| 701 | MAUU | MAURITIUS OIL REFINERIED LTD | | | SCAC4 |
| 702 | MAUY | MID AMERICA UNDERGROUND LLC | | | SCAC4 |
| 703 | MAV | Marina Aeroservice, S.A. | | E | AVCODES |
| 704 | MAV | Air Chaparral | Callsign: Maverick, | USA | AVCODES |
| 705 | MAV | Minoan Air | Callsign: Minoan, Founded on 07 September 2011. Ceased operations during November 2015. | GR | AVCODES |
| 706 | MAV | Manta Aviation Pvt. Ltd. | IATA: NR, Callsign: Sea Wing, Commenced operations on 24 February 2019. | MV | AVCODES |
| 707 | MAV | Magyar Államvasutak ZRt. | | HU | VKM |
| 708 | MAVC | MÁV Cargo | | H | TRAFFIC |
| 709 | MAVD | MAVI TRANSPORT INC | | | SCAC4 |
| 710 | MAVEP | Mávépcell Kft. | | H | TRAFFIC |
| 711 | MAVF | MALVERN | | | SCAC4 |
| 712 | MAVGS | MÁV-GÉPÉsZet Zrt. | | HU | VKM |
| 713 | MaVJ | Markaryd - Veinge Järnväg | 1899 - 1930 | S | svenska-lok.se |
| 714 | MAVK | MAVERICK LOGISTICS LLC | | | SCAC4 |
| 715 | MAVL | MAVERICK LOGISTICS | | | SCAC4 |
| 716 | MAVN | MURRAY AGRO-VENTURES INC | | | SCAC4 |
| 717 | MAVQ | MUSEUMP | | | SCAC4 |
| 718 | MAVR | MAVERICK CANADA LTD | | | SCAC4 |
| 719 | MAVRT | MÁV Rail Tours Kft. | | H | TRAFFIC |
| 720 | MAVS | MAVA SHIPPING CO LTD | | | SCAC4 |
| 721 | MAVS | MÁV Start | | H | TRAFFIC |
| 722 | MAVTR | MÁV-TRAKCIÓ Zrt. (MAV-TRACTION Co) | | HU | VKM |
| 723 | MAVU | MARITIMA ARAGUA LINE | | | SCAC4 |
| 724 | MAVW | MORAN AUTOMOTIVE & TOWING INC | | | SCAC4 |
| 725 | MAW | Mustique Airways | Callsign: Mustique, Designator Q4 recalled by IATA | WV | AVCODES |
| 726 | MAW | Mustique Airways | | | ICAO1 |
| 727 | MAW | Maumee & Western R.R. Corp. | added 7/1998; 7/2000-7/2005 | | NAKINA |
| 728 | MAW | Maumee & Western R.R. Corp. | added 7/98; 7/2000 | | NRHS |
| 729 | MAW | MAUMEE & WESTERN RAILROAD CORP. | | | PWRC |
| 730 | MAW | Maumee and Western Railroad | | | RSRV |
| 731 | MAW | MAUMEE & WESTERN RAILROAD CORPORATI | | | SCAC4 |
| 732 | MAWA | MASSA | | | SCAC4 |
| 733 | MAWC | M & A TRUCKING LLC | | | SCAC4 |
| 734 | MAWD | MADAWA | | | SCAC4 |
| 735 | MAWG | MEDINA AQUINO, REYNA CELESTE | | | SCAC4 |
| 736 | MAWJ | MARUBENI CORP | | | SCAC4 |
| 737 | MAWL | MARTINS ABATTOIR & WHOLESALE MEATS | | | SCAC4 |
| 738 | MAWN | MOBILE ASPHALT COMPANY INC | | | SCAC4 |
| 739 | MAWO | MANWEILER TRANSPORTS | | | SCAC4 |
| 740 | MAWP | MARITIME TRANSFER | | | SCAC4 |
| 741 | MAWS | MAWSON & MAWSON INC | | | SCAC4 |
| 742 | MAWW | MACOM | | | SCAC4 |
| 743 | MAWX | Olin Corp. | added 1/1970; 4/1970; eliminated 4/1973 | | NAKINA |
| 744 | MAWX | Olin Mathieson Chemical Corp. | added 10/1954; 10/1957-10/1966; eliminated 1/1970 | | NAKINA |
| 745 | MAWX | Mathieson Chemical Corp. | 1/1950-7/1954; eliminated 10/1954 | | NAKINA |
| 746 | MAWX | The Mathieson Alkali Works (Inc.) | 7/1937-4/1947 | | NAKINA |
| 747 | MAWX | Michigan Ammonia Works | 8/1920-7/1923 | | NAKINA |
| 748 | MAWX | The Mathieson Alkali Works (Inc.) | Apr-38 | | NRHS |
| 749 | MAWX | Mathieson Chemical Corp. | Jan-52 | | NRHS |
| 750 | MAWX | Olin Mathieson Chemical Corp. | 10/57-10/66; eliminated 1/70 | | NRHS |
| 751 | MAWX | Olin Corp. | added 1/70; 4/70; eliminated 4/73 | | NRHS |
| 752 | MAWX | *MICHIGAN AMMONIA WORKS | | | PWRC |
| 753 | MAWX | *OLIN CORP. [OLIN MATHIESON CHEMICAL CORP.; MATHIESON CHEMICAL CORP.; MATHIESON ALKALI WORKS] | | | PWRC |
| 754 | MAWX | OLIN MATHIESON CHEMICAL CORP | | | SCAC3 |
| 755 | MAX | Max Aviation Inc. | IATA: L4, Callsign: Max-Aviation, Designator L4* recalled by IATA | CDN | AVCODES |
| 756 | MAX | Max Aviation Inc. | Callsign: Max-Aviation, Designator L4* recalled by IATA | CDN | AVCODES |
| 757 | MAX | Max-Aviation | | | ICAO1 |
| 758 | MAX | Wyandotte Chemicals Corp., Michigan Alkali Div. | 1/1945-1/1946 | | NAKINA |
| 759 | MAX | Michigan Alkali Co. | 8/1920-1/1943 | | NAKINA |
| 760 | MAX | Michigan Alkali Co. | Apr-38 | | NRHS |
| 761 | MAX | WYANDOTTE CHEMICALS CORP., MICHIGAN ALKALI DIV. | | | PWRC |
| 762 | MAX | Max Schmid Transporte | City: Dietlikon | CH | TRAFFIC |
| 763 | MAX | MAVEX-REKORD Kft. | | HU | VKM |
| 764 | MAXE | MATROX ELECTRONIC SYSTEMS | | | SCAC4 |
| 765 | MAXF | MAX TRANSPORT & FREIGHT NETWORK INC | | | SCAC4 |
| 766 | MAXG | MAXAM NORTH EAST LLC | | | SCAC4 |
| 767 | MAXH | MID ATLANTIC XPRESS INC | | | SCAC4 |
| 768 | MAXH | Max Hütte | | D | TRAFFIC |
| 769 | MAXM | MAXIMU | | | SCAC4 |
| 770 | MAXN | MAXI CANADA INC | | | SCAC4 |
| 771 | MAXO | MAX PRODUCE | | | SCAC4 |
| 772 | MAXR | MAX TRUCKING INC | | | SCAC4 |
| 773 | MAXU | TEXTAINER EQUIPMENT MANAGEMENT LTD | | BM | BIC |
| 774 | MAXU | MAXU CONTAINERS LTD. | | | PWRC |
| 775 | MAXU | Maxu Containers | | | RSRV |
| 776 | MAXU | TEXTAINER EQUIPMENT MANAGEMENT BV | | | SCAC4 |
| 777 | MAXX | MidAmerican Energy Co. | added 4/1996; 7/2000-7/2005 | | NAKINA |
| 778 | MAXX | MidAmerican Energy Co. | added 4/96; 7/2000 | | NRHS |
| 779 | MAXX | MIDAMERICAN ENERGY COMPANY | | | PWRC |
| 780 | MAXX | MidAmerican Energy | | | RSRV |
| 781 | MAXX | Metropolitan Auckland XXpressways | | NZ | TRAFFIC |
| 782 | MAXY | MAXEY ENERGY COMPANY | | | SCAC4 |
| 783 | MAY | Maya Airways Ltd. | Callsign: Maya, | BH | AVCODES |
| 784 | MAY | Majestic Executive Aviation AG | | A | AVCODES |
| 785 | MAY | MAAT Ltd t/a Malta Air | IATA: AL, Callsign: Blue Med, Name changed to Malta Air Limited. Ryanair Holdings Group | M | AVCODES |
| 786 | MAY | Malta Air Limited | IATA: AL, Callsign: Blue Med, Name changed from MAAT Ltd t/a Malta Air. Ryanair Holdings Group | M | AVCODES |
| 787 | MAY | Malta Air Limited | Callsign: Blue Med, Designator AL recalled by IATA. Name changed from MAAT Ltd t/a Malta Air. Ryanair Holdings Group | M | AVCODES |
| 788 | MAYA | MAY TRUCKING COMPANY | | | SCAC4 |
| 789 | MAYB | MAYBEE, JOEL INC | | | SCAC4 |
| 790 | MAYC | MOYERS CHICKS INC | | | SCAC4 |
| 791 | MAYD | MAY TRUCKING COMPANY (DEDICATED SER | | | SCAC4 |
| 792 | MAYE | MAYE TRANSPORT INC | | | SCAC4 |
| 793 | MAYF | MAYS TRANSPORTS | | | SCAC4 |
| 794 | MAYG | MAY TRUCKING COMPANY (GEORGIA PACIF | | | SCAC4 |
| 795 | MAYI | MAYSHIP AGENCY LLC | | | SCAC4 |
| 796 | MAYJ | MAYA TRANSPORTATION COMPANY INC | | | SCAC4 |
| 797 | MAYK | MAYFAIR TRUCKING INC | | | SCAC4 |
| 798 | MAYL | MURPHY, RAYMOND TRUCKING LTD | | | SCAC4 |
| 799 | MAYM | MAYPA TRUCKING INC | | | SCAC4 |
| 800 | MAYN | MAYBERRY | | | SCAC4 |
