| 5001 | RJRX | R. J. ROESLING & CO. (SHIPPERS CAR LINE, DIV. of ACF INDUSTRIES) | | | PWRC |
| 5002 | RJRX | R.J. Roesling & Co. (ACF Industries) | | | RSRV |
| 5003 | RJS | Aeroservicios Jet, S.A. de C.V. | Callsign: Aserjet, | MEX | AVCODES |
| 5004 | RJS | Aeroservicios Jet | | | ICAO1 |
| 5005 | RJSC | RJ'S TRUCKING | | | SCAC4 |
| 5006 | RJSD | RLJ'S DELIVERY SERVICE CO INC | | | SCAC3 |
| 5007 | RJSE | RESTO TRUCKING | | | SCAC3 |
| 5008 | RJSG | R J S LOGISTICS INC | | | SCAC4 |
| 5009 | RJSK | RJS TRUCKS | | | SCAC4 |
| 5010 | RJSK | Railjet Slowakia | | SK | TRAFFIC |
| 5011 | RJSK | RegioJet a.s. | | SK | VKM |
| 5012 | RJSL | R & J SOLUTIONS INC | | | SCAC4 |
| 5013 | RJSN | ROBINSON, JASON A | | | SCAC3 |
| 5014 | RJSP | RJS TRANSPORT INC | | | SCAC4 |
| 5015 | RJSQ | R J S TRANSPORT INC | | | SCAC4 |
| 5016 | RJSR | RJS TRANSPORT LLC | | | SCAC4 |
| 5017 | RJSS | RUIZ, JOSE S | | | SCAC4 |
| 5018 | RJSW | R & J SAVAGE TRANSPORTATION LLC | | | SCAC4 |
| 5019 | RJT | RA Jet Aeroservicios, S.A. de C.V. | Callsign: RA Jet, | MEX | AVCODES |
| 5020 | RJT | RA Jet Aeroservicios | | | ICAO1 |
| 5021 | RJT | R & J TRANSPORTATION INC | | | SCAC4 |
| 5022 | RJTA | R & J TRUCKING | | | SCAC3 |
| 5023 | RJTA | R & J TRUCKING | | | SCAC4 |
| 5024 | RJTB | R J EXPRESS INC | | | SCAC3 |
| 5025 | RJTC | R & J TRANSPORTATION CO INC | | | SCAC3 |
| 5026 | RJTE | R & J TRUCKING & EXCAVATING | | | SCAC3 |
| 5027 | RJTG | R & J TRUCKING COMPANY | | | SCAC3 |
| 5028 | RJTH | ROSS, J T HAULING INC | | | SCAC3 |
| 5029 | RJTH | R J TRANSFER | | | SCAC4 |
| 5030 | RJTI | R-JO TRUCKING CORP | | | SCAC3 |
| 5031 | RJTJ | R J TRUCKING SERVICE | | | SCAC3 |
| 5032 | RJTK | R J TRUCKING INC | | | SCAC3 |
| 5033 | RJTK | RUD, JOE TRUCKING INC | | | SCAC4 |
| 5034 | RJTL | R J TRANSPORT INC | | | SCAC3 |
| 5035 | RJTM | R J TRUCKING LLC | | | SCAC4 |
| 5036 | RJTN | R J TRUCKING | | | SCAC3 |
| 5037 | RJTO | R & J TRUCKING | | | SCAC3 |
| 5038 | RJTP | RJ TRANSPORTATION INC | | | SCAC3 |
| 5039 | RJTQ | R & J TRUCKING | | | SCAC3 |
| 5040 | RJTQ | RAJA TRUCKING LLC | | | SCAC4 |
| 5041 | RJTR | R & J TRUCKING | | | SCAC3 |
| 5042 | RJTS | R J TRANSIT CO INC | | | SCAC3 |
| 5043 | RJTT | R & J EXPRESS LLC | | | SCAC4 |
| 5044 | RJTV | R J TRUCKING INC | | | SCAC3 |
| 5045 | RJTW | RJT TRUCKING INC | | | SCAC3 |
| 5046 | RJUR | R & J TRUCKING & RECYCLING INC | | | SCAC4 |
| 5047 | RJVR | RJV TRANSPORT INC | | | SCAC4 |
| 5048 | RJVS | RUIZ, J V & SON TRUCKING | | | SCAC3 |
| 5049 | RJVT | RJV TRANSFER | | | SCAC4 |
| 5050 | RJWE | R J W ENTERPRISES INC | | | SCAC3 |
| 5051 | RJWE | R J W LOGISTICS INC | | | SCAC4 |
| 5052 | RJWI | RJW TRANSPORT INC | | | SCAC4 |
| 5053 | RJWM | R J W MOVING INC | | | SCAC3 |
| 5054 | RJWM | R J W MOVING INC | | | SCAC4 |
| 5055 | RJWN | REINING, W J & SONS | | | SCAC3 |
| 5056 | RJWT | RATCLIFF, J W TRUCKING | | | SCAC3 |
| 5057 | RJWT | RJW TRUCKING CO INC | | | SCAC4 |
| 5058 | RJWV | R J TRUCKING | | | SCAC3 |
| 5059 | RJXC | ROADRAJ TRANSPORT INC | | | SCAC4 |
| 5060 | RJXM | RJ TRANSFER SYSTEMS | | | SCAC4 |
| 5061 | RJXP | R J EXPRESS INC | | | SCAC3 |
| 5062 | RJXS | R J EXPRESS LTD | | | SCAC4 |
| 5063 | RJXT | ROJO TRANSPORT | | | SCAC4 |
| 5064 | RJXU | RJ CO.,LTD | | J | BIC |
| 5065 | RJZ | Royal Jordanian Air Force | Callsign: Jordan Air Force, | JOR | AVCODES |
| 5066 | RJZ | Royal Jordanian Air Force | | | ICAO1 |
| 5067 | RK | Air Afrique | ICAO: RKA, Callsign: Airafric, IATA Prefix: 092, Declared bankrupt on 07 February 2002. | CI | AVCODES |
| 5068 | RK | Royal Khmer Airlines | ICAO: RKH, Callsign: Khmer Air, Designator RK reinstated by IATA. Designator FE recalled by IATA | K | AVCODES |
| 5069 | RK | Region-Airline | Founded in 2005. Commenced operations in 2006, Ceased operations in 2011. | RUS | AVCODES |
| 5070 | RK | Skyview Airways Co., Ltd. d/b/a Skyview | ICAO: RCT, Callsign: Green Sky, Founded in 2012. | T | AVCODES |
| 5071 | RK | Ryanair UK Limited | ICAO: RUK, Callsign: Blue Max, | GB | AVCODES |
| 5072 | RK | Rhenus Keolis GmbH & Co. KG | Mainz | D | privat-bahn.de |
| 5073 | RK | Rendsburger Kreisbahn | | D | TRAFFIC |
| 5074 | RK | Rhenus Keolis GmbH | | DE | VKM |
| 5075 | RKA | Air Afrique | IATA: RK, Callsign: Airafric, IATA Prefix: 092, Declared bankrupt on 07 February 2002. | CI | AVCODES |
| 5076 | RKA | Polar Airlines, State Unitary Enterprise Air Company | Callsign: Air Sakha, Name changed to Polar Airlines OJSC | RUS | AVCODES |
| 5077 | RKA | Polar Airlines OJSC | IATA: PI, Callsign: Air Sakha, Name changed from Polar Airlines, , State Unitary Enterprise Air Company. Purchased by JSC Airline Yakutia (R3/SYL) | RUS | AVCODES |
| 5078 | RKA | Air Afrique | | | ICAO1 |
| 5079 | RKAB | RENKAS, CRAIG W | | | SCAC4 |
| 5080 | RKAL | RECKART LOGISTICS INC. | | | SCAC4 |
| 5081 | RKAM | R & KA | | | SCAC4 |
| 5082 | RKAP | RED KAP SALES INC | | | SCAC4 |
| 5083 | RKB | Rødkærsbro - Kjellerup Banen (Kjellerupbanen) | 1912 - 1924 | DK | jernbanen.dk |
| 5084 | RKB | Rødkærsbro - Kjellerup Banen (Kjellerupbanen) | 1912 - 1924 | DK | TRAFFIC |
| 5085 | RKBF | ROCKY BEACH FARMS INC | | | SCAC3 |
| 5086 | RKBL | ROYAL KENT BUS LINES INC | | | SCAC3 |
| 5087 | RKBL | RAKEBY LIMITED | | | SCAC4 |
| 5088 | RKBQ | RIVERA, K & B LIQUID LOGISTICS LLC | | | SCAC4 |
| 5089 | RKBS | RICKS BACKHOE SERVICE INC | | | SCAC4 |
| 5090 | RKC | Das Airlines | Callsign: Das Congo, | ZRE | AVCODES |
| 5091 | RKC | DAS Airlines | | | ICAO1 |
| 5092 | RKCC | ROCKET CITY CHARTER SERVICE INC | | | SCAC3 |
| 5093 | RKCE | ROCK CREEK EXPRESS INC | | | SCAC3 |
| 5094 | RKCG | RUKY INTERNATIONAL COMPANY | | | SCAC4 |
| 5095 | RKCL | RIMROCK COLONY | | | SCAC4 |
| 5096 | RKCT | ROCK CREEK TRUCKING | | | SCAC4 |
| 5097 | RKCW | RAKOWSKI CARTAGE & WRECKING LTD | | | SCAC4 |
| 5098 | RKCX | Knox Kershaw, Inc. | added 1/1984; eliminated 4/1985; 1/1994-7/2005 (not listed) | | NAKINA |
| 5099 | RKCX | Royce Kershaw Co., Inc. | eliminated 1/1984 | | NAKINA |
| 5100 | RKCX | Knox Kershaw Co., Inc. | added 1/1969; 4/1970-1/1980 | | NAKINA |
