The aim of the work is to answer the question of the need for the legislator to deliberately underspecify the concepts authorizing the Head of the National Revenue Administration to waive fiscal secrecy. The research problem addressed in this article is the essence of the legislator’s failure to define the concepts authorizing the Head of the National Tax Administration to waive fiscal secrecy and their validity in the context of guaranteeing taxpayers’ rights. Data and information held by tax authorities may, if appropriate conditions exist, be released from fiscal secrecy. This makes the data public. For this to happen, appropriate conditions must exist. This includes: the premise of important public interest, which must always be present, and tax control or the constitutional right of citizens to be reliably informed about the activities of tax authorities and the openness of public life. It is worth emphasizing that data protection in tax administration not only protects the privacy of citizens and the security of their basic personal rights, but also builds public confidence in state activities and maintains the integrity of the tax system. The indicated premises are general clauses that allow for their evaluation, which gives great freedom in making “decisions” on whether or not to consent to the disclosure of information covered by fiscal secrecy. The Head of the National Administration has the competence to waive fiscal secrecy. This raises certain doubts regarding the discretion in making “decisions” and their correctness in the context of guaranteeing taxpayers’ rights. Therefore, the research hypothesis of this work assumes that the legislator may have left such a structure on purpose because it ensures increased security, and moreover, the consent of the Head of the National Revenue Administration to waive fiscal secrecy must always be based on at least two positive premises, including at least one of there must be an important public interest in them. The lack of definition of the essence of fiscal secrecy, which would constitute a legal definition, should also be questioned. Data security and information protection in tax administration are key issues due to the sensitive nature of tax data stored and processed. It is worth emphasizing that data protection in tax administration not only protects the privacy of citizens and the security of their basic personal rights, but also builds public confidence in state activities and maintains the integrity of the tax system. The work uses the formal-dogmatic method of analyzing legal acts, which is the main method used in legal sciences. The method of critical literature analysis was also used.