Personal identity code

The personal identity code is a means of identification that is more specific than a name. Several people may have the exact same name but there are no two persons with exactly the same personal identity code. The code remains unchanged throughout the person’s lifetime. Personal identity codes were introduced in Finland in the 1960s.

Parents of newborn children born in Finland need not take any measures to obtain a personal identity code for the child. The hospital provides the necessary details of all births to the Population Information System, and when the child’s birth is registered, a personal identity code is issued for him or her. After registration, a form containing the personal identity code is sent to the parents. This form (named “Lapsen tietojen ilmoittaminen” in Finnish) is used to notify the population register authorities of the child’s name and native language.

For a Finnish citizen born abroad, a personal identity code is issued when the local register office, by request of the parents, registers the child in the Population Information System. You find additional information on, e.g., the documents required on the website of Local Register Offices.

For a foreign citizen moving to Finland from abroad, a personal identity code is issued when he or she has been registered in the Population Information System.

Changing the personal identity code

The Finnish personal identity code is individual to its holder and is intended to be permanent. A new personal identity code can only be issued when this is vital in order to provide protection to a person in circumstances where the health or safety of that person is under obvious and permanent threat, or when the original code has been repeatedly abused by a person other than to whom it was issued (Act on the Population Information System and the Certificate Services of the Population Register Centre, Act 661/2009).

A prerequisite for considering the issue of a new personal identity code is that the abuse of the original personal identity code has caused the proper holder of the code significant financial or other hardship and that the issue of a new code will effectively prevent further harm caused by the abuse. The need for a new personal identity code can be evaluated on the basis of a threat assessment performed by the police in e.g. situations of witness protection. The decision to issue a new code is taken by the Population Register Centre.

A new personal identity code may be entered in the Population Information System also if a person has pursuant to the Gender Confirmation of Transsexual Individuals Act (563/2002) been confirmed as belonging to the opposite gender. In this case, the issue of a new code is decided by the local register office.

What does the personal identity code tell us?

Anna Suomalainen’s personal identity code is 131052-308T. The first part of it – 131052 – tells us the day, month and year of her birth, in the form ddmmyy. Thus, her date of birth is October 13, 1952.

The sign after the date of birth tells us in which century she was born. In Anna’s case the sign is a hyphen (-) as she was born in the 1900s. Those born in the 1800s have a plus (+) and those born in the 2000s have the letter A.

The individual number, which for Anna is 308, distinguishes persons with the same date of birth from each other. Men have an odd number and women an even number. In practice, all individual numbers issued are within the range of 002 to 899.

Calculating the control character 

The control character can be a number or a letter: for Anna, it is a T. It is obtained by dividing the nine-digit number consisting of the date of birth and the individual number by 31.

Hetu_graafi_englanti_1.9.14The control character is determined on the basis of the remainder according to the table to the left.

When the remainder corresponding to the control character in the personal identity code is calculated and the calculation returns a decimal number, the remainder is established as follows: the decimals following the whole number are multiplied by 31 and the resulting number rounded to the nearest whole number. The following example illustrates the method:

The personal identity code of Anna Suomalainen is 131052-308T. The T is arrived at by taking the number 131052308 and dividing it by 31. The result of the division, depending on the precision of the calculator, may appear as e.g. 4227493.8064516129032258064516129.

Taking the number series .8064516129032258064516129 appearing after the decimal point and multiplying it by 31 gives the result of 24.9999999999999999999999999, which rounded to the nearest whole number is 25. The table of corresponding control characters then provides the T in the personal identity code.


Population Information System personal identity code