Mothers wanting to avoid the automatic family registration have to start a lengthy and costly court battle to sever the family relationship between their children born after divorce and their former spouses.

Thanks to the revision of the Civil Code, however, the registration of children born after divorce can be simply confirmed by obtaining permission from the family court, the officials said.

The revision will take effect immediately as the Cabinet meeting approved it Tuesday, they said.

The legal amendment came after the Constitutional Court ruled in May 2015 that the Civil Code's clause on automatic family registration of post-divorce children infringes on the people's constitutional rights based on gender equality.

"A simple request for permission will now replace lawsuits to prove which side the children born within 300 days after divorce are registered to," an official said.

"Biological fathers can also easily prove their paternity through the revised procedures," he added.

The family court will determine paternity through blood and gene tests and review of the separation period, officials said. (Yonhap)