The Taxpayer Rights Protection Act Article 13

After a taxpayer files a recheck or administrative appeal, they may apply to the tax authority or the agency with jurisdiction of administrative appeal for examining, transcribing, copying, or taking photographs of information relevant to the tax assessment and penalty, to the extent necessary for claiming or protecting his or her legal interests.The tax authority or the agency with jurisdiction of administrative appeal shall not refuse to provide information, or provide incomplete information, in response to the application referred to in the preceding paragraph, unless there is one of the circumstances set out in Paragraph 2 of Article 46 of the Administrative Procedure Act, or in Article 51 of the Administrative Appeal Act, and the circumstance is stated clearly in the refusal.
中文原文 納稅者權利保護法第13條
納稅者申請復查或提起訴願後,得向稅捐稽徵機關或受理訴願機關申請閱覽、抄寫、複印或攝影與核課、裁罰有關資料。
但以主張或維護其法律上利益有必要者為限。
稅捐稽徵機關或受理訴願機關對前項之申請,除有行政程序法第四十六條第二項或訴願法第五十一條所定情形之一,並具體敘明理由者外,不得拒絕或為不完全提供。

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