| 301 | RMMI | Reggia Marina Militare Italiana | | I | TRAFFIC |
| 302 | RMMO | RADIGAN & MCGILLY MOVING SERVICE IN | | | SCAC3 |
| 303 | RMMO | RAMIREZ, MARIO | | | SCAC4 |
| 304 | RMMS | RAM MESSENGER SERVICE LTD | | | SCAC3 |
| 305 | RMMT | R A M TRANSPORTATION INC | | | SCAC3 |
| 306 | RMMT | ROMAN SC INC | | | SCAC4 |
| 307 | RMMU | EMERSON CLIMATE TECHNOLOGIES | | DK | BIC |
| 308 | RMMU | YORK REFRIGERATION MARINE AND CONTR | | | SCAC4 |
| 309 | RMMV | RAYS MACHINERY MOVERS | | | SCAC3 |
| 310 | RMMX | The Andersons-Rail Group | added 10/2004; 7/2005 | | NAKINA |
| 311 | RMMX | Railcar, Ltd. | added 4/1994; 7/2000; eliminated 10/2004 | | NAKINA |
| 312 | RMMX | Railcar, Ltd. | added 4/94; 7/2000 | | NRHS |
| 313 | RMMX | THE ANDERSONS-RAIL GROUP [(RMGX) RAILCAR LIMITED] | | | PWRC |
| 314 | RMMX | Railcar Limited | | | RSRV |
| 315 | RMMX | ANDERSONS INC, THE | | | SCAC4 |
| 316 | RMN | RM Aviation Ltd. | Callsign: Roman, | GB | AVCODES |
| 317 | RMN | Classic Flight Training Services Ltd | Callsign: Rainman, Ceased operations. | GB | AVCODES |
| 318 | RMNC | ROCKY MOUNTAIN COMPANY | | | SCAC3 |
| 319 | RMNC | RMC FOODS INC | | | SCAC4 |
| 320 | RMND | RAMSAN | | | SCAC4 |
| 321 | RMNG | R & M TRUCKING | | | SCAC3 |
| 322 | RMNG | RM TRUCKING INC | | | SCAC4 |
| 323 | RMNI | ROMAIN TRANSPORT | | | SCAC4 |
| 324 | RMNL | RUEBUSH, LARRY TRUCKING INC | | | SCAC3 |
| 325 | RMNL | RAMOS, MANUEL A | | | SCAC4 |
| 326 | RMNR | RMS TRANSPORT | | | SCAC4 |
| 327 | RMNS | R M TRUCKING & STORAGE | | | SCAC4 |
| 328 | RMNT | RICHMOND TRANSPORT INC | | | SCAC3 |
| 329 | RMNY | ROMNEY BENTLEY, RULON KENT | | | SCAC4 |
| 330 | RMNZ | CSX TRANSPORTATION, INC. | | | PWRC |
| 331 | RMO | Rybinsk Motors, Joint-Stock Company | Callsign: Rybmotors, | RUS | AVCODES |
| 332 | RMO | Arm-Aero | Callsign: Arm-Aero, | AM | AVCODES |
| 333 | RMO | Arm-Aero | | | ICAO1 |
| 334 | RMOA | ROMA | | | SCAC4 |
| 335 | RMOB | RUSS'S MOBILE HOME SERVICE | | | SCAC3 |
| 336 | RMOB | REDBIRD MOTOR | | | SCAC4 |
| 337 | RMOC | RAMSEY OIL CO INC | | | SCAC3 |
| 338 | RMOD | ROBALI MOTORSPORTS | | | SCAC4 |
| 339 | RMOI | R & M OIL & SUPPLY INC | | | SCAC4 |
| 340 | RMOL | ROMINE OIL | | | SCAC3 |
| 341 | RMOL | ROMINE OIL COMPANY | | | SCAC4 |
| 342 | RMOM | RACHLES/MI | | | SCAC4 |
| 343 | RMON | RAINBOW MOVING AND STORAGE INC | | | SCAC4 |
| 344 | RMOO | RAMCON TRANSPORTATION | | | SCAC4 |
| 345 | RMOP | REMO ENTERPRISE INC OF LIBERIA | | | SCAC3 |
| 346 | RMOQ | RMORMES TRANSPORTATION INC | | | SCAC3 |
| 347 | RMOR | ROMA TRANSPORT INC | | | SCAC4 |
| 348 | RMOS | RAMOS TRUCK LINE | | | SCAC3 |
| 349 | RMOT | RILEY MOTORSPORTS | | | SCAC4 |
| 350 | RMOV | RAMOS MOVERS INC | | | SCAC3 |
| 351 | RMP | Servicios de Rampa Y Mostrador, S.A. de C.V. | Callsign: Seramsa, | MEX | AVCODES |
| 352 | RMP | Servicios De Rampa Y Mostrador | | | ICAO1 |
| 353 | RMPA | R M P & ASSOCIATES INC | | | SCAC3 |
| 354 | RMPB | RELATIONSHIPS MATTER PUBLISHING INC | | | SCAC4 |
| 355 | RMPD | RATION MAKER PRODUCTS SOUTH INC | | | SCAC3 |
| 356 | RMPD | RH MFG / PEDRO ZARAGOZA | | | SCAC4 |
| 357 | RMPE | RAPTOR MINING PRODUCTS INC | | | SCAC4 |
| 358 | RMPG | RAMPAGE ENTERPRISES INC | | | SCAC4 |
| 359 | RMPN | ROMERO PENA, FRANCISCO (MX-469948) | | | SCAC4 |
| 360 | RMPQ | REGIONAL MUNICIPALITY OF PEEL | | | SCAC3 |
| 361 | RMPQ | ROCKY MOUNTAIN PROPANE EXPRESS INC | | | SCAC4 |
| 362 | RMPR | RAMSEY PISTON RING CO | | | SCAC3 |
| 363 | RMPR | RM PRODUCE | | | SCAC4 |
| 364 | RMPS | RAMPLA SHIPPING COMPANY LIMITED | | | SCAC3 |
| 365 | RMPS | ROMA EXPRESS | | | SCAC4 |
| 366 | RMPV | RAM TRANSPORTATION SERVICES INC | | | SCAC4 |
| 367 | RMPX | Progress Rail Services Corp. | added 10/2004; 7/2005 | | NAKINA |
| 368 | RMPX | Railcar, Ltd. | added 4/2000; 7/2000; eliminated 10/2004 | | NAKINA |
| 369 | RMPX | Railcar, Ltd. | added 4/2000; 7/2000 | | NRHS |
| 370 | RMPX | PROGRESS RAIL SERVICES CORP. [RAILCAR, LTD.] | | | PWRC |
| 371 | RMPX | Progress Rail Services Corporation (Railcar Ltd) | | | RSRV |
| 372 | RMPX | PROGRESS RAIL SERVICES CORPORATION | | | SCAC4 |
| 373 | RMPY | RIMPYS TRANSPORT LTD | | | SCAC4 |
| 374 | RMPZ | *READY MIX PLANT | | | PWRC |
| 375 | RMPZ | *TRANSAMERICA LEASING INC [(REAZ) MISSOURI PACIFIC RAILROAD] | | | PWRC |
| 376 | RMPZ | TAL International | | | RSRV |
| 377 | RMPZ | TRANSAMERICA LEASING, INC. | | | SCAC4 |
| 378 | RMQ | Air Armorique | Callsign: Airmorique, | F | AVCODES |
| 379 | RMQF | R & M FARMS | | | SCAC4 |
| 380 | RMQN | RAMTIN COMPANY S A | | | SCAC3 |
| 381 | RMQT | RACINE, MAX TRUCKING | | | SCAC3 |
| 382 | RMQT | RAM TRANSPORT | | | SCAC4 |
| 383 | RMR | Romaero Ltd. | Callsign: Romaero, | RO | AVCODES |
| 384 | RMRA | RADIATEUR MONTREAL RADIATOR INC | | | SCAC4 |
| 385 | RMRB | RIEMER BROS INC | | | SCAC3 |
| 386 | RMRB | RAMIREZ BROS | | | SCAC4 |
| 387 | RMRD | RAM ROD TRUCKING & STORAGE INC | | | SCAC3 |
| 388 | RMRD | ROMERO, MARISCOS | | | SCAC4 |
| 389 | RMRF | REIMER FARM SUPPLIES LTD | | | SCAC3 |
| 390 | RMRG | RICHARDS, MARK RACING | | | SCAC4 |
| 391 | RMRI | R & M TRANSPORTS INC | | | SCAC3 |
| 392 | RMRI | R M EXPRESS INC | | | SCAC4 |
| 393 | RMRO | RAM ROD TRUCKING | | | SCAC3 |
| 394 | RMRP | RO-MAR TRANSPORTATION SYSTEMS, INC | | | SCAC3 |
| 395 | RMRP | RO-MAR TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 396 | RMRR | Rocky Mountain Railcar and R.R., Inc. | added 10/1987; eliminated 1/1991; added 10/1991; 1/1994; eliminated 1/1997; 7/2000-7/2005 | | NAKINA |
| 397 | RMRR | Rocky Mountain Railcar and R.R., Inc. | added 10/87; eliminated 1/91; added 10/91; 1/94; eliminated 1/97; 7/2000 | | NRHS |
| 398 | RMRR | ROCKY MOUNTAIN RAILCAR & RAILROAD, INC | | | PWRC |
| 399 | RMRR | Rocky Mountain Railcar and Railroad | | | RSRV |
| 400 | RMRR | ROCKY MOUNTAIN RAILCAR AND RAILROAD | | | SCAC3 |
