Business Entity Accounting Act Article 8

(Bookkeeping Language)Except for Arabic numerals used in numbering, all recording of business transactions must use the domestic language; If it is necessary to include remarks in or concurrently use any foreign language or local language, domestic language must be predominant.
中文原文 商業會計法第8條
商業會計之記載,除記帳數字適用阿拉伯字外,應以我國文字為之;其因事實上之需要,而須加註或併用外國文字,或當地通用文字者,仍以我國文字為準。

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