In Ireland, vehicle registration plates (commonly known as "number plates" or "registration plates") are the visual indications of motor vehicle registration which has been mandatory since 1903 to display on most motor vehicles used on public roads in Ireland. The alphanumeric marks (or "registration numbers", officially termed "identification marks") themselves are issued by the local authority in which a vehicle is first registered. A vehicle's number plate is determined when it is first registered, the county/city code is taken from the first owner's postal address. Registration remains fixed on one vehicle until it is de-registered (exported, destroyed, etc.), and cannot be transferred to other vehicles.

Format

The current specification for number plates is the format YYH–CC–SSSSSS. Those issued from 1987 to 2012 had the format YY–CC–SSSSSS.

The components are: YY or YYH – a numeric year or half-year identifier based on date of the vehicle's first registration. The former YY format used the last two digits of the year the car was registered. The YYH format used since 2013 appends a 1 or 2 as a third digit depending on which half of the year the car was registered: 1 for January–June and 2 for July–December. CC – a one- or two-letter identifier of the area of the licensing authority, which registers vehicles on behalf of one or more local authorities. For example: D is the identifier for County Dublin (four local authorities: Dublin City Council, Dún Laoghaire–Rathdown County Council, Fingal County Council, South Dublin County Council) SO is the identifier for County Sligo (one local authority: Sligo County Council) SSSSSS – a one- to six-digit sequence number, starting with the first vehicle registered in the licensing authority area that year or half-year. For example, the 12,345th vehicle registered in Dublin in 1989 would display 89-D-12345; the 56,789th registered in Dublin in the first half of 2023 would display 231-D-56789.

Specifications

Since 1991, the design of the standard Irish number plate has been based on European standard guidelines, with a blue vertical band to the left of the plate containing the twelve stars of the Flag of Europe, below which is the country identifier for Ireland: IRL. The rest of the plate has a white background with black characters. There are usually two hyphens; between the year and county code, and between the county code and sequence number. Also required is the full Irish language name of the county/city which must be positioned above the identifier. From July 2025, new and existing vehicles emitting zero emissions at the tailpipe can optionally be registered with a green vertical band; rectangular plates have the green band printed to the right of the plate, while square plates feature the green band below the blue country identifier band.

The current regulations are set out in the Vehicle Registration and Taxation (Amendment) Regulations, 1999, as amended by the Vehicle Registration and Taxation (Amendment) Regulations 2012 and Vehicle Registration and Taxation (Amendment) Regulations 2025. These prescribe the format, dimensions and technical specifications of registration plates to be displayed on vehicles. They substitute the First Schedule of the Vehicle Registration and Taxation Regulations, 1992 to allow additional characters to be displayed on the registration plate and to ensure that these are displayed in the correct position and proportion. The changes were necessary to cater for increases in the number of car registrations.

A standard uniform character font is not required. The rules simply require legible black sans serif characters, no more than 70mm high and 36mm wide with a stroke width of 10mm, on a white reflective background. The result is that a large variety of perfectly legal font styles may be seen, on either pressed aluminium or acrylic plates, both of which are allowed. Commonly used fonts include a condensed version of Mandatory, Arial and FE-Schrift. Despite the rather relaxed lack of a specified font, the hyphen between the lettering must lie between the minimum dimensions of 13mm x 10mm or the maximum dimension of 22mm x 10mm.

If the plate's format does not meet the requirements, the vehicle will fail the mandatory periodic National Car Test (NCT), although some owners of custom plates evade this by switching to conformant plates temporarily for the NCT. As automatic number-plate recognition has become prevalent on toll roads and for traffic enforcement cameras, the use of hard-to-read nonstandard plates has become a concern. It is a criminal offence not to display plates in the specified format, liable to a fine after summary conviction of up to €5,000. In 2008, the Revenue Commissioners issued 69 formal warnings and launched no criminal prosecutions. The Road Traffic Act 2016 authorised the Garda Síochána (police) to issue a fixed-charge penalty instead of prosecution.Road Traffic Act 2016 §23 The power was extended to the Revenue Commissioners in 2023. However, the statutory instrument setting the applicable penalty (of €60) was not made until 2024,S.I. No. 227/2024 - Road Traffic Act 2010 (Part 3) (Fixed Charge Offences) Regulations 2024: Regulation 7 and Schedule 6, Part 2, Item 2 and the Garda mobile app connecting to its PULSE IT system was not updated until October 2025.

Current implementation

Sequence numbers may be reserved for new vehicle registrations only on completion of form VRT15A and payment of €1,000. Reserved vehicle registrations have some limitations:

This reservation was withdrawn from used imported vehicles on first Irish registration in 2015. Applications must be made on or after 1 November in the year before it is intended to first register the vehicle. The registration must be in the normal registration number format, meaning it must match the year, half year, county the vehicle will be registered in, and a sequence of digits. For example, 271-D-123456 is valid to be reserved for a Dublin resident intending to register a vehicle between January and July in 2027. The sequence number 1 of each year/half year is not available for reservation for vehicles registered in Cork, Dublin, Limerick, and Waterford. These are traditionally reserved for the respective mayor/lord mayor of these cities.

Notable examples of reserved registrations:

In 2019, Lord Mayor Paul McAuliffe, the Lord Mayor of Dublin, was entitled to receive the registration plate 191-D-1 on his official vehicle. Luxury cars with numeric names are often registered with a matching, usually pre-reserved sequence number: for example 06-D-911 on a Porsche 911 or 06-D-750 BMW 750 or 03-C-5 for a 2003 Citroen C5 and 08-D-89 for an Aston Martin DB9. Dublin radio station FM104 tend to register their vehicles with reserved number sequences ending with "104", e.g. 05-D-38104.

There are only two pre-1987 codes still issued in Ireland. "ZZ", administered by the AA Ireland as agents for the Revenue Commissioners, is given to registrants who are based outside the state and who only intend keeping the vehicle within Ireland for a period not exceeding one month. This form of temporary registration is usually used for vehicles that are purchased within Ireland but exported by its new owner to another sovereign state directly after purchase. The format of the code is ZZ followed by a five digit number. "ZV", which can be selected as an alternative to the current scheme when registering a vehicle older than 30 years for the first time in Ireland.

Special formats Imported used cars are registered based on the year of first registration in their country of original registration rather than the year of import. Early in this system, each county used to have a continuous sequence of numbers for vehicles so if a new car registered on 31 December 2010 was 10 D 37456, then the next registered car from 2010 registered in 2011 would be 10 D 37457. This changed in late 2011 when each county (prior to 2010) had their next available sequence number increased. For example, 10-D-120006 would be the 6th import in Dublin of a car from 2010, as Dublin's re-registration band starts at 120000. Meath's starts at 15000.

Vehicles registered to the Irish Defence Forces have plates with silver letters on black background. These do not feature the Irish-language county name.

Trade plates have plates with white letters on a dark green background, but with the reverse style of the normal plates: the trader's number for that year is displayed first, the county second, and the applicable year last.

Starting from 1st July 2025, electrically powered vehicles may have a (Pantone 7481 c) green stripe on the right side in standard single-line plates; in the two-lines type the green band is placed on the lower half of the blue euroband on the left.

Diplomatic plates are very similar to civilian format, except for the small "CD" between the index mark code and serial number. Code CD is not always shown in Diplomatic plates.

Index mark codes

The city codes are a single letter, the initial letter of its English-language name. Most county codes use the first and last letters of the county's name. For example, Sligo is SO. The exceptions to this are: Where the county shares its registration function with the city of the same name, in which case both use the single-letter code. An example of this is County Cork, which shares the same name with Cork City, and takes the code "C". Where a conflict exists, i.e. Kerry is KY, so Kilkenny is KK; and County Waterford was (until 2014) WD, (subsequently changed to "W"), so Wexford is WX. The "T" code which is used in County Tipperary. This is because the county was, until 2014, divided into Tipperary North Riding (TN) and Tipperary South Riding (TS). The codes are similar to the ISO 3166-2 codes for Irish counties. An exception is that the ISO code for Cork is IE-CO, since IE-C is used for the province of , and the ISO code for Tipperary is IE-TA (from the Irish name Tiobraid Árann).

Current index mark codes Code County Irish name Local authority C Cork Cork City Council Cork County Council CE Clare Clare County Council CN Cavan Cavan County Council CW Carlow Carlow County Council D Dublin Dublin City Council Dún Laoghaire–Rathdown County Council Fingal County Council South Dublin County Council DL Donegal Donegal County Council G Galway Galway City Council Galway County Council KE Kildare Kildare County Council KK Kilkenny Kilkenny County Council KY Kerry Kerry County Council L Limerick Limerick City and County Council LD Longford Longford County Council LH Louth Louth County Council LM Leitrim Leitrim County Council LS Laois Laois County Council MH Meath Meath County Council MN Monaghan Monaghan County Council MO Mayo Mayo County Council OY Offaly Offaly County Council RN Roscommon Roscommon County Council SO Sligo Sligo County Council T Tipperary Tipperary County Council W Waterford Waterford City and County Council WH Westmeath Westmeath County Council WX Wexford Wexford County Council WW Wicklow Wicklow County Council

Note: in the case of Counties Limerick, Tipperary, and Waterford, where a vehicle has been first brought into use in another country prior to 1 January 2014 and is subsequently imported into and registered in Ireland, the codes L, LK, TS, TN, W, and WD as formerly applicable continue to be issued for such vehicles. This is to maintain the integrity of the numbering system in place for the years prior to 2014.

Former index mark codes Codes used from 1987 to 2013: Code Local authority LK Limerick County Council TN North Tipperary County Council TS South Tipperary County Council WD Waterford County Council

EU standardised vehicle registration plates