First names must be in accordance with the Act on First Names and Surnames. A person may have no more than four first names. A child's first names must be reported to the Population Information System within three months of the child's birth. The child's parents inform either the baptising member of the clergy or the local register office of the names given to the child, so that the names can be registered in the Population Information System.
A person’s first name can be changed with an application to the local register office.
A child will receive the parents’ surname if the parents have a common surname. If the parents have different surnames, they must notify the local register office whose parent's surname the child will take, so the name can be registered the Population Information System. According to the Act on First Names and Surnames, in this instance the child may also receive a compound surname combining the surnames of both parents. If the parents already have a common child, the new child will receive the same surname as the older sibling.
A person's surname can be changed with an application to the local register office.