Home henkilötunnus (HETU) Finland
Finland henkilötunnus (HETU) validator
How the henkilötunnus (HETU) format works
- Format
- 11 characters (DDMMYY + century sign + 3-digit individual number + check character)
- Example
- 131052-308T
Things to watch for
- 11 characters: DDMMYY, a century sign (+ for the 1800s, one of -/Y/X/W/V/U for the 1900s, A–F for the 2000s), a 3-digit individual number, and a check character
- The check character is the 9-digit DDMMYY + individual-number value taken mod 31 and mapped through a 31-character alphabet
- Checksum only — validation runs entirely in your browser and nothing you enter is stored; a passing check doesn't confirm the number is currently issued by the Digital and Population Data Services Agency
^[0-9]{6}[+\-YXWVUABCDEF][0-9]{3}[0-9A-Y]$A henkilötunnus (HETU), sometimes called a personal identity code, is Finland’s 11-character identifier, issued by the Digital and Population Data Services Agency (DVV) to residents and used for tax records, banking, healthcare, and most official paperwork in the country. Unlike a purely numeric national ID, a HETU mixes digits and letters: DDMMYY for the birth date, a single century-sign character, a 3-digit individual number, and a final check character.
That century sign is what sets the format apart from many other countries’ date-based ID numbers: rather than leaving the century ambiguous or requiring a second formula to guess it, Finland encodes it directly as one character — a plus sign (+) for the 1800s, one of -, Y, X, W, V, or U for the 1900s, or a letter A through F for the 2000s. The final check character is calculated by combining the birth-date digits and individual number into a 9-digit value, reducing it modulo 31, and mapping the result through a fixed 31-character alphabet.
How this validator works
This tool confirms the 11-character pattern — 6 digits, a valid century sign, 3 digits, and a check character — then recomputes the mod-31 value from the digits and compares it to the check character supplied. It runs entirely in your browser; nothing you enter is transmitted or stored.
What a pass doesn’t tell you
A matching check character confirms the 11 characters are internally consistent — not that this HETU was ever issued or is currently active. Only the Digital and Population Data Services Agency can confirm a specific HETU is genuinely on file.
Scope: this page covers HETU format and mod-31 check-character validation only — not identity or registration verification. Because the code encodes a date of birth, treat a pass as a typo-check, not as proof of anything about the person behind it.
Content last reviewed 2026-07-23.
henkilötunnus (HETU) FAQ
What does the century sign in the middle of a HETU mean?
It's a single character that removes the two-digit-year ambiguity other countries' date-based ID numbers have to work around: a plus sign (+) means the birth year is in the 1800s, one of -, Y, X, W, V, or U means the 1900s, and a letter from A to F means the 2000s. The hyphen (-) is the sign most commonly seen, covering most people born in the 20th century.
How is the final check character calculated?
The 6 birth-date digits and the 3-digit individual number are combined into a single 9-digit value, that value is reduced modulo 31, and the remainder is mapped through a fixed 31-character alphabet of digits and uppercase letters — with a handful of letters left out to avoid visual confusion with digits or other letters — to produce the check character.
Is a HETU purely numeric like most other national ID numbers?
No — a HETU is 11 characters, not 11 digits. Both the century sign and the final check character can be letters, so this isn't a checksum you can run with plain digit arithmetic alone.