| 1 | MRC | Medical Air Rescue | Callsign: Rescue, | E | AVCODES |
| 2 | MRC | Airmarc Airlines, Inc. | Callsign: Airmarc, | USA | AVCODES |
| 3 | MRC | Martin Companies | Callsign: Martrans, | USA | AVCODES |
| 4 | MRC | Michigan R.R. Co. | 7/1923 | | NAKINA |
| 5 | MRC | *MICHIGAN RAILROAD CO. | | | PWRC |
| 6 | MRC | *MONROE RAILROAD COMPANY | | | PWRC |
| 7 | MRC | METRO CAB INC | | | SCAC4 |
| 8 | MRC | Manufacturers Ry. Co. of St. Louis | Real: MRS | USA | TRAFFIC |
| 9 | MRCA | MARCOS CALIDAD S A DE C V | | | SCAC4 |
| 10 | MRCD | MERCHANTS DELIVERY | | | SCAC1 |
| 11 | MRCD | MERCHANTS DELIVERY INC | | | SCAC4 |
| 12 | MRCE | Mitsui Rail Capital Europe B.V. | Amsterdam NL | D | privat-bahn.de |
| 13 | MRCE | MAURER CONSTRUCTION LTD | | | SCAC4 |
| 14 | MRCE | Mitsui Rail Company Europe | | NL | TRAFFIC |
| 15 | MRCEDL | MRCE Dispolok | | EU | TRAFFIC |
| 16 | MRCF | MORRISON CUSTOM FEEDS INC | | | SCAC4 |
| 17 | MRCG | MARROCO TRUCKING INC | | | SCAC4 |
| 18 | MRCI | MARTINEZ CRUZ, ISRAEL | | | SCAC4 |
| 19 | MRCJ | MARTIN, CHRIS (STERNDRIVE SPECIALIS | | | SCAC4 |
| 20 | MRCK | MRC TRUCKING LLC | | | SCAC4 |
| 21 | MRCM | MASON, R C MOVERS INC | | | SCAC4 |
| 22 | MRCN | MR TRUCKING | | | SCAC4 |
| 23 | MRCO | MADISON RAILWAY COMPANY | | | PWRC |
| 24 | MRCO | MARCOTTE DISPOSAL COMPANY | | | SCAC4 |
| 25 | MRCS | MORRISON RAIL CAR SERVICE OPERATION | | | PWRC |
| 26 | MRCT | MRC TRANSPORT INC | | | SCAC4 |
| 27 | MRCU | {LLC "EMRCC"};ZIPCODE=197046 | | RUS | BIC |
| 28 | MRCU | MERCATOR SHIPPING | | | SCAC1 |
| 29 | MRCW | MARINE CROSS COUNTRY INC | | | SCAC4 |
| 30 | MRCX | General Electric Rail Services Corp. | added 1/2000; 7/2000-7/2005 | | NAKINA |
| 31 | MRCX | General Electric Railcar Services Corp. | added 10/1992; 1/1994; eliminated 1/2000 | | NAKINA |
| 32 | MRCX | Itel Rail Corp. | added 4/1988; eliminated 10/1992 | | NAKINA |
| 33 | MRCX | Evans Railcar Leasing Co. | added 10/1980; eliminated 4/1988 | | NAKINA |
| 34 | MRCX | United States Railway Leasing Co. | added 4/1980; eliminated 10/1980 | | NAKINA |
| 35 | MRCX | Morrison Railway Supply Corp. | added 4/1969; 4/1970-1/1980; eliminated 4/1980 | | NAKINA |
| 36 | MRCX | Metals Reserve Co., care of Tin Processing Corp. | 1/1943 | | NAKINA |
| 37 | MRCX | Merck & Co., Inc. | 7/1932 | | NAKINA |
| 38 | MRCX | Morrison Railway Supply Corp. | added 4/69; 4/70-1/80; eliminated 4/80 | | NRHS |
| 39 | MRCX | United States Railway Leasing Co. | added 4/80; eliminated 10/80 | | NRHS |
| 40 | MRCX | Evans Railcar Leasing Co. | added 10/80; eliminated 4/88 | | NRHS |
| 41 | MRCX | Itel Rail Corp. | added 4/88; eliminated 10/92 | | NRHS |
| 42 | MRCX | General Electric Railcar Services Corp. | added 10/92; 1/94; eliminated 1/2000 | | NRHS |
| 43 | MRCX | General Electric Rail Services Corp. | added 1/2000; 7/2000 | | NRHS |
| 44 | MRCX | *MERCK & CO., INC. | | | PWRC |
| 45 | MRCX | *METALS RESERVE CO. (TIN PROCESSING CORP.) | | | PWRC |
| 46 | MRCX | +(NATX) GEN. ELECTRIC RAILCAR SERVICES CORP. [ITEL RAIL CORP.; EVANS RAILCAR LEASING CO.; UNITED STATES RAILWAY LEASING CO.; MINER RAIL CAR SERVICE; MORRISON RAILWAY SUPPLY CORP.] | | | PWRC |
| 47 | MRCX | Evans Railcar Leasing (GE Rail Services Corporation) | | | RSRV |
| 48 | MRCX | GENERAL ELECTRIC RAILCAR SERVICES C | | | SCAC4 |
| 49 | MRCY | MERCURY TRANSPORTATION SOLUTIONS | | | SCAC4 |
| 50 | MRCZ | MOORMAN COMPANY | | | PWRC |
| 51 | MRCZ | MONARCH TRANSPORT LLC | | | SCAC4 |
