Regulations Governing Application by Draftees-to-Be for Substitute Services Article 14

Circumstances such as adoption, divorce, termination of an adoption or age change for a draftee or his family members shall be limited to the household registration made before December 31 of the year the draftee turned 18, or the household registration made two years before the application for substitute service is filed. It shall be limited to the household registration made before December 31 of the year the draftee turned 15 if the draftee himself was adopted.
中文原文 役男申請服替代役辦法第14條
役男或其家屬有收養、離婚、終止收養或年齡變更等情事,以該役男十八歲之年十二月三十一日前或提出申請服替代役二年前,已辦竣戶籍登記者為限。
但役男本人被收養者,以役男十五歲之年十二月三十一日前,已辦竣戶籍登記為限。

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