| Flag | Code | Country | Time Difference (GMT) | Group | Comment | Internet Code |
 | 853 | MACAU | 8 | | | mo |
 | 261 | MADAGASCAR (Republic of) | 3 | | | mg |
 | 351 | Madeira | 0 | POR | | pt |
 | 34 | Majorca | 1 | SPAIN | | es |
 | 265 | MALAWI | 2 | BCW | | mw |
 | 60 | MALAYSIA | 8 | BCW | | my |
 | 960 | MALDIVES (Republic of) | 5 | BCW | | mv |
 | 223 | MALI (Republic of) | 0 | | | ml |
 | 356 | MALTA | 1 | BCW, EU | | mt |
 | 876 | Maritime Mobile Service Applications | | GLOBAL | Reserved Code | |
| 877 | Maritime Mobile Service Applications | | GLOBAL | Reserved Code | |
 | 692 | MARSHALL ISLANDS (Republic of the) | 12 | | | mh |
 | 596 | MARTINIQUE (French Department of) | -4 | | | mq |
 | 222 | MAURITANIA (Islamic Republic of) | 0 | | | mr |
 | 230 | MAURITIUS (Republic of) | 4 | BCW | includes Rodriguez Island | mu |
 | 269 | MAYOTTE (Collectivite territoriale de la Republique francais) | 3 | | Country code shared with Comoros | yt |
 | 52 | MEXICO | -6 | | | mx |
 | 691 | MICRONESIA (Federated States of) | 11 | | | fm |
| 6998 | MIDWAY ISLAND | | | | |
| 34 | Minorca | 1 | SPAIN | | es |
| 875 | MOBIQ (MARITIME MOBILE SERVICE) | | GLOBAL | | |
 | 373 | MOLDOVA (Republic of) | 2 | | | md |
 | 377 | MONACO (Principality of) | 1 | | | mc |
 | 976 | MONGOLIA | 8 | | | mn |
 | 382 | MONTENEGRO | 1 | | Formally part of the Yugoslav Republic | |
 | 1664 | MONTSERRAT | -4 | BRD, LEE | | ms |
 | 212 | MOROCCO (Kingdom of) | 0 | | | ma |
 | 258 | MOZAMBIQUE (Republic of) | 2 | BCW | | mz |
 | 95 | MYANMAR (Union of) | 6.5 | | formally Burma | mm |
 | 389 | The Former Yugoslac Republic of MACEDONIA | 1 | EUC | | mk |