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Finland HETU Validator

Online validator for Finnish Henkilötunnus (HETU) personal identity code with Modulo 31 check.

About the Henkilötunnus (HETU)

Finnish Personal Identity Code used across Finland.

This validator ensures date correctness and algorithm conformity.

Finnish HETU Anatomy & Structure

The Henkilötunnus follows the strict format DDMMYYCZZZQ (11 characters):

PositionFieldLengthRule & MeaningExample
1 to 6Date of Birth6 digitsDDMMYY format010101
7Century Sign1 char"+ " (1800s), "-" (1900s), or "A" (2000s)-
8 to 10Individual Number3 digits002 to 899 (odd for male, even for female)031
11Check Character1 charLookup in 31-character table (0-9, A-Y)P

Official Algorithm (DVV Modulo 31)

Digital and Population Data Services Agency (DVV) check calculation:

Index = (DDMMYYZZZ) mod 31; Char = TABLE[Index]; TABLE = "0123456789ABCDEFHJKLMNPRSTUVWXY".
  1. 1. Combine date and individual digits.
  2. 2. Compute remainder modulo 31.
  3. 3. Retrieve character from DVV table.
  4. 4. Verify match against the 11th character.

Frequently Asked Questions (FAQ)