| 1 | MRB | Centre Pankh Kazakhstan | Callsign: Toma, | KZ | AVCODES |
| 2 | MRB | Mitteldeutsche Regiobahn | Leipzig (Veolia-Verkehr Regio Ost) | D | privat-bahn.de |
| 3 | MRB | Mitteldeutsche Regiobahn | | D | TRAFFIC |
| 4 | MRBC | M & R TRUCK BROKERS | | | SCAC4 |
| 5 | MRBD | MURRAY, D B LTD | | | SCAC4 |
| 6 | MRBE | MIRABELLI, P J ENTERPRISES INC | | | SCAC4 |
| 7 | MRBH | MCEVE | | | SCAC4 |
| 8 | MRBJ | MOST RELIABLE COURIER INC | | | SCAC4 |
| 9 | MRBL | M & R TRANSPORTATION LLC | | | SCAC4 |
| 10 | MRBM | M & R TRUCKING | | | SCAC4 |
| 11 | MRBN | MORENO BENITEZ, EDIEL | | | SCAC4 |
| 12 | MRBO | MRB TRANSPORT INC | | | SCAC4 |
| 13 | MRBQ | M C & S TRANSPORT LTD | | | SCAC4 |
| 14 | MRBR | MR BROTHERS INC | | | SCAC4 |
| 15 | MRBT | MIRABITO, JAMES & SONS | | | SCAC4 |
| 16 | MRBU | GERMAN AEROSPACE CENTER | | D | BIC |
| 17 | MRBU | DEUTSCHES ZENTRUM FUR LUFT UND RAUM | | | SCAC4 |
| 18 | MRBV | MACLEANS READY MIX CONCRETE LTD | | | SCAC4 |
| 19 | MRBW | MAGRABBIT DEDICATED FLEET LLC | | | SCAC4 |
| 20 | MRBX | Merchants Despatch Transportation Co. | added 10/1953; 7/1954-4/1970; eliminated 7/1970 | | NAKINA |
| 21 | MRBX | Merchants Despatch Transportation Co. | added 10/53; 10/57-4/70; eliminated 7/70 | | NRHS |
| 22 | MRBX | MERCHANTS DESPATCH TRANSPORTATION CORP. | | | PWRC |
| 23 | MRBY | MUEBLES RUSTICOS BERNAL | | | SCAC4 |
