| 7101 | MQOI | MCCULLOUGH SNAPPY SERVICE OIL CO IN | | | SCAC4 |
| 7102 | MQOJ | MORRIS, JACK OIL CO INC | | | SCAC4 |
| 7103 | MQOT | MORTRANS INC | | | SCAC4 |
| 7104 | MQPE | MARTIN PETROLEUM INC | | | SCAC4 |
| 7105 | MQPF | MCCOY, WM | | | SCAC4 |
| 7106 | MQPL | MIDWEST THREE (3) PL TRANSPORTATION | | | SCAC4 |
| 7107 | MQPX | Millennium Inorganic Chemicals, Inc. | added 7/2000; 7/2000-7/2005 | | NAKINA |
| 7108 | MQPX | Millennium Inorganic Chemicals, Inc. | added 7/2000; 7/2000 | | NRHS |
| 7109 | MQPX | MILLENNIUM INORGANIC CHEMICALS, INC. | | | PWRC |
| 7110 | MQPX | Millennium Inorganic Chemicals | | | RSRV |
| 7111 | MQPX | MILLENNIUM INORGANIC CHEMICALS INC | | | SCAC4 |
| 7112 | MQQC | MQ | | | SCAC4 |
| 7113 | MQRA | MAQUITRADE SA DE CV | | | SCAC4 |
| 7114 | MQRG | MORAN TRUCKING INC | | | SCAC4 |
| 7115 | MQRN | MILES RANCH | | | SCAC4 |
| 7116 | MQRP | M & R TRANSPORTATION SPECIALISTS LT | | | SCAC4 |
| 7117 | MQRT | MARATHON TRANSPORT | | | SCAC4 |
| 7118 | MQRX | Macquarie Rail Inc. | added 4/2008 | | NAKINA |
| 7119 | MQRX | MACQUARIE RAIL, INC. | | | PWRC |
| 7120 | MQRX | MACQUARIE RAIL INC | | | SCAC4 |
| 7121 | MQSA | MASSEY FUEL INC | | | SCAC4 |
| 7122 | MQSH | MOIRA SHIPPING COMPANY LIMITED | | | SCAC4 |
| 7123 | MQSI | MOLD SERVICES INTERNATIONAL INC | | | SCAC4 |
| 7124 | MQSP | MARQUARD | | | SCAC4 |
| 7125 | MQSY | MARI-TECH SYSTEMS | | | SCAC4 |
| 7126 | MQT | Air ITM S.A.S. | Callsign: Musketeer, | F | AVCODES |
| 7127 | MQT | Air ITM | | | ICAO1 |
| 7128 | MQT | Marquette Rail LLC | added 7/2006 | | NAKINA |
| 7129 | MQT | MARQUETTE RAIL LLC | | | PWRC |
| 7130 | MQT | Marquette Rail | | | RSRV |
| 7131 | MQT | MARQUETTE RAIL LLC | | | SCAC4 |
| 7132 | MQTB | MARQUISE TRANSPORTATION | | | SCAC4 |
| 7133 | MQTD | MCMULLEN TRANSPORTATION & DELIVERY | | | SCAC4 |
| 7134 | MQTE | MAC TEC S A DE C V | | | SCAC4 |
| 7135 | MQTG | M & T TRUCKING LLC | | | SCAC4 |
| 7136 | MQTK | MARQUIS, YVES TRUCKING | | | SCAC4 |
| 7137 | MQTL | MARLOW TRUCKING COMPANY INC | | | SCAC4 |
| 7138 | MQTN | M & T TRANSPORT | | | SCAC4 |
| 7139 | MQTO | MARINE TRANS LOGISTICS | | | SCAC4 |
| 7140 | MQTP | MATIC TRANSPORTATION INC | | | SCAC4 |
| 7141 | MQTQ | M & Q TRANSPORTATION INC | | | SCAC4 |
| 7142 | MQTR | MARROQUIN TRUCKS SERVICE SA DE CV | | | SCAC4 |
| 7143 | MQTT | MOROYOQUI TRANSPORT | | | SCAC4 |
| 7144 | MQUA | MACQUARRIE, JAMES R TRUCKING LTD | | | SCAC4 |
| 7145 | MQUE | MAC QUEEN ORCHARDS INC | | | SCAC4 |
| 7146 | MQUN | MARROQUIN AVILES, PEDRO | | | SCAC4 |
| 7147 | MQUO | MCQUISTON OIL | | | SCAC4 |
| 7148 | MQUP | MARCY EQUIPMENT | | | SCAC4 |
| 7149 | MQXT | MAXIMUS TRANSPORTATION INC | | | SCAC4 |
| 7150 | MQXU | MQLOGISTICS INC | | USA | BIC |
| 7151 | MQZT | MARQUEZ TRUCKING | | | SCAC4 |
| 7152 | MR | Air Mauritanie | ICAO: MRT, Callsign: Mike Romeo, IATA Prefix: 174, Designator MR reinsated by IATA. Founded in September 1962. Ceased operations during 2007. | RIM | AVCODES |
| 7153 | MR | Mongolian Airlines Group | ICAO: MML, Callsign: Trans Mongolia, IATA Prefix: 861, Name changed to Hunnu Air | MGL | AVCODES |
| 7154 | MR | McCloud Ry. Co. | added 7/1992; 1/1994-7/2005 | | NAKINA |
| 7155 | MR | McCloud River R.R. Co. | 8/1920-1/1980; eliminated 7/1992 | | NAKINA |
| 7156 | MR | McCloud River R.R. Co. | 4/38-1/80; eliminated 7/92 | | NRHS |
| 7157 | MR | McCloud Ry. Co. | added 7/92; 1/94-7/2000 | | NRHS |
| 7158 | MR | *MAINE RAIL | | | PWRC |
| 7159 | MR | +(MCR) MCCLOUD RAILWAY COMPANY [MCCLOUD RIVER RAILWAY] | | | PWRC |
| 7160 | MR | McCloud River Railroad (McLeod Railway) | | | RSRV |
| 7161 | MR | Mission Railroad Spec. | | | TRAFFIC |
| 7162 | MR | Metroferro Roma (\"Met.Ro.\") | | IT | VKM |
| 7163 | MRA | Martinaire | Callsign: Martex, ICAO callsign changed from Martinaire U S | USA | AVCODES |
| 7164 | MRA | Martinaire | | | ICAO1 |
| 7165 | MRAA | MARTINEZ RODRIGUEZ, AARON | | | SCAC4 |
| 7166 | MRAC | MOORE & SON CO | | | SCAC1 |
| 7167 | MRAD | MCRAE, F D TRUCKING INC | | | SCAC4 |
| 7168 | MRAE | McRAE, BILL, TRUCKING | | | SCAC1 |
| 7169 | MRAE | MATHESON, ROY AND ASSOCIATES INC | | | SCAC4 |
| 7170 | MRAF | MORGAN, D W | | | SCAC4 |
| 7171 | MRAG | MARQUEZ RODRIGUEZ, ROBERT | | | SCAC4 |
| 7172 | MRAP | J. A. MIARA TRANS INC. | | | SCAC1 |
| 7173 | MRAP | MIARA, J A TRANSPORTATION INC | | | SCAC4 |
| 7174 | MRAT | MAR & ALI TRANSFER | | | SCAC4 |
| 7175 | MRAV | MORELAND OIL CO | | | SCAC4 |
| 7176 | MRAW | MARS TRANSPORTATION INC | | | SCAC4 |
| 7177 | MRAX | Mineral Range, Inc. | 7/2000-7/2005 (not listed) | | NAKINA |
| 7178 | MRAX | Mineral Range, Inc. | Jul-00 | | NRHS |
| 7179 | MRAX | MINERAL RANGE, INC. | | | PWRC |
| 7180 | MRAX | Mineral Range | | | RSRV |
| 7181 | MRAX | MINERAL RANGE INC | | | SCAC4 |
| 7182 | MRAY | MICHAUD & RAYMOND OIL INC | | | SCAC4 |
| 7183 | MRB | Centre Pankh Kazakhstan | Callsign: Toma, | KZ | AVCODES |
| 7184 | MRB | Mitteldeutsche Regiobahn | Leipzig (Veolia-Verkehr Regio Ost) | D | privat-bahn.de |
| 7185 | MRB | Mitteldeutsche Regiobahn | | D | TRAFFIC |
| 7186 | MRBC | M & R TRUCK BROKERS | | | SCAC4 |
| 7187 | MRBD | MURRAY, D B LTD | | | SCAC4 |
| 7188 | MRBE | MIRABELLI, P J ENTERPRISES INC | | | SCAC4 |
| 7189 | MRBH | MCEVE | | | SCAC4 |
| 7190 | MRBJ | MOST RELIABLE COURIER INC | | | SCAC4 |
| 7191 | MRBL | M & R TRANSPORTATION LLC | | | SCAC4 |
| 7192 | MRBM | M & R TRUCKING | | | SCAC4 |
| 7193 | MRBN | MORENO BENITEZ, EDIEL | | | SCAC4 |
| 7194 | MRBO | MRB TRANSPORT INC | | | SCAC4 |
| 7195 | MRBQ | M C & S TRANSPORT LTD | | | SCAC4 |
| 7196 | MRBR | MR BROTHERS INC | | | SCAC4 |
| 7197 | MRBT | MIRABITO, JAMES & SONS | | | SCAC4 |
| 7198 | MRBU | GERMAN AEROSPACE CENTER | | D | BIC |
| 7199 | MRBU | DEUTSCHES ZENTRUM FUR LUFT UND RAUM | | | SCAC4 |
| 7200 | MRBV | MACLEANS READY MIX CONCRETE LTD | | | SCAC4 |
