The Central Bank of the Republic of China (Taiwan) Act Article 18

The Bank shall exchange stained or damaged notes and coins deemed to be unfit for circulation in accordance with certain standards, and destroy them according to law.The Bank may redeem currency issued. Currency redeemed shall no longer be legal tender. However, the redemption period shall not be less than one year, during which time holders may exchange redeemed currency with the Bank.
中文原文 中央銀行法第18條
本行對污損或破損而不適流通之紙幣及硬幣,應按所定標準予以收兌,並依法銷燬之。
本行對已發行之貨幣,得公告予以收回。
經公告收回之貨幣,依公告規定失其法償效力。
但公告收回期間不得少於一年,期內持有人得向本行兌換等值之貨幣。

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