Home PPS Number Ireland
Ireland PPS Number validator
How the PPS Number format works
- Format
- 7 digits + 1 check letter + optional 2nd letter (A-I or W)
- Example
- 1234567T
Things to watch for
- The optional 9th character (A-I or W) marks the tax basis the number was issued under — it doesn't change whether the core 7-digit + check-letter combination is valid
- Format + mod-23 check-letter validation only — a pass doesn't confirm the PPSN is active with the Department of Social Protection
- Older PPS Numbers issued before 2013 typically carry just the single check letter, with no trailing second letter
^[0-9]{7}[A-W][A-IW]?$Ireland’s PPS Number (Personal Public Service Number) is the identifier the Department of Social Protection issues to everyone who deals with Irish tax, welfare, or public health services — employers, Revenue, and the HSE all key records to it. It’s 7 digits followed by a check letter, and sometimes a second trailing letter — for example 1234567T. That optional final letter (A through I, or W) simply marks the tax basis the number was issued under; it has no bearing on whether the core 7-digit-plus-check-letter combination is itself valid.
The check letter isn’t arbitrary — it comes from a weighted mod-23 calculation over the 7 digits (and the second letter, when present). Real-world Irish VAT numbers use broadly the same weighted-letter idea, while an Irish IBAN relies on a different scheme (the ISO 7064 mod-97 check digit). Either way, that built-in check is why a mistyped PPSN, unlike a plain sequential ID, gets caught by more than just a length check.
How this validator works
This tool checks that the input is 7 digits followed by a valid trailing letter (or two), then runs the real weighted mod-23 formula against the check letter — entirely in your browser, with nothing sent to a server and no signup required.
What a pass doesn’t tell you
A pass confirms the digits and check letter are mathematically consistent — not that the PPSN is currently active, or registered to you specifically, with the Department of Social Protection. Older PPS Numbers issued before 2013 typically carry only the single check letter with no second letter — both forms are equally valid if the mod-23 math checks out.
Scope: this page and tool cover PPSN format and mod-23 check-letter validation only — not confirming active registration with the Department of Social Protection or Revenue.
Content last reviewed 2026-07-22.
PPS Number FAQ
What does the optional second letter at the end of a PPS Number mean?
It marks the tax basis the number was issued under (A through I, or W) — administrative metadata, not part of the core check-letter calculation, so a PPSN with or without it can both be perfectly valid.
Is the PPSN check letter calculated the same way as Ireland's VAT number or IBAN?
It's a weighted mod-23 check letter — broadly the same approach real-world Irish VAT numbers use (a weighted digit sum mapped to a letter through a reference string), though each applies its own weights. It's a different scheme from an Irish IBAN, which uses an ISO 7064 mod-97 check digit instead.
Does a valid check letter confirm my PPSN is active with the Department of Social Protection?
No. It confirms the 7 digits and check letter are mathematically consistent — not that the number is currently active, assigned to you, or recognized by the Department of Social Protection or Revenue.