| Code | Name | Region |
|---|---|---|
| IEMGL | Mogeely | CO |
| IEMON | Monaghan | |
| IEMBE | Monasterboice | LH |
| IEMNV | Monesterevin | KE |
| IEMOT | Moneypoint | |
| IEMBW | Mount Bellew | G |
| IEMOU | Mountmellick | LS |
| IEMTH | Mountrath | LS |
| IEMOV | Moville | DL |
| IEMOB | Moy Bridge | |
| IEMOY | Moycullen | G |
| IEMLT | Mulhurddart | D |
| IEMLA | Mullagh | CN |
| IEMUG | Mullagh | MH |
| IEMLL | Mulligan | |
| IELIC | Little Island/cork | |
| IELGA | Loch Gowna | CN |
| IELON | Longford | |
| IELEH | Lough Egish | MN |
| IELOG | Loughlinstown | D |
| IELOU | Loughrea | |
| IELTH | Louth | |
| IELKY | Lucan | D |
| IELAR | Lurganm Armagh | CW |
| IEMCR | Macroom | |
| IEMAG | Maghera | |
| IEMRT | Magheraroarty | DL |
| IEMAH | Malahide | D |
| IEMAL | Mallow | |
| IEMHN | Manorhamilton | LM |
| IEMAP | Marino Point | |
| IEMAR | Marshmeadows/new Ross | WX |
| IEMAY | Maynooth | |
| IEMYO | Mayo | MO |
| IEMID | Midleton | |
| IEKTE | Kilteel | KE |
| IEKTA | Kilternan | D |
| IEKWH | Kilworth | CO |
| IEKCT | Kingscourt | |
| IEKNG | Kinnegad | WH |
| IEKLN | Kinsale | |
| IEKSL | Kinsealy | D |
| IEKIA | Kinvarra | G |
| IENOC | Knock | |
| IENOK | Knockalough | CE |
| IEKTH | Knocktopher | KK |
| IELBH | Lanesborough | LD |
| IELEI | Leitrim | |
| IELEX | Leixlip | |
| IELTR | Letterkenny |