Act of Military Service System Article 25

The basic training of Substitute Service is executed jointly by the Ministry of Interior and the Ministry of National Defense.Total period of serving the Substitute Service along with the basic training can not be less than the period of Active Service of the Standing Soldier Service; can not be less than the period of Military Training of Standing Soldier Service while the induction of Active Service of Standing Soldier Service is suspended. During the period of Substitute Service, the identity of military personnel in Active Service will never be granted.Those Conscription Age Males whose year of birth are earlier than the suspended induction of Active Service of Standing Soldier Service and who have not been inducted or re-inducted to serve, shall serve the Substitute Service for one year.
中文原文 兵役法第25條
替代役之基礎訓練,由內政部會同國防部辦理。
服替代役期間連同基礎訓練,不得少於常備兵役現役役期;停止徵集常備兵役現役後,不得少於常備兵役軍事訓練期間。
服役期間,均無現役軍人身分。
停止徵集服常備兵役現役年次前之役齡男子,未經徵集或補行徵集服役者,應服替代役,為期一年。

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