Primary and Junior High School Act Article 49

Citizens older than school age who have not received primary and/or junior high school education shall receive supplementary compulsory education.Schools shall establish continuing education departments for the implementation of supplementary compulsory education.
中文原文 國民教育法第49條
已逾齡未受國民教育之國民,應受國民補習教育。
國民補習教育,由學校設進修部實施之。

English translation for reference only; the Chinese text prevails. Not legal advice.