| 7701 | MRXI | MUROX INDUSTRIES LTD | | | SCAC4 |
| 7702 | MRXK | MUNRO TRANSPORT LTD | | | SCAC4 |
| 7703 | MRXL | MATRIX INTERNATIONAL LOGISTICS INC | | | SCAC4 |
| 7704 | MRXP | MARX TRANSPORT INC | | | SCAC4 |
| 7705 | MRXR | MOORES TRANSPORT LLC | | | SCAC4 |
| 7706 | MRXS | MATRIX SCALE SERVICE INC | | | SCAC4 |
| 7707 | MRXT | MOLNAR TRANSPORT INC | | | SCAC4 |
| 7708 | MRXW | MARTINS REFRIGERATED EXPRESS INC | | | SCAC4 |
| 7709 | MRXY | MORIN TRANSFER | | | SCAC4 |
| 7710 | MRY | Murray Air, Inc. | Callsign: Murray Cargo, In December 2008, after the airline was acquired by National Air Cargo, Murray Air changed its name to National Airlines and operates under the National Air Cargo Group. | USA | AVCODES |
| 7711 | MRY | Air Marine | Callsign: Air Marine, | F | AVCODES |
| 7712 | MRYA | MCRAY CRANE & RIGGING INC | | | SCAC4 |
| 7713 | MRYC | MERCURY TRANSPORT INC | | | SCAC4 |
| 7714 | MRYE | MANRAY EXPRESS | | | SCAC4 |
| 7715 | MRYG | MRS RECYCLING | | | SCAC4 |
| 7716 | MRYL | MARYN INTERNATIONAL LTD | | | SCAC4 |
| 7717 | MRYP | MURRAY TRANSPORT | | | SCAC4 |
| 7718 | MRYT | MILNER, RAYMOND TRUCKING | | | SCAC4 |
| 7719 | MRYV | MARYSVI | | | SCAC4 |
| 7720 | MRYY | MONTEREY COUNTY PETROLEUM | | | SCAC4 |
| 7721 | MRZ | Medical Air Rescue Services (MARS) | Callsign: Mars, | ZW | AVCODES |
| 7722 | MRZ | Medical Air Rescue Services | | | ICAO1 |
| 7723 | MRZA | MARZA TRUCKING INC | | | SCAC4 |
| 7724 | MRZC | MRZ TRUCKING CORP | | | SCAC4 |
| 7725 | MRZE | MARTINEZ, ZENAIDO JR TRUCKING LLC | | | SCAC4 |
| 7726 | MRZU | MARENZANA SPA | | I | BIC |
| 7727 | MRZU | MARENZANA SPA | | | SCAC4 |
| 7728 | MS | Egyptair | ICAO: MSR, Callsign: Egyptair, IATA Prefix: 077, Name changed from United Arab Airlines (UAA). ICAO designator changed form EGY | ET | AVCODES |
| 7729 | MS | United Arab Airlines (UAA) | Name changed to Egypt Air | ET | AVCODES |
| 7730 | MS | Egypt Air | ICAO: EGY, Callsign: Egyptair, IATA Prefix: 077, Name changed to Egyptair. ICAO designator changed to MSR. Name changed from United Arab Airlines (UAA) | ET | AVCODES |
| 7731 | MS | Michigan Shore R.R., Inc. | added 7/1991; 1/1994-7/2005 | | NAKINA |
| 7732 | MS | Missouri Southern R.R. Co. | 8/1920-1/1952 | | NAKINA |
| 7733 | MS | Missouri Southern R.R. Co. | 4/38-1/52 | | NRHS |
| 7734 | MS | Michigan Shore R.R., Inc. | added 7/91; 1/94-7/2000 | | NRHS |
| 7735 | MS | *MISSOURI SOUTHERN RAILROAD CO. | | | PWRC |
| 7736 | MS | +MICHIGAN SHORE RAILROAD, INC. | | | PWRC |
| 7737 | MS | Michigan Shore Railroad | | | RSRV |
| 7738 | MS | MICHIGAN SHORE RAILROAD INC | | | SCAC4 |
| 7739 | MSA | Mistral Air Srl | Callsign: Airmerci, ICAO callsign changed to Mistral Wings | I | AVCODES |
| 7740 | MSA | Mid-South Commuter Airlines | Callsign: Mid-South, | USA | AVCODES |
| 7741 | MSA | Mistral Air S.r.l. | IATA: 7M, Callsign: Mistral Wings, IATA Designator changed to M4. ICAO callsign changed from Aiemerci | I | AVCODES |
| 7742 | MSA | Mistral Air Srl | ICAO callsign changed to Aiemerci | I | AVCODES |
| 7743 | MSA | Mistral Air S.r.l. | IATA: M4, Callsign: Mistral Wings, Name changed to Poste Air Cargo S.r.l. October 2019. IATA Designator changed from 7M. ICAO callsign changed from Aiemerci | I | AVCODES |
| 7744 | MSA | Poste Air Cargo S.r.l. | IATA: M4, Callsign: Mistral Wings, IATA Prefix: 408, Name changed from Mistral Air S.r.l. October 2019. IATA Designator changed from 7M. ICAO callsign changed from Aiemerci | I | AVCODES |
| 7745 | MSA | Mistral Air | | | ICAO1 |
| 7746 | MSA | Mistral Air | Renamed to Poste Air Cargo in 2019 | I | TRAFFIC |
| 7747 | MSAA | M S T S | | | SCAC4 |
| 7748 | MSAB | MID SOUTH TRANSPORTATION LLC | | | SCAC4 |
| 7749 | MSAC | MONT-SAINTE-ANNE | | | SCAC4 |
| 7750 | MSAF | MOUNTAIN SPRINGS SPAS | | | SCAC4 |
| 7751 | MSAG | MOTION CONCEPTS LP | | | SCAC4 |
| 7752 | MSAH | MS TRANS | | | SCAC4 |
| 7753 | MSAJ | MSA DELIVERY SERVICE | | | SCAC4 |
| 7754 | MSAL | MARITIME SERVICES ALEUROPA GMBH | | | SCAC4 |
| 7755 | MSAP | MODEVATION ENTERPRISES INC | | | SCAC4 |
| 7756 | MSAQ | MORRIS LOGISTICS LLC | | | SCAC4 |
| 7757 | MSAR | MS BLACK SHEEP TRUCKING COMPANY INC | | | SCAC4 |
| 7758 | MSAS | MARTINEZ SOSA, ANTONIO Y SILVA | | | SCAC4 |
| 7759 | MSAU | MAERSK A/S | | DK | BIC |
| 7760 | MSAU | A P MOLLER | | | SCAC4 |
| 7761 | MSAV | M & S TRUCKING CO | | | SCAC4 |
| 7762 | MSAY | MILLTOWN COLONY FARMS LTD | | | SCAC4 |
| 7763 | MSAZ | NATIONAL MOTOR FREIGHT TRAFFIC ASSOCIATION | | | PWRC |
| 7764 | MSAZ | National Motor Freight Traffic Association | | | RSRV |
| 7765 | MSB | CA Air Stork SRL | IATA: 0S, Callsign: Long, IATA designator changed to 2S*. | MD | AVCODES |
| 7766 | MSB | CA Air Stork SRL | IATA: 2S, Callsign: Long, IATA designator changed from 0S*. | MD | AVCODES |
| 7767 | MSBA | Metropolitan Suburban Bus Authority | | USA | TRAFFIC |
| 7768 | MSBB | MS TRANSPORTES | | | SCAC4 |
| 7769 | MSBC | MASTERLEAS | | | SCAC4 |
| 7770 | MSBG | MARITIME SERVICES LINE ARGENTINA S | | | SCAC4 |
| 7771 | MSBM | M & S BLASTING LLC | | | SCAC4 |
| 7772 | MSBN | MIKES PRODUCE | | | SCAC4 |
| 7773 | MSBP | Muscle Shoals, Birmingham & Pensacola Ry. Co. | 7/1923 | | NAKINA |
| 7774 | MSBP | MUSCLE SHOALS, BIRMINGHAM & PENSACOLA RWY. CO. | | | PWRC |
| 7775 | MSBQ | MIDAME | | | SCAC4 |
| 7776 | MSBR | T L MOSBRUCKER & SON | | | SCAC3 |
| 7777 | MSBT | MISSISSIPPI BULK TRANSPORT INC | | | SCAC4 |
| 7778 | MSBU | MSC- MEDITERRANEAN SHIPPING COMPANY S.A. | | CH | BIC |
| 7779 | MSBV | MORGAN STANLEY CAPITAL GROUP INC | | | SCAC4 |
| 7780 | MSBW | MANBECK | | | SCAC4 |
| 7781 | MSBY | MOSBYS INC | | | SCAC4 |
| 7782 | MSC | Moscow Airways | IATA: M8, | RUS | AVCODES |
| 7783 | MSC | Air Cairo | IATA: CE, IATA Prefix: 381, IATA designator changed to SM. Founded in 2003 | ET | AVCODES |
| 7784 | MSC | Air Cairo | IATA: SM, IATA Prefix: 381, IATA designator changed to SM. Founded in 2003 | ET | AVCODES |
| 7785 | MSC | Air Cairo | | | ICAO1 |
| 7786 | MSC | Mississippi Central R.R. | 8/1920-10/1966 | | NAKINA |
| 7787 | MSC | Illinois Central Gulf R.R. | 1/1975-1/1980 | | NAKINA |
| 7788 | MSC | Mississippi Central R.R. | 4/38-10/66 | | NRHS |
| 7789 | MSC | Illinois Central Gulf R.R. | 1/75-1/80 | | NRHS |
| 7790 | MSC | *ILLIONOS CENTRAL GULF RAILROAD [MISSISSIPPI CENTRAL RAILROAD COMPANY] | | | PWRC |
| 7791 | MSC | *MONITOR SUGAR | | | PWRC |
| 7792 | MSC | Mississippi Central (Illinois Central Gulf Railroad) | | | RSRV |
| 7793 | MSC | MASTERS COACH LTD, THE | | | SCAC4 |
| 7794 | MSCC | M S CARRIERS | | | SCAC1 |
| 7795 | MSCC | MOBILE SATELLITE CONNECTION LLC | | | SCAC4 |
| 7796 | MSCD | M L S CARRIERS INC | | | SCAC4 |
| 7797 | MSCE | MARTIN STORAGE CO INC | | | SCAC4 |
| 7798 | MSCF | MARCONSULT SCHIFFAHRT GMBH & CO KG | | | SCAC4 |
| 7799 | MSCG | MULTI SCALE CHARGE LTD | | | SCAC4 |
| 7800 | MSCH | MEUNERIE ST-CHRYSOSTOME INC | | | SCAC4 |
