| 901 | MBCR | MANBECK, LARRY W | | | SCAC4 |
| 902 | MBCS | MONTREAL BEST CARRIER INC | | | SCAC4 |
| 903 | MBCV | MOORE, BENJAMIN & CO | | | SCAC4 |
| 904 | MBCW | MATHEWS BROTHERS COMPANY | | | SCAC4 |
| 905 | MBCX | Chicago Freight Car Leasing Co. | added 4/2007 | | NAKINA |
| 906 | MBCX | M.B.C.X. Leasing, LLC | added 7/1998; 7/2000; eliminated 4/2003; 7/2005 (not listed) | | NAKINA |
| 907 | MBCX | Material Brokerage Co. | added 10/1996; eliminated 7/1998 | | NAKINA |
| 908 | MBCX | The Mann Bros. Co. | 8/1920-7/1935 | | NAKINA |
| 909 | MBCX | Material Brokerage Co. | added 10/96; eliminated 7/98 | | NRHS |
| 910 | MBCX | M.B.C.X. Leasing, L.L.C. | added 7/98; 7/2000 | | NRHS |
| 911 | MBCX | *MANN BROS. CO. | | | PWRC |
| 912 | MBCX | +CHICAGO FREIGHT CAR LEASING CO. [M.B.C.X. LEASING, LLC; MATERIAL BROKERAGE COMPANY] | | | PWRC |
| 913 | MBCX | M.B.C.X. Leasing (Chicago Freight Car Leasing) | | | RSRV |
| 914 | MBCX | CHICAGO FREIGHT CAR LEASING CO | | | SCAC4 |
| 915 | MBCY | MOBSTER COMPANY LLC | | | SCAC4 |
| 916 | MBDC | MOBELL DISTRIBUTION CORPORATION | | | SCAC4 |
| 917 | MBDK | M B D TRUCKING LTD | | | SCAC4 |
| 918 | MBDL | MOBILEMED TRANSPORTATION SERVICES L | | | SCAC4 |
| 919 | MBDP | MBD TRANSPORT INC | | | SCAC4 |
| 920 | MBDT | MBD TRANSPORTATION INC | | | SCAC4 |
| 921 | MBDU | MULTIBOXX LIMITED | | HK | BIC |
| 922 | MBDY | MOORE, BUDDY TRUCKING INC | | | SCAC4 |
| 923 | MBE | Martin-Baker Ltd. | Callsign: Martin, | GB | AVCODES |
| 924 | MBE | Martin-Baker | | | ICAO1 |
| 925 | MBE | Müllheim-Badenweiler-Eisenbahn | | D | TRAFFIC |
| 926 | MBEC | MISS BECKYS SEAFOOD INC | | | SCAC4 |
| 927 | MBEG | MERBEN ENTERPRISES INC | | | SCAC4 |
| 928 | MBEN | MANDER BROS ENTERPRISES LTD | | | SCAC4 |
| 929 | MBEQ | MOBILE FORCE EQUIPMENT LLC | | | SCAC4 |
| 930 | MBER | ME! BATH EXPERIENCE INC | | | SCAC4 |
| 931 | MBES | MILLER, BILL EQUIPMENT SALES INC | | | SCAC4 |
| 932 | MBET | MCBEE TRUCKING INC | | | SCAC4 |
| 933 | MBF | Mabe Flights, S.L. | Callsign: Mabe Flights, | E | AVCODES |
| 934 | MBFA | MATA BARRADAS, FELIPE | | | SCAC4 |
| 935 | MBFC | MT BAKER FUEL COMPANY INC | | | SCAC4 |
| 936 | MBFI | MILLENNIUM BROKERAGE FIRM INC | | | SCAC4 |
| 937 | MBFS | MCDONALD OIL COMPANY | | | SCAC4 |
| 938 | MBFT | MB FUEL TRANSPORT INC | | | SCAC4 |
| 939 | MBFU | MBF CARPENTERS SHIPPING LTD | | MAL | BIC |
| 940 | MBFW | FENETRES MBF WINDOWS | | | SCAC4 |
| 941 | MBFX | MBF Industries, Inc. | added 7/1979; 1/1980; eliminated 7/1991 | | NAKINA |
| 942 | MBFX | MBF Industries, Inc. | added 7/79; 1/80; eliminated 7/91 | | NRHS |
| 943 | MBFX | RETIRED 08-13-91 ATP (1316) [MBF INDUSTRIES INC.] | | | PWRC |
| 944 | MBFX | MBF Industries | | | RSRV |
| 945 | MBFY | MILLER BROTHERS EXPRESS L C | | | SCAC4 |
| 946 | MBG | Zephyr Aviation Ltd | Callsign: Chalgrove, | GB | AVCODES |
| 947 | MBG | Muggenthaler Bau GmbH | | DE | VKM |
| 948 | MBGA | M L BROKERAGE INC | | | SCAC4 |
| 949 | MBGC | MCGAW, BRUCE GRAPHICS CANADA LTD | | | SCAC4 |
| 950 | MBGP | MARTIN BROKERAGE GROUP LLC | | | SCAC4 |
| 951 | MBGT | MAYBERRY GROUP INC, THE | | | SCAC4 |
| 952 | MBGU | MULTIBOXX LIMITED | | HK | BIC |
| 953 | MBGV | MEBS GLOBAL REACH LC | | | SCAC4 |
| 954 | MBHA | MAY-BRIDGE HARROWS | | | SCAC4 |
| 955 | MBHL | MAGIC BUS HAULING | | | SCAC4 |
| 956 | MBHR | MBH TRUCKS LLC | | | SCAC4 |
| 957 | MBHS | MEADOWBROOK HORSE TRANSPORTATION IN | | | SCAC4 |
| 958 | MBHT | M B H TRUCKING | | | SCAC4 |
| 959 | MBI | Mountian Bird, Inc. | Callsign: Mountain Bird, | USA | AVCODES |
| 960 | MBI | Mountain Bird | | | ICAO1 |
| 961 | MBI | Münzer Bioindustrie GmbH | | AT | VKM |
| 962 | MBIA | MICHIGAN BRAND INC | | | SCAC4 |
| 963 | MBIC | MITCHELL, BRAD INC | | | SCAC4 |
| 964 | MBID | MATADOR BROKERAGE INC | | | SCAC4 |
| 965 | MBIF | MORRAL BROS INC | | | SCAC4 |
| 966 | MBIG | MT BROKERAGE INC | | | SCAC4 |
| 967 | MBIH | MCTRUCK BROKERS INC | | | SCAC4 |
| 968 | MBII | MIERE BETAIL INC | | | SCAC4 |
| 969 | MBIL | MILLER, BILL TRUCKING | | | SCAC4 |
| 970 | MBIN | MCBAR INTERNATIONAL | | | SCAC4 |
| 971 | MBIQ | MORTON BUILDINGS INC | | | SCAC4 |
| 972 | MBIS | MBI TOURS | | | SCAC4 |
| 973 | MBIU | MORBRIDGE INTERNATIONAL LTD | | GB | BIC |
| 974 | MBIU | MORBRIDGE INTERNATIONAL LTD | | | SCAC4 |
| 975 | MBIX | Morse Bros., Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 976 | MBIX | Merchants Biscuit Co. | 7/1935 | | NAKINA |
| 977 | MBIX | Morse Bros., Inc. | Jul-00 | | NRHS |
| 978 | MBIX | MORSE BROTHERS, INC. | | | PWRC |
| 979 | MBIX | Morse Brothers | | | RSRV |
| 980 | MBIX | MORSE BROS INC | | | SCAC4 |
| 981 | MBJ | Tafarayt Jet | | MA | AVCODES |
| 982 | MBJ | Maribo - Bandholm Jernbane (Bandholmbanen) | 1869 - 1952 | DK | jernbanen.dk |
| 983 | MBJ | Malmö - Billesholm Järnväg | 1886 - 1896 | S | svenska-lok.se |
| 984 | MBJ | Maribo - Bandholm Jernbane (Bandholmbanen) | 1869 - 1952 | DK | TRAFFIC |
| 985 | MBJC | MAST BROTHERS CHOCOLATE | | | SCAC4 |
| 986 | MBJI | MACIAS BECERRA, JOSE ISABEL | | | SCAC4 |
| 987 | MBJR | M B J TRANSPORTATION | | | SCAC4 |
| 988 | MBJS | RODRIGUEZ TOSCANO, ARMANDO | | | SCAC4 |
| 989 | MBJU | RAFFLES LEASE PTE LTD | | SGP | BIC |
| 990 | MBK | Chrono Jet, Inc. | Callsign: Matblack, ICAO designator changed from BLK. ICAO Callsign changed from Blackmat. | CDN | AVCODES |
| 991 | MBKA | M & T BROKERAGE LLC | | | SCAC4 |
| 992 | MBKC | MOSLEYS TRUCK BROKERAGE INC | | | SCAC4 |
| 993 | MBKD | MEYER BROS TRUCKING | | | SCAC4 |
| 994 | MBKF | M S A BROKERAGE FIRM | | | SCAC4 |
| 995 | MBKG | MARTIN BROKERAGE INC | | | SCAC4 |
| 996 | MBKQ | MNC BROKERAGE INC | | | SCAC4 |
| 997 | MBKR | MIAMI TRADING AND BROKERS INC | | | SCAC4 |
| 998 | MBKS | MAMBRU | | | SCAC4 |
| 999 | MBKT | MARTIN TRANSPORT LOGISTICS LLC | | | SCAC4 |
| 1000 | MBKU | MITSUI & CO LTD | | | SCAC4 |
