Irish number plate decoder.

How an Irish registration number is built

Revenue issues Irish vehicle registration numbers when a vehicle is registered at a National Car Testing Service centre, and it publishes the format rules on its Vehicle Registration Tax pages. Since 1 January 2013 the format is YY1 or YY2, then the county, then a sequence number, as in 191-D-12345. Before that the format was year, county, sequence, with no half-year digit, as in 08-KY-1234. This decoder splits a registration into those parts and looks the county mark up in the Revenue tables. It tells you the registration year, which half of the year the number belongs to, and the registration district.

County index marks, before and after 2014

The county marks changed on 1 January 2014. Revenue's Registration Districts table, which cites Statutory Instrument 452 of 2013 (the Vehicle Registration (Identification Marks) Regulations 2013), gives one list of marks for vehicles first registered on or before 31 December 2013 and a shorter list for vehicles first registered anywhere on or after 1 January 2014. Limerick used L and LK, Tipperary used TN and TS, and Waterford used W and WD in the older list. The newer list has one mark for each: L, T and W. The decoder checks the mark against the correct list for the registration year, so a 2016 plate with LK is rejected and a 2012 plate with T is rejected too.

Worked example

These registrations are made up for illustration.

The first row shows how the half-year digit works: the 1 in 191 does not make the year 1919 or the vehicle's 191st registration, it just places the number in January to June 2019.

Edge cases and common mistakes

• Imports. Revenue says the format applies to vehicles registered either in Ireland or another country. Its example is a car imported in 2017 that was first registered in the UK in 2011: it is registered as 11-xx-xxxx. The year on the plate is the first registration anywhere, not the year the vehicle arrived.
• Bare years from 2013 on. A plate such as 15-D-123 has no half-year digit but a year of 2015, which does not fit the post-2013 format, so the tool flags it.
• Reading the 1 or 2 as part of the year. In 132-C-45 the year is 13 and the 2 means July to December 2013, not 132.
• Reserved numbers. Revenue lets you reserve a number for €1,000 from 1 November in the year before first registration. The number and county must fit the year and half-year, and the county must correspond with where the applicant normally resides. Revenue also says all numbers can be reserved except number 1 in Cork, Dublin, Limerick and Waterford.
• Green flash plates. Since 1 July 2025 vehicles that do not emit CO2 tailpipe emissions can have a plate with a green stripe. The plate otherwise looks the same, so the stripe does not change how the number reads.

Who this is for

Used-car buyers comparing a plate with an advert, people importing a vehicle who want to know what year and county mark will go on it, fleet and insurance admins checking registration entries, and anyone curious why one Irish plate says 241 and another 242.

What this does not cover

The decoder does not look up the vehicle, owner, tax, NCT status or history, and it cannot tell you whether a number has been issued. It does not cover ZZ registrations, vintage ZV plates, Northern Ireland plates or foreign plates. A fine of up to €5,000 applies to displaying plates that do not meet Revenue's legal format and size standards, so a plate maker or the Revenue page is the place to confirm layout, not this tool.

Sources

• Revenue: Registration plates and format standards
• Revenue: Registration Districts (county index marks, update from 1 January 2014)

Retrieved 20 October 2026. Issuing bodies can change these rules; check the source if a result matters.

FAQ

What does 191-D-12345 mean on an Irish number plate?

19 is the year (2019), the 1 means the vehicle was registered between 1 January and 30 June, D is the county index mark for Dublin and 12345 is the sequence number.

What is the 1 or 2 after the year on an Irish plate?

Revenue says that for vehicles registered since 1 January 2013 the year is broken into two halves: YY1 applies from 1 January to 30 June and YY2 applies from 1 July to 31 December.

What was the Irish plate format before 2013?

Year, county, sequential number, for example 08-KY-1234, with no half-year digit. Revenue says this format applies to vehicles registered before 2013, whether registered in Ireland or another country.

Which Irish county marks changed in 2014?

Revenue’s tables change Limerick from L or LK to L, Tipperary from TN or TS to T, and Waterford from W or WD to W for vehicles first registered on or after 1 January 2014. The change comes from Statutory Instrument 452 of 2013.

Does the county on an Irish plate show where the owner lives?

It names the registration district. Revenue says a reserved number must correspond with the place where the applicant normally resides.

What year does an imported car get on an Irish plate?

The year the vehicle was first registered anywhere. Revenue’s example is a car imported in 2017 that was first registered in the UK in 2011, which receives a 11-xx-xxxx registration.

Can I reserve a particular Irish registration number?

Yes. Revenue charges €1,000 and accepts applications from 1 November in the year before first registration. The number must fit the year, half-year and county. Number 1 is not available in Cork, Dublin, Limerick or Waterford.

Do electric cars have a different Irish plate format?

No. Since 1 July 2025 vehicles with no tailpipe CO2 emissions can have a plate with a green stripe, but Revenue says the plates look the same otherwise and the number format is unchanged.