henkilötunnin

Henkilötunnus, often shortened to hetu, is the Finnish personal identity code. It is a unique eleven-digit number assigned to every resident of Finland and also to foreigners who have a legal connection to the country, such as a work permit or residency. The primary purpose of the henkilötunnus is to identify individuals in various official contexts, including healthcare, taxation, social security, and banking.

The structure of the henkilötunnus provides information about the individual. The first six digits represent the date of birth in DDMMYY format. The seventh digit is a separator, which is a hyphen for most people, but a plus sign (+) or an 'A' for those born on the 1st or 2nd of February respectively, or for specific older registrations. The next three digits form a personal number, which is assigned sequentially. The final digit is a checksum, calculated using a specific algorithm to ensure the validity of the code.

The Finnish Social Insurance Institution (Kela) is responsible for assigning and managing the henkilötunnus. It is a crucial piece of personal data in Finland and is treated with strict privacy regulations. Unauthorized use or disclosure of a henkilötunnus can lead to legal consequences. While essential for official purposes, individuals are advised to be cautious about sharing their henkilötunnus unnecessarily.