In the Polish tax law system, general principles of law and tax procedure play an extraordinary role in the taxpayer’s rights protection structure. Their importance is difficult to overestimate in the context of frequent doubts related to the practical aspect of compliance with tax law provisions. This is because the principles constitute the axiological basis for the functioning of the law. Additionally, during the period of dynamic changes in regulations, the role of the principle of legal certainty or the principle of the citizens’ trust in government becomes more important. This is because it is difficult to reconcile the principle of legal certainty with the situation when the legislator decides to terminate the interpretation without giving detailed grounds for doing so and referring only to the institution of tax avoidance. The practice involving suspending the limitation period by an authority in connection with instituting penal and fiscal proceedings, when it was instituted without grounds, is also unacceptable. Such attitude explicitly contradicts the principle of carrying out proceedings in a manner that creates trust in the authorities. Planned amendments aimed at organising the institution in question should be considered positive. At the same time, in order to ensure proper protection of the obligated party (including a taxpayer), it is highly desirable to formulate the principles that are not expressed in currently binding regulations, but which can otherwise be derived from the provisions of the Constitution of the Republic of Poland.