The Supreme Court has ruled that the newly revised Civil Act, which is free of unconstitutionality, must be applied to lawsuits that were pending in court at the time of the 2024 Constitutional Court decision. The 2024 decision had ruled that the old Civil Act clause, which guaranteed a forced share of inheritance even to family members who committed depraved acts, was unconstitutional.

This means that the amended Civil Act, which deprives individuals of inheritance rights if they have gravely violated their duty of support, will be applied.

However, co-heirs who became aware of the inheritance of a depraved family member before the amended Civil Act took effect, such as the parties in this trial, must file a request for the forfeiture of inheritance rights with the family court by September 16 of this year to make such a claim in a forced share case.

The Supreme Court's First Division (led by Justice Shin Sook-hee) on Thursday (June 25) overturned an appellate court's partial ruling in favor of the plaintiffs and remanded the case to the Gwangju High Court. The lawsuit, seeking to confirm the invalidity of a will, was filed by sibling B and others against sibling A, who had inherited most of their father's estate.

A inherited most of the estate after their father's death in 2021, and the older brother, B, filed a lawsuit demanding his forced share.

A forced share refers to a portion of an estate that must be legally reserved for individual family members, even if the deceased left a will.

It was introduced in 1977 to prevent a specific heir from monopolizing an inheritance, but criticisms persisted that it lagged behind social changes and excessively infringed on individual property rights.

In April 2024, the Constitutional Court delivered a decision of nonconformity to the Constitution regarding Article 1112 of the Civil Act, which did not separately specify grounds for the forfeiture of a forced share.

The Constitutional Court stated, "Recognizing the forced share of an heir who has committed depraved acts, such as abandoning the deceased for a long period or subjecting them to mental or physical abuse, runs contrary to the legal sentiments and common sense of the general public."

The Constitutional Court also ruled Article 1118 of the Civil Act unconstitutional. The article did not recognize the "contributory share" of heirs who supported the deceased for a long time or contributed to the formation of the inherited estate, with the court noting that "it creates an unfair and unreasonable situation that denies the deceased's intention to compensate the contributing heir."

However, for the sake of legal stability, instead of declaring the law immediately unconstitutional, the Constitutional Court ordered the National Assembly to revise the law by December 31, 2025, allowing the temporary application of the existing clauses until the revision.

In the lawsuit involving A's family, the key issue was whether to apply the old forced share clauses, which had been ruled nonconforming to the Constitution.

In the second trial, A argued, in line with the purpose of the Constitutional Court's decision, that B's forced share should not be recognized because B had committed depraved acts while A had supported their father.

However, in November last year, the appellate court, like the first-instance court, ruled that A must return the deficit of the forced share to B.

The court reasoned that it had no choice but to base its judgment on the old forced share clauses, in accordance with the temporary application of the old law.

The Supreme Court, however, held a different view.

The Supreme Court stated, "The parts of the old law that do not separately specify grounds for the forfeiture of a forced share, and the parts that do not apply the Civil Act clauses on contributory shares to forced shares, must be considered to be in a state of 'suspended application.'"

It explained, "Although the addenda of the amended Civil Act state that the new clauses apply retroactively only to cases where inheritance commenced after April 25, 2024—the date of the Constitutional Court's decision—the retroactive effect of the nonconformity decision must be deemed to extend to cases (parallel cases) that were pending in court at the time of the decision and for which the old clauses served as the premise of the trial."

This means that for such parallel cases, the newly revised clauses, from which the unconstitutional elements have been removed, will apply.

Following the Constitutional Court's decision, the National Assembly passed the so-called "Goo Ha-ra Act" in August 2024, which deprives parents who neglect their duty to raise their children of inheritance rights.

The bill was named after the late singer Goo Ha-ra, who passed away in 2019, after her older brother petitioned for the legislation, pointing out that their biological mother, who had abandoned Goo when she was a child, was attempting to claim half of her estate.

In March of this year, the law was further amended to restrict the inheritance rights of all heirs—including lineal descendants and spouses, in addition to lineal ascendants—if they have gravely violated their duty of support.

Under the law, individuals who gravely violate their duty of support to the deceased can be barred from receiving the estate through a declaration of forfeiture of inheritance rights by the family court.

Thanks to the Supreme Court's ruling, the parties in this trial now have a path to have their case re-evaluated in accordance with the intent of the amended law.

According to the amended law, a co-heir must file a request for the forfeiture of inheritance rights with the family court within six months of learning that a person who violated their duty of support has become an heir.

However, co-heirs who became aware of this before the amended law took effect—namely, those like A who were already in the middle of a legal battle over a forced share—must file a request for the forfeiture of inheritance rights with the family court by September 16 of this year, which is within six months of the enforcement date of the amended Civil Act (March 17 of this year), to claim grounds for the forfeiture of a forced share.