| 1 | ASA | Alaska Airlines, Inc. | IATA: AS, Callsign: Alaska, IATA Prefix: 027, | USA | AVCODES |
| 2 | ASA | Alaska Airlines, Inc. | IATA: AS | | ICAO1 |
| 3 | ASA | THE BAY LINE RAILROAD [ATLANTA & ST. ANDREWS BAY RY] | | | PWRC |
| 4 | ASAB | The Bay Line R.R., L.L.C. | added 4/1994; 7/2000-7/2005 | | NAKINA |
| 5 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | 7/1954-1/1994; eliminated 4/1994 | | NAKINA |
| 6 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | 10/57-1/94; eliminated 4/94 | | NRHS |
| 7 | ASAB | The Bay Line R.R., L.L.C. | added 4/94; 7/2000 | | NRHS |
| 8 | ASAB | THE BAY LINE RAILROAD [ATLANTA & ST. ANDREWS BAY RY] | | | PWRC |
| 9 | ASAB | Atlanta and St. Andrews Bay Railway (Bay Line Railroad) | | | RSRV |
| 10 | ASAB | ATLANTA & SAINT ANDREWS BAY RAILWAY | | | SCAC3 |
| 11 | ASAB | Atlanta & Saint Andrews Bay Ry. Co. | | USA | TRAFFIC |
| 12 | ASAC | ALL-STATES TRANSPORT CORP | | | SCAC3 |
| 13 | ASAC | ASTAR AIR CARGO INC (SUB-CONTRACTIN | | | SCAC4 |
| 14 | ASAD | AMBASSADOR SERVICES INC | | | SCAC4 |
| 15 | ASAF | ASSOCIATED AIR FREIGHT INC | | | SCAC3 |
| 16 | ASAF | ASSOCIATED AIR FREIGHT INC | | | SCAC4 |
| 17 | ASAG | ARCTIC SLOPE/ALASKA GENERAL | | | SCAC3 |
| 18 | ASAH | ALL STATES ASPHALT INC | | | SCAC3 |
| 19 | ASAH | ALL STATES ASPHALT INC | | | SCAC4 |
| 20 | ASAHI | Asahikawa Denkikidou (Asahikawa Electric Railway) | Previously operated a few suburban tramway lines | J | TRAFFIC |
| 21 | ASAJ | ASAP FREIGHT SYSTEMS | | | SCAC4 |
| 22 | ASAL | ASAP LINES INC | | | SCAC3 |
| 23 | ASAM | ALL STATES MOVING AND STORAGE CO | | | SCAC3 |
| 24 | ASAN | ACF SHIPPING AND TRADING INC | | | SCAC4 |
| 25 | ASAN | Autosan | | PL | TRAFFIC |
| 26 | ASAO | ASAP EXPRESS TRANSPORT INC | | | SCAC3 |
| 27 | ASAO | A-SAP AUTO TRANSPORT LLC | | | SCAC4 |
| 28 | ASAP | ASAP EXPRESS INC | | | SCAC3 |
| 29 | ASAP | ASAP TRUCKING COMPANY | | | SCAC4 |
| 30 | ASAQ | ALLSTATES AIR CARGO INC | | | SCAC3 |
| 31 | ASAQ | ALLSTATES AIR CARGO INC | | | SCAC4 |
| 32 | ASAS | ASSOCIATED SHIPPERS SERVICE | | | SCAC3 |
| 33 | ASAS | ASAP DELIVERY | | | SCAC4 |
| 34 | ASAT | A S & R TRUCKING CO | | | SCAC3 |
| 35 | ASAU | ASASLINE | | B | BIC |
| 36 | ASAU | ARGON S A | | | SCAC3 |
| 37 | ASAU | PRAXAIR ESPANA | | | SCAC4 |
| 38 | ASAW | ASAP TOWING & STORAGE CO INC | | | SCAC4 |
| 39 | ASAX | Arkansas Steel Associates, LLC | added 10/2008 | | NAKINA |
| 40 | ASAX | ARKANSAS STEEL ASSOCIATES | | | SCAC4 |
| 41 | ASAY | A.S.A.P. DELIVERY | | | SCAC3 |
| 42 | ASAY | A S A P DELIVERY | | | SCAC4 |
| 43 | ASAZ | ASARCO | | | PWRC |
