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.
The Finnish personal identity code is issued to Finnish citizens born in or outside Finland on the basis of a birth certificate. Parents of newborn children born in Finland need not take any measures to obtain a code for the child, as the hospital provides details of all births to the Population Information System and a personal identity code is registered for the child in the Population Information System when the child’s birth is registered.
Foreign citizens whose residence in Finland is permanent or exceeds more than one year are also issued a personal identity code. Persons staying in Finland on a temporary basis, and in some cases family members residing abroad as well, can also be issued the code if this is deemed necessary on the basis of the law. Foreign citizens should contact the local register office of their place of residence for registration. Foreign citizens staying in Finland on a temporary basis can also register at a local tax office, the Finnish Immigration Service or a branch of the Social Insurance Institution of Finland (Kela). Foreign citizens residing in Finland under diplomatic status cannot be issued a personal identity code.
The personal identity code is needed in a variety of situations
You need your personal identity code to be able to apply for pensions and other benefits. It is also needed for the payment of wages, salaries and fees. The code is also essential in bank transactions, and your bank will require it when you are opening an account.
Careful use of the personal identity code reduces the risk of error in registers and therefore improves your data protection. But, the code is not always needed in every situation. Your name is often enough.
Issue of new 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. Practically all individual numbers issued are within the range of 002 to 899.
The control character can be a number or a letter: Anna’s is T. It is obtained by dividing the nine-digit number consisting of the date of birth and the individual number by 31.
The control character is determined on the basis of the remainder in accordance with the table to the left.
Calculation of remainder
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. A table of corresponding control characters then provides the T in the personal identity code.
