27/01/2026
The Brazilian Supreme Federal Court (STF) has scheduled for February 25 two highly significant tax cases affecting companies across multiple sectors. The discussions involve structural issues of the Brazilian tax system and, according to estimates contained in the fiscal risk annex of the 2026 Budget Guidelines Law (LDO), may result in an impact of up to BRL 51.9 billion for the Federal Government if the rulings are unfavorable to the tax authorities.
The theses under review are not new, but they return to the Court’s docket at a decisive moment, with potential binding effects and direct consequences for corporate tax planning.
The first case concerns the exclusion of the Municipal Service Tax (ISS) from the calculation base of PIS and Cofins, with an estimated fiscal impact of BRL 35.4 billion.
The controversy is directly related to the constitutional concept of gross revenue and is considered one of the main extensions of the so-called “thesis of the century” (Theme 69/STF), in which the STF ruled for the exclusion of ICMS from the base of social contributions. In that precedent, the Court held that tax amounts merely pass through the taxpayer’s cash flow and do not constitute its own revenue.
At present, votes already cast indicate a tendency favorable to taxpayers, although the procedural history of the case—marked by requests for review and case withdrawals—calls for caution. As the matter has general repercussion, the decision will have binding effect, directly impacting ongoing administrative and judicial disputes.
The second relevant case addresses whether presumed ICMS credits should be included in the calculation base of PIS and Cofins, with an estimated fiscal impact of up to BRL 16.5 billion.
The discussion involves not only the legal nature of such credits, but also sensitive issues of fiscal federalism, particularly regarding the Federal Government’s ability to tax tax incentives lawfully granted by the States.
The case has already begun in the Virtual Plenary, with a majority favorable to taxpayers, but remains unresolved following a request for review and case withdrawal, which will lead to a new analysis by the physical Plenary. Currently, there is a nationwide suspension of proceedings dealing with the matter, reinforcing the importance of closely monitoring the STF’s final decision.
The cases scheduled underscore the need for strategic attention by companies, especially those with a significant PIS and Cofins burden or that benefit from State tax incentives.
Depending on the outcome of the STF’s rulings, opportunities may arise for recovery of amounts, revision of tax practices, reassessment of contingencies, and direct effects on ongoing administrative and judicial proceedings.
The team at Dupont Spiller Fadanelli Advogados continuously monitors the STF’s agenda and remains available to clarify any questions regarding this matter.
