Income Tax Act Article 119

All personnel of the tax authority shall keep in strict confidence, except to concerned parties and agencies, the amounts of income and income tax of any taxpayer, documentary evidences, and statements or documents made or provided by other parties. Any person found guilty thereof by the authority-in-charge or upon information of the injured party shall be subject to severe disciplinary action. Where such a person is also guilty of violating the Criminal Code, he/she shall further be referred to the court to be dealt with in accordance with law.Concerned parties and agencies as provided in the preceding paragraph refer to the taxpayer himself/herself/itself, his/her/its agent, attorneys, partners, successors, tax withholders, taxation agencies, control agencies, agencies receiving administrative appeal or handling administrative proceedings related to taxation, and such other agencies and personnel thereof as determined by the MOF.The furnishing of information by a tax authority to other government agencies for statistical purposes involving no disclosure of names of taxpayers is not subject to the confidence keeping restriction.Personnel of government agencies disclosing such information furnished by tax authority as provided in the first paragraph of this article shall be subject to punishment comparable to that imposable on personnel of tax authority.
中文原文 所得稅法第119條
稽徵機關人員對於納稅義務人之所得額、納稅額及其證明關係文據以及其他方面之陳述與文件,除對有關人員及機構外,應絕對保守秘密,違者經主管長官查實或於受害人告發經查實後,應予以嚴厲懲處,觸犯刑法者,並應移送法院論罪。
前項除外之有關人員及機構,係指納稅義務人本人及其代理人或辯護人、合夥人、納稅義務人之繼承人、扣繳義務人、稅務機關、監察機關、受理有關稅務訴願訴訟機關以及經財政部核定之機關與人員。
稽徵機關對其他政府機關為統計目的而供應之資料,並不洩漏納稅義務人之姓名者,不受保密之限制。
政府機關人員對稽徵機關所提供第一項之資料,如有洩漏情事,比照同項對稽徵機關人員洩漏秘密之處分議處。

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