| 5501 | RLHL | ROLLING HILLS TRUCKING | | | SCAC3 |
| 5502 | RLHQ | RAIL HIGHWAY SERVICES INC | | | SCAC3 |
| 5503 | RLHS | R & L HYDRAULIC SERVICE | | | SCAC3 |
| 5504 | RLHT | RAIL HEAD TRANSFER INC | | | SCAC3 |
| 5505 | RLHY | RED LINE HEAVY HAUL | | | SCAC4 |
| 5506 | RLI | R Lines, S.A. | Callsign: Anjou, | F | AVCODES |
| 5507 | RLI | Reliant Air Charter, Inc. | IATA: L0, Callsign: Reliant, Designator L0 recalled by IATA. | USA | AVCODES |
| 5508 | RLI | Reliant Air Charter, Inc. | Callsign: Reliant, Designator L0 recalled by IATA. | USA | AVCODES |
| 5509 | RLIB | RELIABLE TRANSPORTATION | | | SCAC3 |
| 5510 | RLIB | REA LOGISTICS INC | | | SCAC4 |
| 5511 | RLIC | RELIANCE LOGISTICS INC | | | SCAC4 |
| 5512 | RLID | RED LEAF INTERNATIONAL INC | | | SCAC4 |
| 5513 | RLIE | R.L.E. EXPRESS, INC | | | SCAC3 |
| 5514 | RLIE | ROCHI LOGISTICS INC | | | SCAC4 |
| 5515 | RLIF | ROWE LOGISTICS INC | | | SCAC4 |
| 5516 | RLIJ | RELIANCE LOGISTICS INC | | | SCAC4 |
| 5517 | RLIM | RAILPORT LOGISTICS INC | | | SCAC4 |
| 5518 | RLIN | REAL INDUSTRIES USA | | | SCAC4 |
| 5519 | RLIO | RICH LINK INTL LOGISTICS SERVICE (S | | | SCAC4 |
| 5520 | RLIP | ROOSTER LIPS COMPANY INC | | | SCAC4 |
| 5521 | RLIQ | RPM LOGISTICS INC | | | SCAC4 |
| 5522 | RLIS | ROYAL LIMOUSINE SERVICE INC | | | SCAC3 |
| 5523 | RLIS | RODVAL LOGISTIC INC | | | SCAC4 |
| 5524 | RLIT | RED LINE TRUCK LINE | | | SCAC3 |
| 5525 | RLIW | RUGGED LINER INC | | | SCAC4 |
| 5526 | RLIX | Rail Link Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 5527 | RLIX | Rail Link Inc. | Jul-00 | | NRHS |
| 5528 | RLIX | RAIL LINK, INC. | | | PWRC |
| 5529 | RLIX | Rail Link | | | RSRV |
| 5530 | RLIX | RAIL LINK, INC. | | | SCAC4 |
| 5531 | RLIX | Rail Link | | USA | TRAFFIC |
| 5532 | RLIY | ROSEN LOGISTICS INC | | | SCAC4 |
| 5533 | RLJ | Empyreal Jet, Inc. | Callsign: Real Jet, Founded 14 January 2019. | USA | AVCODES |
| 5534 | RLJI | R L & J VENTURES INC | | | SCAC4 |
| 5535 | RLJK | RALEIGH JUNK CO | | | SCAC3 |
| 5536 | RLK | Air Nelson Ltd. | Callsign: Link, | NZ | AVCODES |
| 5537 | RLK | Air Nelson | | | ICAO1 |
| 5538 | RLK | RaiLink Canada Ltd, d/b/a RaiLink Ottawa Valley | added 7/1998; 7/2000; eliminated 1/2003; 7/2005 | | NAKINA |
| 5539 | RLK | RaiLink Canada Ltd, d/b/a RaiLink Ottawa Valley | added 7/98; 7/2000 | | NRHS |
| 5540 | RLK | RAILINK CANADA LIMITED d/b/a RAILINK OTTAWA VALLEY | | | PWRC |
| 5541 | RLK | Rail Link | | | RSRV |
| 5542 | RLK | RAILINK OTTAWA VALLEY | | | SCAC4 |
| 5543 | RLKC | ROCK LAKE CUSTOM SERVICES LLC | | | SCAC4 |
| 5544 | RLKF | RLK TRANSFER INC | | | SCAC3 |
| 5545 | RLKG | R L TRUCKING INC | | | SCAC3 |
| 5546 | RLKG | RECOL TRUCKING INC | | | SCAC4 |
| 5547 | RLKI | R L K INC | | | SCAC3 |
| 5548 | RLKI | R & L TRUCKING LLC | | | SCAC4 |
| 5549 | RLKL | ROADLINK TRANSPORTATION SOLUTIONS | | | SCAC4 |
| 5550 | RLKO | RAINY LAKE OIL | | | SCAC4 |
| 5551 | RLKP | RUNA LINK CORP | | | SCAC4 |
| 5552 | RLKQ | RICHMOND LINK & SONS | | | SCAC3 |
| 5553 | RLKX | R.L. and S.S. Klein | added 4/1984; eliminated 4/1985 | | NAKINA |
| 5554 | RLKX | Delta Tank Line Co. | added 1/1984; eliminated 4/1984 | | NAKINA |
| 5555 | RLKX | R.L. and S.S. Klein | added 4/84; eliminated 4/85 | | NRHS |
| 5556 | RLKX | Delta Tank Line Co. | eliminated 4/84 | | NRHS |
| 5557 | RLKX | R. L. & S. S. KLEIN | | | PWRC |
| 5558 | RLKX | R. L. and S. S. Klein | | | RSRV |
| 5559 | RLL | Air Leone Company Ltd. | Callsign: Aeroleone, | WAL | AVCODES |
| 5560 | RLL | Air Leone | | | ICAO1 |
| 5561 | RLLA | RELLA & SON TRUCKING | | | SCAC3 |
| 5562 | RLLA | R LOGISTICS LLC | | | SCAC4 |
| 5563 | RLLC | RELIANCE LOGISTICS INC | | | SCAC4 |
| 5564 | RLLD | RENATA LOGISTICS LIMITED | | | SCAC4 |
| 5565 | RLLE | R & | | | SCAC4 |
| 5566 | RLLG | ROAD LINER LOGISTICS INC | | | SCAC4 |
| 5567 | RLLH | RL LOGISTICS | | | SCAC4 |
| 5568 | RLLI | ROLLINS TRANSPORTATION SYSTEMS INC | | | SCAC3 |
| 5569 | RLLM | ROYAL LIMOUSINE INC | | | SCAC3 |
| 5570 | RLLN | ROLLINS TRANSPORT CO | | | SCAC3 |
| 5571 | RLLN | ROLLING OATS LTD | | | SCAC4 |
| 5572 | RLLO | ROLLOUT EXPRESS INC | | | SCAC3 |
| 5573 | RLLO | ROAD LOADS LLC | | | SCAC4 |
| 5574 | RLLQ | RELOTRANS LLC | | | SCAC4 |
| 5575 | RLLR | REDLINE LLC | | | SCAC4 |
| 5576 | RLLS | RIVERSIDE LOGISTICS LLC | | | SCAC4 |
| 5577 | RLLT | RUSSELL, T & CO TRUCKING | | | SCAC4 |
| 5578 | RLLV | RODE LOGISTICS LTD | | | SCAC4 |
| 5579 | RLLY | REILLY CARTAGE INC | | | SCAC3 |
| 5580 | RLM | Royal American Airways | Callsign: Royal American, | USA | AVCODES |
| 5581 | RLM | Royal American Airways | | | ICAO1 |
| 5582 | RLM | REGENCY LIMOUSINE INC | | | SCAC4 |
| 5583 | RLMA | RAIL MASTERS INC | | | SCAC3 |
| 5584 | RLMC | RLM ENTERPRISES | | | SCAC4 |
| 5585 | RLMD | REALM INDUSTRIES CORP | | | SCAC4 |
| 5586 | RLMG | RILEY MANUFACTURING | | | SCAC4 |
| 5587 | RLMI | REALM INC | | | SCAC4 |
| 5588 | RLMO | RED LINE MOVING CO INC | | | SCAC3 |
| 5589 | RLMQ | REEL TIME TACTICAL LOGISTICS LLC | | | SCAC4 |
| 5590 | RLMS | RELIABLE MOVING & STORAGE INC | | | SCAC3 |
| 5591 | RLMS | RAILSIDE LOCOMOTIVE SERVICES | | | SCAC4 |
| 5592 | RLMT | RELIANCE MARINE TRANSPORTATION AND | | | SCAC3 |
| 5593 | RLMX | The David J. Joseph Co. | added 10/2003; 7/2005; eliminated 1/2009 | | NAKINA |
| 5594 | RLMX | Joseph Transportation Inc. | added 4/2000; 7/2000; eliminated 10/2003 | | NAKINA |
| 5595 | RLMX | The David J. Joseph Co. | added 1/1990; 1/1994; eliminated 4/2000 | | NAKINA |
| 5596 | RLMX | The David J. Joseph Co. | added 1/90; 1/94; eliminated 4/2000 | | NRHS |
| 5597 | RLMX | Joseph Transportation Inc. | added 4/2000; 7/2000 | | NRHS |
| 5598 | RLMX | DAVID J. JOSEPH COMPANY (JOSEPH TRANSPORTATION INC.) | | | PWRC |
| 5599 | RLMX | Joseph Transportation | | | RSRV |
| 5600 | RLN | Ruslan Airline | Callsign: Ruslan, | KZ | AVCODES |
