In a landmark ruling Thursday, the Supreme Court said that marriage can be nullified after divorce under "special circumstances," allowing separated couples to be freed from potential legal complications and obligations entailing matrimony.

The Article 815 of the Civil Act states that a marriage is void if the two parties did not both consent, or if it occurs between certain close relatives. But a precedent set in 1984 by South Korea's highest court has made it impossible to annul a marriage post-divorce, citing a lack of actual benefits from the annulment.

Thursday's ruling involved a woman divorcing her husband of three years and requesting the marriage itself to be invalidated, saying that the couple registered their marriage without her consent.

The Supreme Court specified three cases in which the marriage itself can be nullified after divorce. One is when a marriage occurred without consent -- such as under threat, confusion or distress such as in this case -- another is when the marriage is coerced by parents, and the third is when one's spouse is a foreign national and he or she returning to their home caused the divorce.

Annulment and divorce both end a marriage, but the details are slightly different. Couples are not entirely free from all the legal obligations that come with marriage even after a divorce.

South Korea's law recognizes both the separate assets of each spouse and the marital property. When a spouse has a debt that is directly linked to the common property, the other spouse is obligated to share responsibility of the said debt even when separated. Nullifying the marriage itself could potentially free the divorced spouse from such legal complications.

Invalidating a marriage post-divorce could also potentially affect the dispute concerning the pension split. South Korean law states that people can receive a share of the pension of their divorced partner if the marriage lasted at least five years.

The law states that any family connections made by marriage are invalidated after divorce, but the trace of marriage does not completely disappear after they part ways.

The Criminal Act states that certain crimes committed by relatives are exempt from punishment and some can be punished only if the victim files for charges. In a few cases, one’s marital status affects legal proceedings even after the divorce.

For example, if someone committed fraud against their father-in-law during the marriage, the victim himself would have to file charges, even after the perpetrator had divorced his daughter. But an annulled marriage would nullify that particular relationship, meaning the fraud would be subject to criminal punishment even without the intervention of the father-in-law in question.

It is still unclear exactly how exactly the new precedent will be applied, as the court would have to deliberate on specific details of individual cases. As mentioned in the Supreme Court ruling, annulment itself would likely be a very rare case.