Abstract: The subject of the research is the analysis of laws, and practical implementation of these laws, regulating the performance of tax liability by a taxpayer. The object of the research is the implementation of the Tax Code of the Russian Federation provisions to legal relations arising in the process of set-off of tax liabilities. The authors of the article examine such aspects of the topic as analysis of the institution of good faith of a taxpayer including actions that cause unjustified tax benefit and performance of tax obligations and actions of credit organisations that support performance of these obligations by a taxpayer. The methodological basis of the research is the research methods, in particular, general research methods (logical method, systems analysis, deductive method, analytical method, generalisation) and specific research methods (comparative law, formal law, etc.). These methods allowed to study legal phenomena from the point of view of their interaction and interdependence, define tendencies and make generalisations and conclusions. The main conclusions of the research include the authors' recommendations on how to improve tax laws including introduction of the provisions of the judicial practice in the Tax Code of the Russian Federation. The authors also offer their own definition of taxpayer's good faith, describe specific features and evaluation criteria thereof. These conclusions may serve as the basis for further researches as well as teaching law and finances.