| 1 | CM | Compania Panamena de Aviacion, S.A. | Callsign: Compada, Name changed to COPA - Compania Panamena de Aviacion, S.A. | PA | AVCODES |
| 2 | CM | Compania Panamena de Aviacion, S.A. (COPA) | ICAO: CMP, Callsign: COPA, IATA Prefix: 230, Name changed from COPA - Airlines. Name changed from COPA - Compania Panamena de Aviacion, S.A. | PA | AVCODES |
| 3 | CM | Copa Airlines, Inc | ICAO: CMP, Callsign: COPA, IATA Prefix: 230, Name changed from Compania Panamena de Aviacion, S.A. (COPA) and previously from COPA - Airlines. Name changed from COPA - Compania Panamena de Aviacion, S.A. | PA | AVCODES |
| 4 | CM | PSI Air 2007, Inc. | ICAO: PHP, Callsign: Sky Power, IATA Prefix: 520, | RP | AVCODES |
| 5 | CM | Central Montana Rail, Inc. | added 7/1985; 1/1994-7/2005 | | NAKINA |
| 6 | CM | The Colorado Midland R.R. Co. (Midland Terminal Ry. Co.) | 8/1920-7/1923 | | NAKINA |
| 7 | CM | The Colorado Midland R.R. Co. (Midland Terminal Ry. Co.) | 23-Jul | | NRHS |
| 8 | CM | Central Montana Rail, Inc. | 1/94-7/2000 | | NRHS |
| 9 | CM | *MIDLAND TERMINAL RWY. CO. [COLORADO MIDLAND RAILROAD CO.] | | | PWRC |
| 10 | CM | +CENTRAL MONTANA RAIL, INC. | | | PWRC |
| 11 | CM | Central Montana Rail | | | RSRV |
| 12 | CM | CENTRAL MONTANA RAIL INC | | | SCAC4 |
| 13 | CM | Chemin de Fer de Chamonix au Montenvers | | FR | VKM |
| 14 | CM&G | Chicago, Milwaukee and Gary Ry. Co. (Chicago, Milwaukee, St. Paul & Pacific R.R. Co.) | 7/1930 | | NAKINA |
| 15 | CM&G | Chicago, Milwaukee and Gary Ry. Co. | 8/1920-7/1923 | | NAKINA |
| 16 | CM&G | Chicago, Milwaukee and Gary Ry. Co. | 23-Jul | | NRHS |
| 17 | CM&G | CHICAGO, MILWAUKEE, ST. PAUL & PACIFIC RR [CHICAGO, MILWAUKEE & GARY RWY.] | | | PWRC |
| 18 | CMA | Central European Airlines | Callsign: Eurocentral, | CZ | AVCODES |
| 19 | CMA | Nakorn Chiang Mai Airways | | T | AVCODES |
| 20 | CMA | CMA CGM Air Cargo S.A.S. | IATA: 2C, Callsign: French Cargo, IATA Prefix: 003, | F | AVCODES |
| 21 | CMA | Central European Airlines | | | ICAO1 |
| 22 | CMA | COLEMAN BUS SERVICE | | | SCAC4 |
| 23 | CMAA | C M A DELIVERY SERVICE | | | SCAC3 |
| 24 | CMAA | CMG TRANSPORT INC | | | SCAC4 |
| 25 | CMAB | CMAC EXPRESS INC | | | SCAC3 |
| 26 | CMAB | CAM INDUSTRIES CORP | | | SCAC4 |
| 27 | CMAC | COLEMAN AMERICAN MOVING SERVICES IN | | | SCAC3 |
| 28 | CMAC | COLEMAN AMERICAN MOVING SERVICES IN | | | SCAC4 |
| 29 | CMAD | CHAMBERLAIN MANUFACTURING CORPORATI | | | SCAC3 |
| 30 | CMAE | CAMERON, ARCHIE | | | SCAC3 |
| 31 | CMAE | CONSTRONIC MAE SA | | RO | VKM |
| 32 | CMAG | CANADA MARITIME AGENCIES LIMITED | | | SCAC3 |
| 33 | CMAG | CAMACHO TRUCKING | | | SCAC4 |
| 34 | CMAH | COMANCHE ROAD TRANSPORT LTD | | | SCAC3 |
| 35 | CMAI | COAST MACHINERY MOVERS, INC | | | SCAC3 |
| 36 | CMAI | CONCOURS MOLD ALABAMA INC | | | SCAC4 |
| 37 | CMAJ | C & M AUTO SALES | | | SCAC3 |
| 38 | CMAJ | CENTRAL MARKETING ASSOCIATES, INC | | | SCAC4 |
| 39 | CMAL | COMMERCIAL STEEL ERECTION INC | | | SCAC3 |
| 40 | CMAL | CMA SALES & LEASING INC | | | SCAC4 |
| 41 | CMAN | COLEMAN AMERICAN MOVING SERVICES IN | | | SCAC3 |
| 42 | CMAN | COLEMAN AMERICAN MOVING SERVICES IN | | | SCAC4 |
| 43 | CMAO | COMPLETE AUTO SALES INC | | | SCAC3 |
| 44 | CMAO | CACTUS MELON DIST INC | | | SCAC4 |
| 45 | CMAP | CAMSCO (A PARTNERSHIP) | | | SCAC3 |
| 46 | CMAP | CUSTOM LOGISTICS INC | | | SCAC4 |
| 47 | CMAQ | CM FARMS | | | SCAC4 |
| 48 | CMAS | COLLINGS MOVING & STORAGE | | | SCAC3 |
| 49 | CMAT | CONSTRUCTION MATERIALS TRANSPORT IN | | | SCAC3 |
| 50 | CMAU | CMA-CGM | | F | BIC |
| 51 | CMAU | CARGO MARINE CONTAINERS LTD | | | SCAC3 |
| 52 | CMAU | CMA-CGM | | | SCAC4 |
| 53 | CMAW | CABINET MASTER ARCHITECTURAL WOODWO | | | SCAC4 |
| 54 | CMAX | CALIFORNIA MANUFACTURERS ASSOCIATIO | | | SCAC3 |
| 55 | CMAX | CALIFORNIA MANUFACTURERS ASSOCIATIO | | | SCAC4 |
| 56 | CMAY | COLLINS AND MAY TRUCKING CO INC | | | SCAC3 |
| 57 | CMAY | C & M AIRWAYS INC | | | SCAC4 |
| 58 | CMAYL | Cape May-Lewes Ferry | | USA | TRAFFIC |
| 59 | CMAZ | CAPTAIN MINE ARCH OF ILLINOIS | | | PWRC |
| 60 | CMB | U.S. Transportation Command | Callsign: Camber, Operated by Civil owned Aircraft | USA | AVCODES |
| 61 | CMB | The Cumberland R.R. Co. | 7/1923 | | NAKINA |
| 62 | CMB | The Cumberland R.R. Co. | 23-Jul | | NRHS |
| 63 | CMB | *CUMBERLAND RAILROAD CO. | | | PWRC |
| 64 | CMB | *CADY MILLS BRANCH | | | PWRC |
| 65 | CMB | China Motor Bus | | HK | TRAFFIC |
| 66 | CMB | Compagnie du Mont Blanc | | FR | VKM |
| 67 | CMBB | CAMPBELL TRUCKING, INC | | | SCAC3 |
| 68 | CMBB | CAMPBELL TRUCKING INC | | | SCAC4 |
| 69 | CMBC | CHAMBLIN, FLOYD TRUCKING | | | SCAC3 |
| 70 | CMBC | CHAMBLIN, FLOYD TRUCKING | | | SCAC4 |
| 71 | CMBD | COMBINED TRANSPORT, INC. | | | SCAC3 |
| 72 | CMBD | COMBINED TRANSPORT INC | | | SCAC4 |
| 73 | CMBE | CAMPBELL, MIKE & ASSOCIATES LTD | | | SCAC4 |
| 74 | CMBF | CUMBEE FREIGHT SYSTEMS INC | | | SCAC3 |
| 75 | CMBF | C M GLOBAL LOGISTICS | | | SCAC4 |
| 76 | CMBG | CHABOT, MARIO | | | SCAC4 |
| 77 | CMBH | CHARTER MOBILE HOMES INC | | | SCAC3 |
| 78 | CMBI | ASSOCIATED TRANSPORT LINE | | | SCAC3 |
| 79 | CMBI | CAMPBELL, MARLIN | | | SCAC4 |
| 80 | CMBJ | CMR SERVICE CO | | | SCAC3 |
| 81 | CMBJ | CAMACHOS DE BAJA CALIFORNIA | | | SCAC4 |
| 82 | CMBK | CAMACHO BROKERS INC | | | SCAC3 |
| 83 | CMBK | CAMACH | | | SCAC4 |
| 84 | CMBL | CAMPBELL COMPANY OF IDAHO INC | | | SCAC3 |
| 85 | CMBL | City of Commerce Municipal Bus Lines | City: Commerce | US-CA | TRAFFIC |
| 86 | CMBM | C&M BUILDING MATERIALS, INC | | | SCAC3 |
| 87 | CMBO | COLUMBO TRANSPORTATION LINES | | | SCAC3 |
| 88 | CMBP | CAMPBELL, RON TRANSPORT INC | | | SCAC3 |
| 89 | CMBP | CAMBRIDGE PATTERNS LTD | | | SCAC4 |
| 90 | CMBQ | COLUMBIA MARITIME CORP | | | SCAC3 |
| 91 | CMBQ | CMD LOGISTICS CORP | | | SCAC4 |
| 92 | CMBR | COMBO MARITIME INC | | | SCAC4 |
| 93 | CMBT | CAMPBELL BETON TRANSPORT INC | | | SCAC4 |
| 94 | CMBU | CMB SA | | | PWRC |
| 95 | CMBU | CMB | | | RSRV |
| 96 | CMBU | COMPAGNIE MARITIME BELGE S.A. | | | SCAC3 |
| 97 | CMBU | SAFMARINE CONTAINER LINES NV | | | SCAC4 |
| 98 | CMBV | COLEMAN-MCLAIN BUS SERVICE | | | SCAC3 |
| 99 | CMBY | CENTRAL MASS BUS CO INC | | | SCAC3 |
| 100 | CMBY | CRIMSON EXPRESS INC | | | SCAC4 |
