Post-2013 format: YYH-CC-SSSSSS
Since 2013, Irish plates use a three-part format separated by hyphens:
| Part | Meaning | Example |
|---|---|---|
| YY | Two-digit year of registration | 26 = 2026 |
| H | Half-year: 1 = Jan–Jun, 2 = Jul–Dec | 1 = first half |
| CC | County code (1–2 letters) | D = Dublin |
| SSSSSS | Sequential number (1–6 digits) | 12345 |
Example: 261-D-12345 = Registered in the first half of 2026, Dublin, vehicle number 12,345.
Pre-2013 format: YY-CC-NNNN
Vehicles registered before 2013 use the older two-part format: year (2 digits), county code, and a four-digit sequential number. Example: 12-D-5678 = Registered in 2012, Dublin, vehicle 5,678.
Pre-2013 plates are still valid on the road and can be legally reproduced as replacement plates in the correct format.
Why did the format change in 2013?
The RSA introduced the half-year indicator (the 1 or 2 after the year) to better spread new car registrations across the year. Historically, new car sales were heavily concentrated in January. The new system created two registration periods — January (1) and July (2) — which helped even out demand and made Irish plate registrations easier to read at a glance.