIERS LTD | | | SCAC4 |
| 92 | ASCE | ARTESANO COPPER IMPORTS | | | SCAC4 |
| 93 | ASCEN | Ascendos Rail Leasing | | EU | TRAFFIC |
| 94 | ASCEN | Ascendos Rail Leasing Sarl | | LU | VKM |
| 95 | ASCF | ALLSTATE CONSOLIDATORS AND FORWARDE | | | SCAC3 |
| 96 | ASCH | ASCHENBRENNER, DONALD H | | | SCAC3 |
| 97 | ASCH | A S C LINES | | | SCAC4 |
| 98 | ASCHR | Schröder Reisen - Andreas Schröder e.K. | | D | TRAFFIC |
| 99 | ASCI | ASSOCIATED COURIERS INC | | | SCAC3 |
| 100 | ASCI | ASSOCIATED COURIERS INC | | | SCAC4 |
