| 1 | REG | Regourd Aviation | Callsign: Regourd, | F | AVCODES |
| 2 | REG | Regional Air Services Limited | IATA: 8N, Callsign: Regional Services, | EAT | AVCODES |
| 3 | REG | Regional Air Services | | | ICAO1 |
| 4 | REG | Regional Railways | Regional Railways was one of the three passenger sectors of British Rail created in the 1980s that existed until privatisation in the 1990s. The sector was originally called Provincial, and ran regional non-express services. | GB | TRAFFIC |
| 5 | REGA | REDIEHS, GEORGE A, COMPANY, INC | | | SCAC3 |
| 6 | REGA | REGINA TRANSPORT INC | | | SCAC4 |
| 7 | REGAL | Regal Busways | | GB | TRAFFIC |
| 8 | REGB | RAZOR ENTERPRISE INC | | | SCAC4 |
| 9 | REGBH | regiobus Hannover GmbH | Real: regiobus | D | TRAFFIC |
| 10 | REGC | REGNUM CORP | | | SCAC4 |
| 11 | REGCJ | REGIONAL SRL | | RO | VKM |
| 12 | REGE | R E G LOGISTICS INC | | | SCAC4 |
| 13 | REGF | REGION FREIGHT LLINES INC | | | SCAC3 |
| 14 | REGG | REGIONAL STORAGE & TRANSPORT INC | | | SCAC3 |
| 15 | REGH | REDEKER, GUS H JR | | | SCAC3 |
| 16 | REGH | REGHOLD CORPORATION | | | SCAC4 |
| 17 | REGH | Reg | City: Hertford | GB | TRAFFIC |
| 18 | REGI | REGIONAL AIR CARGO | | | SCAC3 |
| 19 | REGIO | Regio-Bahn | | DE | VKM |
| 20 | REGJ | RAJA ENTERPRISES | | | SCAC4 |
| 21 | REGK | REGENCY TANKERS CORPORATION NEW YOR | | | SCAC3 |
| 22 | REGK | REGENCY TANKERS CORPORATION NEW YOR | | | SCAC4 |
| 23 | REGL | READING GRAIN AND LUMBER CO | | | SCAC3 |
| 24 | REGO | REEDER, HOWARD S INC | | | SCAC3 |
| 25 | REGO | REGIO TRANSPORTES MONTEMAYOR S A DE | | | SCAC4 |
| 26 | REGP | REGIONAL PETROLEUM CORP | | | SCAC3 |
| 27 | REGP | REGALORAMA URESTY SA DE CV | | | SCAC4 |
| 28 | REGQ | RIGIONAL TRUCKING INC | | | SCAC3 |
| 29 | REGR | RED EAGLE TRANSPORT | | | SCAC4 |
| 30 | REGR | RegioRail | | F | TRAFFIC |
| 31 | REGS | REGGIES SERVICES | | | SCAC3 |
| 32 | REGS | REGATTASPORT | | | SCAC4 |
| 33 | REGT | REGIONAL TRANSPORTATION COMPANY, INC. | | | SCAC3 |
| 34 | REGU | RCL FEEDER PTE LTD | | SGP | BIC |
| 35 | REGU | REGIONAL CONTAINER LINES PTE LTD | | | SCAC4 |
| 36 | REGX | Regus Industries | | | RSRV |
| 37 | REGX | SUNNY FARMS | | | SCAC4 |
| 38 | REGY | REISH, GARY L | | | SCAC3 |
| 39 | REGY | REGENCY DISTRIBUTION LTD | | | SCAC4 |
