Changing a Child's Surname and Family Origin

In a decision of December 11, 2009 (2009스23), the Supreme Court set out how this is judged. First, the court looks at the disadvantages of not changing the surname, such as obstacles to emotional unity within the family and prejudice at school or in social life. Next, it looks at the disadvantages of changing it, such as confusion about identity and a break in ties with the biological father or siblings. It then compares the two from the child's point of view and decides in the direction that helps the child.

The same decision said that if the change is necessary for the child's welfare beyond mere personal preference, and there is no improper purpose such as hiding a crime or avoiding legal restrictions, permission should in principle be granted.

The law contains no provision making the biological father's consent a requirement. The court may hear the biological father's opinion, but it looks more at the actual relationship he has had with the child than at the objection itself. If there has been no visitation and no child support for a long time, that can support the need for the change.

On the other hand, if the request looks like a way to pressure the other parent in a child support dispute, it may be judged unfavorably. The petition should focus on the difficulties the child is facing now and the stability the child will gain after the change, rather than on the other parent's faults.

A change of surname and family origin (성·본 변경) only changes the name; the legal father–child relationship with the biological father remains. Inheritance, support, visitation and the duty to pay child support all remain.

Full adoption (친양자 입양) is a much weightier procedure that ends the family relationship with the biological parents and makes the child the new parent's own child. To fully adopt a spouse's child, the couple must have been married for at least 1 year, and in principle the biological parents' consent is required (Civil Act Article 908-2). In a stepfamily, first decide which is the right fit.

Even when the decision granting permission becomes final, the family relationship register does not change by itself. You must file a report with the city, district, town or township office of the place of family registration or address within 1 month of the date the decision became final, and a late report can lead to an administrative fine of up to KRW 50,000 (Article 122 of the same Act).

If there are several siblings, a separate request must be made for each child, so decide in advance whether to file together so the siblings do not end up with different surnames.