| 1 | RTL | Rheintalflug Seewald Gesellschaft mbH | IATA: WE, Callsign: Rheintal, IATA Prefix: 915, Name changed to Rheintalflug Vorarlberger Luftfahrtgi | A | AVCODES |
| 2 | RTL | Rheintalflug Vorarlberger Luftfahrtgi | IATA: WE, Callsign: Rheintal, IATA Prefix: 915, Ceased operations on 31 December 2002. Desginator WE* reinstated by IATA. Name changed from Rheintalflug Seewald Gesellschaft mbH | A | AVCODES |
| 3 | RTL | Air Thanlwin Holding Company Limited | IATA: ST, Callsign: Royal Bird, Name changed from Yangon Airways Limited in February 2014. IATA Designator changed from YH*. ICAO designator changed from AYG. IATA designator changed from HK* w.e.f. 15 June 2009. | MYA | AVCODES |
| 4 | RTL | Riviera Trains Ltd. | | UK | VKM |
| 5 | RTLA | RANTALA TRUCKING | | | SCAC3 |
| 6 | RTLC | RIGHT TRUCKING LINES LTD INC | | | SCAC3 |
| 7 | RTLD | RTL SERVICES INC | | | SCAC4 |
| 8 | RTLE | RANGER TRUCK LINE INC | | | SCAC3 |
| 9 | RTLE | ROSE TRANSPORT LLC | | | SCAC4 |
| 10 | RTLH | RTL HOLDINGS INC | | | SCAC3 |
| 11 | RTLH | REAL TALK LLC | | | SCAC4 |
| 12 | RTLI | REIN TRUCK LINE INC | | | SCAC3 |
| 13 | RTLK | RITCHIE LAKELAND TRANSPORT INC | | | SCAC4 |
| 14 | RTLM | RANGE TRANSPORT LTD | | | SCAC3 |
| 15 | RTLM | ROUND THE LAKES MOTOR EXPRESS INC | | | SCAC4 |
| 16 | RTLN | RUSSELL TRUCKING LINE, INC | | | SCAC3 |
| 17 | RTLO | R TRUCK LINE | | | SCAC3 |
| 18 | RTLO | ROSA TRANSPORTATION LLC | | | SCAC4 |
| 19 | RTLOG | Rail Time Logistics GmbH | | DE | VKM |
| 20 | RTLP | RAMOS TANK | | | SCAC4 |
| 21 | RTLQ | RTL RELIABLE TRANSPORTATION LINK | | | SCAC4 |
| 22 | RTLR | R T S I | | | SCAC3 |
| 23 | RTLR | RAPID TRUCK LINES INC | | | SCAC4 |
| 24 | RTLT | R T L TRANSPORT | | | SCAC3 |
| 25 | RTLU | RTS LOGISTIC CO., LTD | | RUS | BIC |
| 26 | RTLW | RELIABLE TANK LINE LIMITED PARTNERS | | | SCAC3 |
| 27 | RTLW | RELIABLE TANK LINE LIMITED PARTNERS | | | SCAC4 |
| 28 | RTLX | Relco Tank Line, Inc. | 7/2000-7/2005 | | NAKINA |
| 29 | RTLX | Relco Leasing Corp. | 1/1994 | | NAKINA |
| 30 | RTLX | Relco Tank Line, Inc. | added 10/1986 | | NAKINA |
| 31 | RTLX | Relco Tank Line Division of Relco Nevada Corp. | added 10/1976; 1/1980; eliminated 10/1986 | | NAKINA |
| 32 | RTLX | Relco Tank Line, Inc. | added 1/1972; 1/1975; eliminated 10/1976 | | NAKINA |
| 33 | RTLX | Relco Tank Line | added 7/1971; eliminated 1/1972 | | NAKINA |
| 34 | RTLX | Relco Leasing Corp. | added 4/1970; 4/1970; eliminated 7/1971 | | NAKINA |
| 35 | RTLX | Relco Tank Line, Inc. | added 10/1964; 7/1965-10/1966; eliminated 4/1970 | | NAKINA |
| 36 | RTLX | Roby Tank Line | 7/1923-7/1935 | | NAKINA |
| 37 | RTLX | American Maize Products Co. | 7/1937-4/1938 | | NAKINA |
| 38 | RTLX | Roby Tank Line (American Maize Products Co.) | Apr-38 | | NRHS |
| 39 | RTLX | Relco Tank Line, Inc. | 7/65-10/66; eliminated 4/70 | | NRHS |
| 40 | RTLX | Relco Leasing Corp. | added 4/70; 4/70 | | NRHS |
| 41 | RTLX | Relco Tank Line, Inc. | added 1/72; 1/75 | | NRHS |
| 42 | RTLX | Relco Tank Line Division of Relco Nevada Corp. | 1/80; eliminated 10/86 | | NRHS |
| 43 | RTLX | Relco Tank Line, Inc. | added 10/86 | | NRHS |
| 44 | RTLX | Relco Leasing Corp. | Jan-94 | | NRHS |
| 45 | RTLX | Relco Tank Line, Inc. | Jul-00 | | NRHS |
| 46 | RTLX | *ROBY TANK LINE | | | PWRC |
| 47 | RTLX | *AMERICAN MAIZE PRODUCTS CO. | | | PWRC |
| 48 | RTLX | +RELCO NEVADA CORP., RELCO TANK LINE DIV. | | | PWRC |
| 49 | RTLX | Relco Nevada Corporation (Relco Tank Line Division) | | | RSRV |
| 50 | RTLX | RELCO TANK LINE | | | SCAC3 |
| 51 | RTLX | RELCO TANK LINE INC | | | SCAC4 |
| 52 | RTLY | RTL INC | | | SCAC3 |
| 53 | RTLY | RICE TRANSPORT LLC | | | SCAC4 |
