| County | Car Registration letter(s) |
| Cork | |
| Clare | |
| Cavan | |
| Carlow | |
| Dublin | |
| Donegal | |
| Galway | |
| Kildare | |
| Kilkenny | |
| Kerry | |
| Limerick City | |
| Longford | |
| Louth | |
| Co. Limerick | |
| Leitrim | |
| | County | Car Registration letter(s) |
| Laois | |
| Meath | |
| Monaghan | |
| Mayo | |
| Offaly | |
| Roscommon | |
| Sligo | |
| Tipperary North | |
| Tipperary South | |
| Waterford City | |
| Co. Waterford | |
| Westmeath | |
| Wexford | |
| Wicklow | |
|