| 1 | MBT | Vias Aereas Manabitas CIA Ltda. | Callsign: Manabitas, | EC | AVCODES |
| 2 | MBT | Province of Manitoba, Air Services Branch | Callsign: Manitoba, | CDN | AVCODES |
| 3 | MBT | Marianna & Blountstown R.R. Co. | added 11/1973; 1/1975; eliminated 1/1976; 1/1980 | | NAKINA |
| 4 | MBT | Marianna & Blountstown R.R. Co. | added 11/73; 1/75-1/80 | | NRHS |
| 5 | MBT | MARIANA & BLOUNTSTOWN RAILROAD CO. | | | PWRC |
| 6 | MBT | Marianna and Blountstown Railroad | | | RSRV |
| 7 | MBTA | *M & B TRANSPORT INC. | | | PWRC |
| 8 | MBTA | *MASSACHUSETTS BAY TRANSIT AUTHORITY | | | PWRC |
| 9 | MBTA | M B T TRANSPORT INC | | | SCAC4 |
| 10 | MBTA | Massachusetts Bay Transportation Authority | | USA | TRAFFIC |
| 11 | MBTB | MBT 2002 | | | SCAC4 |
| 12 | MBTC | M B T INC | | | SCAC4 |
| 13 | MBTE | M B TRANSPORT ENTERPRISES INC | | | SCAC4 |
| 14 | MBTF | MB2 LOGISTICS LLC | | | SCAC4 |
| 15 | MBTI | M B TRANSPORT INC | | | SCAC4 |
| 16 | MBTJ | MANGIARDI BROTHERS TRUCKING INC | | | SCAC4 |
| 17 | MBTK | MORROW, BILL TRUCKING | | | SCAC4 |
| 18 | MBTL | MAISLIN BROS TRANSP LTD | | | PWRC |
| 19 | MBTL | MCCOMBS TRANSPORT LLC | | | SCAC4 |
| 20 | MBTN | MACDONALD, BOB TRUCKING | | | SCAC4 |
| 21 | MBTO | MAL-B TRANSPORT INC | | | SCAC4 |
| 22 | MBTU | MULTIBOXX LIMITED | | HK | BIC |
| 23 | MBTX | Massachusetts Bay Transportation Authority | added 10/2002; 7/2005 | | NAKINA |
| 24 | MBTX | MASSACHUSETTS BAY TRANSPORTATION AUTHORITY | | | PWRC |
| 25 | MBTX | Massachusetts Bay Transportation Authority | | | RSRV |
| 26 | MBTX | MASSACHU | | | SCAC4 |
| 27 | MBTY | MBT TRANSPORT LLC | | | SCAC4 |
