Vehicle registration plates of the Republic of Ireland Vehicle registration plates of the Republic of Ireland In the Republic of Ireland, vehicle registration plates (commonly known as "number plates") are the visual indications of motor vehicle registration – officially termed "index marks" – which it has been mandatory since 1903 to display on most motor vehicles used on public roads in Ireland. The alphanumeric marks (or "registration numbers") themselves were issued by the local authority in which a vehicle is first registered. The current specification for number plates is the format YYY–CC–SSSSSS. Those issued from 1987 to 2012 had the format YY–CC–SSSSSS. The components are: Since 1991, the
Vehicle registration plates of Portugal numbers indicate the start and end month of the vehicle's registration) and more similar to systems such as in Italy (where the date indicates the year of vehicle registration). Note that the date is that of first-ever registration of the vehicle, not the date the vehicle was registered in Portugal. Some vehicles carry plates that have a year and month seemingly out of tune with the alphanumeric sequence, and the reason for this is that these are imported used vehicles. Trailers and vehicles for export have the following district code letters in their licence plates: Until the 1970s only the