Tax Collection Act Article 29

For the tax payment refundable to a taxpayer, the tax authorities shall offset the refundable taxes payable against the delinquent taxes receivable from a said taxpayer, and shall forthwith inform, by notice, said taxpayer of such offset.
中文原文 稅捐稽徵法第29條
納稅義務人應退之稅捐,稅捐稽徵機關應先抵繳其積欠。
並於扣抵後,應即通知該納稅義務人。

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