Recently, to effectively obtain taxpayers’ tax information and to more conveniently collect taxes, tax collection authorities often ask notaries to provide taxpayers’ notarizing or certifying information according to Article 30 of Tax Collection Act. Despite being stated in the Article 14 of the Notary Act which affirms the notary’s confidentiality obligation, it is in fact hard for notaries in Taiwan to performance their duties as understandably, they are under considerable pressure from tax collection authorities in tax investigations. On the other hand, in Germany, there is no rule against a notary’s right to refuse to cooperate (which includes the right to refuse testimony and presentation) as there is in Taiwan. However, this paper advocates that notaries should be given “the right to refuse cooperation” in tax investigation in order to protect the “relationship of trust” between notary and their client as well as to keep notary’s social role remaining a neutral third party. As for now, the essential solution is indeed to amend the law to plug this loophole. However, before amending, tax collection authorities and court should also apply by analogy Article 182 of the Code of Criminal Procedure on their own initiative to provide notary the right to refuse cooperation in tax investigation.