The study aims to present the meaning of general tax law principles resulting from the draft of the New Tax Ordinance Act on the process of tax law interpretation. A detailed analysis covers three principles: the principle of determining the content of tax law provisions, including the structure of the tax to which these provisions apply, the principle of resolving doubts in favor of the obliged, as well as the principle of balancing the legitimate interest of the obliged and the public interest. As part of the work, the following research hypotheses regarding these principles have been positively verified: the principles will have a significant impact on the interpretation of tax law provisions contained in the laws shaping the construction of individual taxes, they will also apply to other tax law provisions, additionally they will affect non-tax provisions, the application of which affects the operation of tax law provisions.