South Korean nationality law

South Korean nationality law defines who is a South Korean citizen, as well as the procedures by which one may be naturalized into South Korean citizenship or renounce it.

South Korean nationality can be acquired in a number of ways:

Under the Constitution of South Korea, North Korean citizens are also recognized as South Korean nationals. However, in practice, a formal evaluation needs to take place which requires documentary proof of North Korean nationality. Additionally, North Korean citizens do not have automatic protection from South Korea per se, since those with criminal histories are not accepted as South Korean citizens.

Additionally, South Korean law defines the term "Overseas Korean" as referring to South Korean nationals who reside overseas as well as "Koreans with a Foreign Nationality." The latter group is composed of former South Korean nationals who gave up their South Korean nationality (but barring those who did so to deliberately evade military service, at least until age 36) and children and grandchildren of former South Korean nationals. It is important to note that not every descendant of a South Korean can be counted as an "Overseas Korean" or "Korean with a Foreign Nationality" under this law. For example, a 25-year-old man who was born a South Korean national overseas but whose birth was unreported will have no documentation to prove his status as a former South Korean national, and can only gain status as an Overseas Korean if one of his parents or grandparents gave up South Korean nationality. Also, those who fall under Article 7 of the Addenda (Special Cases of Acquisition of Nationality for Persons of Maternal Line By Adoption of Jus Sanguinis to Both Lines of Parents) but failed to acquire South Korean nationality are not able to gain the status of an Overseas Korean unless the mother or a maternal grandparent has lost South Korean nationality.

Koreans in Japan who have South Korean nationality and Special Permanent Residence in Japan do not have a Resident registration number and cannot apply for a new passport from a South Korean embassy while outside Japan.

There are three types of naturalization under South Korean law:

Those who acquire South Korean nationality by naturalization normally must give up foreign nationality within six months or forfeit South Korean nationality. An exception to this is draft-age males, who must complete or be exempted from military service before being allowed to forfeit Korean nationality.

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Wikipedia