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Common-law relationship

A common-law relationship is a relationship where spouses live together but are not married to each other. In Finland, beginning a common-law relationship, the rules of the relationship and ending the relationship, are each couple’s own private affair. Common-law relationships are not registered anywhere.

Unlike in marriage

  • a common-law husband and wife have no maintenance liability to each other
  • they do not inherit from each other
  • a common-law husband or wife cannot receive the surviving spouse's pension if their partner dies

You can adopt a common last name if

  • you have children together or
  • you have lived together for at least five years

If you want to have a common last name, send an application for a change of name to the Digital and Population Data Services Agency.

If you and your partner permanently live in the same accommodation, you belong to the same household. This is significant, for example, when applying for housing allowance from Kela.

Read more about housing allowance for unmarried cohabitants on the InfoFinland web page Housing allowance.

Link redirects to another websiteDigital and Population Data Services Agency

Changing last name

A common-law relationship entered into abroad

A common-law relationship can be a basis for getting a residence permit. The authorities always consider the granting of a residence permit case-specifically.

Children of parents who are in a common-law relationship

Acknowledgement of paternity (Isyyden tunnustaminen)

If you are living in a common-law relationship and you have a child, the child’s paternity must be acknowledged. If paternity is not acknowledged, the child is officially fatherless and the mother is alone responsible for the child’s maintenance and care, even if you live together. A man can acknowledge his paternity during the pregnancy at a maternity clinic. When the child is born, paternity can be acknowledged at your municipality’s child welfare supervisor’s office. The acknowledgement of paternity is confirmed by the Digital and Population Data Services Agency.

When paternity has been confirmed

  • the child can be given the father’s name
  • the father can act as the child’s guardian either together with the mother or alone. A guardian (huoltaja) is a person who is responsible for a child’s care and upbringing.
  • the father is obliged to participate in the child’s maintenance
  • the child has inheritance rights in relation to his or her father and paternal family and vice versa
  • the child has a right to survivors' pension if the father dies

If the father does not acknowledge his paternity, the mother can bring suit against him for the confirmation of paternity.

Acknowledgement of maternity

The Maternity Act is in force in Finland. According to the Act, a child may have two mothers. The woman who gave birth to the child is always the mother of the child. A second mother may be recognised for the child if:

  • the child is born as a result of fertility treatment to the mother and her female partner or spouse,
  • both parents consented to the fertility treatment, and
  • a father cannot be confirmed for the child.

Maternity must also be acknowledged and confirmed when the parents are married.

When maternity has been confirmed,

  • the child can be given the last name of either mother or their common last name,
  • both mothers must contribute to the child’s maintenance,
  • the mothers may act as legal guardians of the child either jointly or alone, and
  • the child has inheritance rights in relation to both his or her mothers and their families.

Maternity can be acknowledged during pregnancy at the maternity clinic or after birth by visiting the municipal child welfare officer. The Digital and Population Data Services Agency is responsible for confirmation of maternity.

Child’s last name in a common-law relationship

When a child is born in a common-law relationship, the child can have

  • the mother’s last name, or
  • the father’s last name if paternity has been confirmed, or
  • the non-birth mother’s last name if maternity has been confirmed, or
  • the parents’ common last name, or
  • a double last name formed by combining the parents’ last names.

If the parents do not have a common last name but they have children together, the child will have the same last name as his/her siblings.

You can apply for a common last name with your common-law spouse if

  • you have lived together for at least five years, or
  • you have a child together.