Abstract: The author examines the essence of the category "good faith" and its implementation in specific legal institutions in the context of the concept of "smart regulation". Using the example of tax and civil law, it is investigated exactly how the category "good faith" is interpreted in the scientific literature, legislation and law enforcement practice, the main aspects of its direct and indirect application are analyzed. Based on the results of this analysis, the grounds for attributing the principle of good faith to the means of "smart regulation" have been identified, the main advantages of such categorization and recommendations for optimizing the use of the principle of good faith and its main manifestation in modern domestic tax law – the "anti-rejection rule" have been identified. Conclusions are drawn that the manifestations of "smart regulation" are not always innovative and poorly studied legal institutions. Finding them among the usual, ubiquitous legal means is no less important for the most effective, accurate use of the latter. For example, a correct understanding by the judicial authorities of the role of the general grounds for challenging transactions in bankruptcy (prevention and exclusive application) leads to the formulation of legal positions on their subsidiarity, preventing the use of this tool as ubiquitous. On the other hand, the consolidation of the anti-deviation rule in the tax legislation is generally correct, but not enough: there are no specific compositions of "evasive" offenses, which normalizes the widespread use of Article 54.1 of the Tax Code of the Russian Federation and the excessive detail and significance of the explanations of the tax authorities. The key assumption of the author is that the formation of an idea of these institutions as "smart regulation" will allow them to achieve the greatest effectiveness with the least legislative and law enforcement intervention.