| 1 | MH | Malaysia Airlines System Berhad | ICAO: MAS, Callsign: Malaysian, IATA Prefix: 232, Name changed to Malaysia Airlines Berhad. Name changed from Malaysian Airlines Berhad (MAL) | MAL | AVCODES |
| 2 | MH | Malaysia Airlines Berhad (MAL) | Callsign: Malaysia, IATA Prefix: 232, Name changed to Malaysian Airline System Berhad | MAL | AVCODES |
| 3 | MH | Malaysia Airlines Berhad d/b/a Malaysia Airlines | ICAO: MAS, Callsign: Malaysian, IATA Prefix: 232, Name changed from Malaysia Airlines System Berhad. Name changed from Malaysian Airlines Berhad (MAL) | MAL | AVCODES |
| 4 | MH | Mount Hood R.R. Co. | 7/2000-7/2005 | | NAKINA |
| 5 | MH | Mount Hood R.R. | added 1/1989; eliminated 10/1989 | | NAKINA |
| 6 | MH | Mount Hood Ry. Co. | 1/1975-1/1980; eliminated 1/1989 | | NAKINA |
| 7 | MH | Mount Hood Ry. Co. | 1/75-1/80; eliminated 1/89 | | NRHS |
| 8 | MH | Mount Hood R.R. | added 1/89; eliminated 10/89 | | NRHS |
| 9 | MH | Mount Hood R.R. Co. | Jul-00 | | NRHS |
| 10 | MH | MT. HOOD RAILROAD COMPANY | | | PWRC |
| 11 | MH | Mount Hood Railroad | | | RSRV |
| 12 | MH | MT HOOD RAILROAD CO | | | SCAC4 |
| 13 | MH | Mohawk & Hudson | | USA | TRAFFIC |
| 14 | MH | Museumseisenbahn Hanau e.V. | | DE | VKM |
| 15 | MH&W | Hill City Ry. Co. | 8/1920 | | NAKINA |
| 16 | MH&W | HILL CITY RWY. CO. | | | PWRC |
| 17 | MHA | Mountain High Aviation | Callsign: Mountain High, | USA | AVCODES |
| 18 | MHA | Anglian Air Taxis | Callsign: Anglian, | GB | AVCODES |
| 19 | MHA | Mountain High Aviation | | | ICAO1 |
| 20 | MHAA | M-TECH | | | SCAC4 |
| 21 | MHAC | METAL FAB PRO RACE SHOP | | | SCAC4 |
| 22 | MHAE | MICHAEL, GEORGE | | | SCAC4 |
| 23 | MHAH | MACRAY HARBOR | | | SCAC4 |
| 24 | MHAI | MEEHAN TRANSPORT LLC | | | SCAC4 |
| 25 | MHAK | MOHAWK TRANSPORTATION INC | | | SCAC4 |
| 26 | MHAN | MEEHA | | | SCAC4 |
| 27 | MHAR | MARSHA | | | SCAC4 |
| 28 | MHAT | MEDICINE HAT EXPRESS INC | | | SCAC4 |
| 29 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | 7/2000-7/2005 (not listed) | | NAKINA |
| 30 | MHAX | U.S. Dept. of the Interior, Bureau of Land Management, Helium Operations | eliminated 10/1998 | | NAKINA |
| 31 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | added 7/1982; 1/1994 | | NAKINA |
| 32 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Division of Helium Operations, Amarillo, Texas | added 10/1981; eliminated 7/1982 | | NAKINA |
| 33 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | added 7/1980; eliminated 10/1981 | | NAKINA |
| 34 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Operations, Amarillo, Texas | eliminated 7/1980 | | NAKINA |
| 35 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Operations | added 7/1971; 1/1975-1/1980 | | NAKINA |
| 36 | MHAX | U.S. Dept. of the Interior, Bureau of Mines Helium Activity | 10/1966; eliminated 7/1971 | | NAKINA |
| 37 | MHAX | U.S. Dept. of the Interior, Bureau of Mines | 10/1957-7/1965 | | NAKINA |
| 38 | MHAX | U.S. Dept. of the Interior, Bureau of Mines Helium Activity | added 7/1955 | | NAKINA |
| 39 | MHAX | U.S. Dept. of the Interior, Bureau of Mines Helium Activity | added 7/55 | | NRHS |
| 40 | MHAX | U.S. Dept. of the Interior, Bureau of Mines | 10/57-7/65 | | NRHS |
| 41 | MHAX | U.S. Dept. of the Interior, Bureau of Mines Helium Activity | Oct-66 | | NRHS |
| 42 | MHAX | U.S. Dept. of the Interior, Bureau of Mines | Apr-70 | | NRHS |
| 43 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Operations | 1/75-1/80 | | NRHS |
| 44 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Operations, Amarillo, Texas | eliminated 7/80 | | NRHS |
| 45 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | added 7/80; eliminated 10/81 | | NRHS |
| 46 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Division of Helium Operations, Amarillo, Texas | added 10/81; eliminated 7/82 | | NRHS |
| 47 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | added 7/82; 1/94 | | NRHS |
| 48 | MHAX | U.S. Dept. of the Interior, Bureau of Land Management, Helium Opers | eliminated 10/98 | | NRHS |
| 49 | MHAX | U.S. Dept. of the Interior, Bureau of Mines, Helium Field Operations, Amarillo, Texas | Jul-00 | | NRHS |
| 50 | MHAX | US DEPT. OF THE INTERIOR - BUREAU OF MINES, HELIUM FIELD OPERATIONS, AMARILLO, TX | | | PWRC |
| 51 | MHAX | United States Department of the Interior Bureau of Mines Helium Field Operations | | | RSRV |
| 52 | MHAX | USDI-BUR OF MINES,DIV OF HELIUM OPE | | | SCAC4 |
| 53 | MHAY | MEHERRIN AGRICULTURAL & CHEMICAL CO | | | SCAC4 |
| 54 | MHBR | MCHUGH BROTHERS | | | PWRC |
| 55 | MHBU | BATIMPEX | | | SCAC4 |
| 56 | MHBW | MAESTRO SHIPPING BV | | | SCAC4 |
| 57 | MHC | Aero Jomacha, S.A. de C.V. | Callsign: Aero Jomacha, | MEX | AVCODES |
| 58 | MHC | Aero Jomacha | | | ICAO1 |
| 59 | MHC | MOHALL CENTRAL RAILROAD, INC. | | | PWRC |
| 60 | MHC | MOHALL CENTRAL RAILROAD INC | | | SCAC4 |
| 61 | MHCA | MICHAEL, CHRISTOPHER & ASSOCIATES I | | | SCAC4 |
| 62 | MHCC | MALHA TRANSPORT INC | | | SCAC4 |
| 63 | MHCD | MATTHES, C. D., INC. | | | SCAC1 |
| 64 | MHCE | MACHINE CARRIERS | | | SCAC4 |
| 65 | MHCG | MACKENZIE HEATING AND COOLING INC | | | SCAC4 |
| 66 | MHCH | MID-SOUTH CONSOLIDATED CHASSIS POOL | | | SCAC4 |
| 67 | MHCI | MOUNTAIN HIGH CONTRACTORS INC | | | SCAC4 |
| 68 | MHCK | MOHAWK CUSTOMS AND SHIPPING CO INC | | | SCAC4 |
| 69 | MHCM | M H C MESSENGERS INC | | | SCAC4 |
| 70 | MHCN | MILLER HONEY CO INC | | | SCAC4 |
| 71 | MHCO | Marquette & Huron Mountain R.R. Co., Inc. | 1/1975-1/1980 | | NAKINA |
| 72 | MHCO | Marquette & Huron Mountain R.R. Co., Inc. | 1/75-1/80 | | NRHS |
| 73 | MHCO | MARQUETTE & HURON MOUNTAIN RAILROAD CO. | | | PWRC |
| 74 | MHCO | Marquette and Huron Mountain Railroad | | | RSRV |
| 75 | MHCP | MCH TRANSPORTATION CO | | | SCAC4 |
| 76 | MHCQ | MARSHALL CONSTRUCTION CO INC | | | SCAC4 |
| 77 | MHCR | M H CRUCES INTERNACIONALES | | | SCAC4 |
| 78 | MHCT | MITSUBISHI CORPORATION | | | SCAC4 |
| 79 | MHCU | MAG CONTAINER LINES INC | | SY | BIC |
| 80 | MHCU | MINTURNO CORPORATION | | | SCAC4 |
| 81 | MHD | Yas Air Kish | Callsign: Yas Air, | IR | AVCODES |
| 82 | MHDBB | | City: Banska Bystrica | SK | TRAFFIC |
| 83 | MHDE | MUSH DELIVERY | | | SCAC4 |
| 84 | MHDM | MONTS ON-TIME EXPRESS INC | | | SCAC4 |
| 85 | MHDN | MAHDI & SON TRANSPORT INC | | | SCAC4 |
| 86 | MHDS | MARCHAND, DENIS TRANSPORT | | | SCAC4 |
| 87 | MHDT | MUIRHEAD TRUCKING INC | | | SCAC4 |
| 88 | MHDU | MISUBISHI HEAVY INDUSTRIES LTD. | | | SCAC4 |
| 89 | MHDV | MYHRE, DAVID INC | | | SCAC4 |
| 90 | MHE | Meppen-Haselünner Eisenbahn | | D | TRAFFIC |
| 91 | MHEH | MOUNTAIN HIGH EXPRESS | | | SCAC4 |
| 92 | MHEI | MEREDITH ENTERPRISES INC | | | SCAC4 |
| 93 | MHEL | M & H EXPRESS LINE LLC | | | SCAC4 |
| 94 | MHEP | MARIAH EXPRESS INC | | | SCAC4 |
| 95 | MHEQ | M & H EXPRESS INC | | | SCAC4 |
| 96 | MHES | MALHI EXPRESS | | | SCAC4 |
| 97 | MHEV | MASTER HAUL ENTERPRISES INC | | | SCAC4 |
| 98 | MHF | Maritime Helicopters | Callsign: Air Maritime, | USA | AVCODES |
| 99 | MHFD | MOHAWK FLUSH DOORS INC | | | SCAC4 |
| 100 | MHFF | MILE HI FROZEN FOODS CO | | | SCAC1 |
