Enforcement Rules of the Income Tax Act Article 88

A taxpayer that lends his or her property to others without any consideration shall enter into a no-consideration lending agreement with the other party, with such agreement being attested by two third-party persons and notarized under the relevant articles of the Act on Authentication.
中文原文 所得稅法施行細則第88條
將財產無償借與他人使用者,應由雙方當事人訂立無償借用契約,經雙方當事人以外之二人證明確係無償借用,並依公證法之規定辦竣公證。

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