A MODULAÇÃO DOS EFEITOS NAS DECISÕES TRIBUTÁRIAS DO STF: LIMITES, FINALIDADES E IMPLICAÇÕES JURÍDICAS

Abstract

This paper analyzes the application of the temporal effects modulation of the Brazilian Supreme Federal Court's (STF) decisions in tax matters, from the perspective of the principles of non-surprise and the State's fiscal responsibility. The research investigates how the use of this instrument, especially based on the argument of budgetary risk, subverts its purpose of protecting legal certainty, transforming it into a mechanism that validates unconstitutionality and penalizes the taxpayer. The study starts from the premise that the mismanagement of public spending and the insistence on maintaining the collection of evidently unconstitutional taxes constitute a "moral hazard" on the part of the State, whose consequence cannot be transferred to the citizen. To achieve the proposed objectives, the deductive method was used, with a critical analysis of the STF's jurisprudence, notably Extraordinary Appeal No. 574,706/PR (Topic 69). The results show that the pro-Treasury modulation, provided for in art. 27 of Law No. 9,868/99, has been used as a rule to protect the public coffers, to the detriment of the taxpayer's fundamental rights and the very normative force of the Constitution. It is concluded that such a practice constitutes an undue interference by the Judiciary in the legislative sphere, by prioritizing budgetary stability — weakened by the State's own inefficiency — over the duty to refund what was unduly collected, consolidating a barrier to fiscal justice and the full effectiveness of constitutional review.