| 1 | MDA | Mandarin Airlines Ltd. | IATA: AE, Callsign: Mandarin, IATA Prefix: 803, | RC | AVCODES |
| 2 | MDA | Mandarin Airlines | IATA: AE | | ICAO1 |
| 3 | MDAA | MD TRUCKING | | | SCAC4 |
| 4 | MDAC | MIDDLE ATLANTIC PRODUCTS INC | | | SCAC4 |
| 5 | MDAD | MIDDLEBURG PROPERTIES LIMITED | | | SCAC4 |
| 6 | MDAD | Miami Dade Aviation Department | | USA | TRAFFIC |
| 7 | MDADE | Miami-Dade Transit | | USA | TRAFFIC |
| 8 | MDAE | MARTINEZ, DORA E | | | SCAC4 |
| 9 | MDAF | MID AMERICA FREIGHT SYSTEMS LTD | | | SCAC4 |
| 10 | MDAI | MAINLAND TRANSPORT LTD | | | SCAC4 |
| 11 | MDAM | M & D TRUCKING CO INC | | | SCAC4 |
| 12 | MDAO | MID-ATLANTIC LOGISTICS COMPANY | | | SCAC4 |
| 13 | MDAQ | MDI TRANSPORTATION SYSTEMS INC | | | SCAC4 |
| 14 | MDAS | MIDAS EXPRESS, INC | | | SCAC1 |
| 15 | MDAS | MIDWAY TRANSPORTATION INC | | | SCAC4 |
| 16 | MDAU | MEDAFRICA LINE S P A | | | SCAC4 |
| 17 | MDAW | MODEL DAIRY LLC | | | SCAC4 |
| 18 | MDAX | Merchants Despatch Transportation Co. | added 1/1962; 7/1965-1/1980; eliminated 7/1985 | | NAKINA |
| 19 | MDAX | Merchants Despatch Transportation Co. | added 1/62; 7/65-1/80 | | NRHS |
| 20 | MDAX | MERCHANTS DESPATCH TRANSPORTATION CORP. | | | PWRC |
| 21 | MDAX | Merchants Despatch Transportation Corporation | | | RSRV |
| 22 | MDAY | MOLIVA DENIZCILIK AS | | | SCAC4 |
| 23 | MDAZ | MERIDIAN AGGREGATES | | | PWRC |
