| 1 | REX | Ram Air Freight, Inc. | Callsign: Ram Express, | USA | AVCODES |
| 2 | REX | Regional Express Pty Limited | IATA: ZL, IATA Prefix: 899, | AUS | AVCODES |
| 3 | REX | Ram Air Freight | | | ICAO1 |
| 4 | REX | REA Express, Inc. | added 1/1971; eliminated 4/1974 | | NAKINA |
| 5 | REX | REA Express, owned and operated by Railway Express Agency, Inc. | eliminated 1/1971 | | NAKINA |
| 6 | REX | Railway Express Agency, Inc. | 7/1937-4/1938 (not listed); 1/1941-4/1970 | | NAKINA |
| 7 | REX | Railway Express Agency, Inc. | 1/52-4/70 | | NRHS |
| 8 | REX | REA Express, Inc. | eliminated 4/74 | | NRHS |
| 9 | REX | REX EXPRESS, INC. (RAILWAY EXPRESS AGENCY, INC.) | | | PWRC |
| 10 | REX | Rail Express Systems | | GB | TRAFFIC |
| 11 | REXA | REA EXPRESS INC | | | SCAC3 |
| 12 | REXA | Railway Express Agency, Inc. | Real: REX | USA | TRAFFIC |
| 13 | REXC | ROCKET EXPRESS DELIVERY INC | | | SCAC4 |
| 14 | REXD | RED EXPRESS | | | SCAC4 |
| 15 | REXE | R E X CARTAGE COMPANY | | | SCAC3 |
| 16 | REXF | ROLL-EX FREIGHTWAYS INC | | | SCAC4 |
| 17 | REXG | REX TRANSPORT | | | SCAC3 |
| 18 | REXI | REX MOVING & STORAGE CO | | | SCAC3 |
| 19 | REXJ | RJ'S EXPEDITING | | | SCAC4 |
| 20 | REXK | ROADTRAN EXPRESS | | | SCAC4 |
| 21 | REXL | ROBERVAL EXPRESS LIMITED | | | SCAC3 |
| 22 | REXL | RAIL EXPRESS LLC | | | SCAC4 |
| 23 | REXM | REX MOTOR TRANS, INC | | | SCAC3 |
| 24 | REXM | ROMAN EXPRESS INC | | | SCAC4 |
| 25 | REXN | REBEL EXPRESS INC | | | SCAC3 |
| 26 | REXN | REBEL EXPRESS INC | | | SCAC4 |
| 27 | REXO | REXCO | | | SCAC3 |
| 28 | REXO | ROUTE 88 TRANSPORTATION INC | | | SCAC4 |
| 29 | REXP | RUDOLF EXPRESS CO | | | SCAC3 |
| 30 | REXP | REDBIRD EXPRESS LLC | | | SCAC4 |
| 31 | REXQ | KING, REX | | | SCAC3 |
| 32 | REXQ | RIO EXPRESS | | | SCAC4 |
| 33 | REXS | R-EXPRESS INC | | | SCAC3 |
| 34 | REXS | RAMA EXPRESS | | | SCAC4 |
| 35 | REXSK | REXIAS, a.s. | | SK | VKM |
| 36 | REXT | REX TRANSPORTATION CO | | | SCAC3 |
| 37 | REXU | REXWAL SERVICES S A | | | SCAC4 |
| 38 | REXV | ROYAL EXPRESS TRANSPORT INC | | | SCAC3 |
| 39 | REXV | RUNWAY EXPRESS | | | SCAC4 |
| 40 | REXW | REX WAREHOUSE & DISTRIBUTING | | | SCAC3 |
| 41 | REXW | REXWAL SERVICES SA | | FR | VKM |
| 42 | REXWL | REXWAL SERVICES SA | | CH | VKM |
| 43 | REXX | IRESIN LLC | | | PWRC |
| 44 | REXX | IRESIN LLC | | | SCAC4 |
| 45 | REXY | REIDS EXPRESS INC | | | SCAC3 |
