A relativização da coisa julgada em matéria tributária

Abstract

The central focus of this work is the study of res judicata in tax matters and its treatment in the constitutional and procedural realms, under the current Brazilian Civil Procedure Code (CPC), both of which directly impact Tax Law. Thus, in the analysis of the theme, we begin with the basic concepts of the origin of the tax obligation and briefly develop some concepts about the main principles affected by the relativization of res judicata, especially after the judgments of themes 881 and 885 by the Supreme Federal Court (STF). In the study of the theme, it was essential not to overlook the treatment of res judicata at the constitutional level, given that it is a guarantee provided in the 1988 Federal Constitution. Therefore, we analyze the repercussions that this institute has concerning this matter, with emphasis on the two modalities of constitutional control. In the procedural realm, we address the definition of res judicata given by the CPC/15 and doctrine, which distinguishes it into material and formal res judicata, as well as the objective and subjective limits it encompasses. Finally, we examine how these three main fields influence the discussion of res judicata in tax matters. To do so, we analyze scenarios of modifying jurisprudence and, consequently, the modulation of its effects, involving the Theme 881 of the Supreme Federal Court. Subsequently, we provide a brief analysis of the judgment that gave rise to the thesis established in Theme 885 by the STF and unfold the relevant aspects of this discussion. Thus, we conclude that (i) in the balance between res judicata and free competition, res judicata should prevail, not only in compliance with the fundamental right that provides for it but also in accordance with the principle of legal certainty; (ii) tax law operates in a rigid decision-making environment, and therefore, jurisprudence should change gradually, as a sudden change, if unfavorable to the taxpayer, would imply a new obligation to pay taxes; (iii) for these reasons, it is necessary to modulate the effects of the decision when it leads to a change in jurisprudential understanding