henkilötunnus

The henkilötunnus identifies you across every Finnish system at once. Tax, health care, banking, employment and benefits all key off the same eleven characters.

It reads DDMMYY, then a character for the century, then a three-digit individual number, then a check character. So 010190-123M is someone born on the first of January 1990, and the M at the end is calculated from the other nine digits.

The individual number does more than count people. Odd numbers are issued to men and even numbers to women, so anyone who has ever seen your hetu has read your date of birth and your registered sex off it without being told either.

Finland has been trying to change that since 2020 and has not managed it yet. A working group proposed dropping the sex link from codes issued from 2027; the bill reached Parliament in February 2023 and lapsed without passing. The parity is still there today, and the plan is now waiting on a government willing to pick it up again.

The last character is a checksum. Take the nine digits as a number, divide by 31, and the remainder picks a character out of a fixed set of thirty-one: 0123456789ABCDEFHJKLMNPRSTUVWXY. G, I, O, Q and Z are missing on purpose, because in handwriting they get read as digits.

1. 1

   Them Sanoisitko henkilötunnuksen?

   Could you give me your identity code?

2. 2

   You Nolla yks nolla yks yheksänkyt, viiva, yks kaks kolme M.

   010190-123M, read out digit by digit.

   Digits singly for the day and month, the year as a number, then the letter.

3. 3

   Them Kiitos. Hetkinen.

   Thanks. One moment.

4. 4

   You Joo.

   Sure.

   The whole thing takes fifteen seconds and needs no small talk around it.

Constantly, and out loud. Reading your hetu across a pharmacy counter is completely routine and nobody lowers their voice to do it.

Hetu is what people say. Henkilötunnus is what the form prints. Sotu is the older word and you will still hear it, mostly from older speakers.

The three-digit individual number is not a serial for the whole population, only for people born on that exact date, and it runs from 002 to 899. The 900s are reserved for temporary codes issued when an identity has not been confirmed.

That produced a problem few people outside the registry saw coming. Popular birth dates were heading for exhaustion, so from 1 January 2023 the century character was expanded: the 1900s can now be a hyphen or Y, X, W, V or U, and the 2000s can be A through F. The agency issued the first code with a Y on 19 December 2023, days after running out of codes for the single most common birth date.

That change has a practical edge for anyone building systems. The separator is now part of what makes a code unique, so two different people can share a birth date and an individual number and be told apart only by that one character.

The order is permit, then code, then a kotikunta decision, which is your registered municipality of residence. Most Kela benefits wait on the last of those and not the first, which is why people who already have a hetu are still sitting in a queue. The process has changed more than once in the last decade, so check the current one.

• Onks sulla henkilötunnus jo? Do you have a personal identity code yet? Asked of anybody newly arrived, because almost nothing starts without one.
• Sanoisitko hetun? Could you give me your identity code? Hetu is what people say. Henkilötunnus is what the form prints.

• Ilman hetua ei saa pankkitiliä. You can't get a bank account without an identity code. In practice most banks want the code and an address before anything opens.
• Sano hetu, niin mä katon. Give me your identity code and I'll have a look. Said across a pharmacy counter, out loud, and nobody lowers their voice to do it.

• Älä laita hetua mihinkään julkiseen. Don't put your identity code anywhere public. It goes a long way towards impersonating you. The counter is fine, a public post is not.
• Ensin lupa, sit hetu, sit kotikunta. First the permit, then the code, then the municipality. The order most benefits wait on. People who already have a hetu are still in a queue.

1. 1 Finland introduces new characters in personal identity codes to meet future demand Helsinki Times, 21 December 2023 - The full list of new century characters, the agency's statement that it had just run out of codes for the most common birth date, and the first Y code issued on 19 December 2023.
2. 2 hetu: structure and validation of the Finnish personal identity code Comprehensive R Archive Network - The DDMMYYCZZZQ layout, individual numbers 002 to 899 with the 900s reserved, odd and even encoding sex, and the modulo-31 check character over the thirty-one-character set.
3. 3 Henkilötunnuksen uudistaminen Finanssiala ry, Finance Finland - The status of the reform: the bill went to Parliament in February 2023 and lapsed, so the sex-linked individual number is still in force. Page last updated 17 January 2025.
4. 4 Vero - for individuals Verohallinto, Finnish Tax Administration - Tax is one of the systems the code keys into, and the tax card process depends on holding one.
5. 5 Kela - the Social Insurance Institution of Finland Kela - Residence-based social security, which follows registration and a municipality-of-residence decision.
6. 6 Kela card - do you need one? Kela - Health insurance entitlement, which is checked against this code electronically.
7. 7 Kielitoimiston sanakirja: henkilötunnus, tunnus Kotimaisten kielten keskus