STF Excludes ISS from the PIS and Cofins Calculation Basis: What Changes for Lucro Presumido and Lucro Real Companies

Service companies have lived for decades with a quiet distortion in how they calculate PIS and Cofins: the calculation of these federal contributions typically includes, within taxable gross revenue, the amount of ISS, a municipal tax that the company merely collects on behalf of the local tax authority, without that amount ever representing an actual gain for its cash flow. In practice, this means paying a federal contribution on an amount that was never truly the company's revenue.

Brazil's Supreme Federal Court (STF) put an end to this controversy in October 2026, when it ruled on Extraordinary Appeal 592,616, with general repercussion recognized under Topic 118. By majority vote, the justices established the rule that the amount corresponding to ISS does not form part of the calculation basis for PIS and Cofins, since it is a mere financial inflow that passes through the company's accounting without any definitive character. The ruling mirrors, for ISS, the logic the STF itself had already established years earlier for ICMS, in what became known as the tax case of the century, and it settles an understanding that companies in virtually every service sector had been waiting for.

The reasoning behind the decision

The central point of the ruling lies in the distinction between revenue or turnover, on one hand, and mere transitory financial inflows, on the other. The reporting justice, Celso de Mello, and Justice Luiz Fux, whose vote broke the tie after years of proceedings, held that the ISS amount embedded in the price of a service does not represent an increase in the service provider's assets, but rather a resource that, by force of law, belongs to the municipality. Since Article 195, section I, item b, of the Federal Constitution, as amended by Constitutional Amendment 20/98, authorizes PIS and Cofins to be levied on revenue or turnover, taxing the ISS amount as well would mean expanding the constitutional basis of these contributions beyond what the Constitution itself allows.

The vote was tight: five justices followed this line, while five others, including Alexandre de Moraes, Gilmar Mendes and Edson Fachin, held that ISS does indeed form part of the company's assets before being passed on to the municipality and should therefore remain in the calculation basis. The tiebreaker fell to Fux, which shows that the matter, although now settled, involved significant technical disagreement within the Court itself.

Why the precedent applies to virtually every service company

Since the ruling was issued under the general repercussion procedure, the rule established under Topic 118 must be mandatorily applied by other courts across the country in cases discussing the same issue. This means that service companies subject to ISS, from consulting firms to clinic chains, gyms, technology companies, construction firms, transportation operators and telecom providers, among many other activities, now have solid case law grounds to exclude the municipal tax amount from the PIS and Cofins calculation basis.

It is worth noting that the decision does not apply to companies that sell goods without providing services, whose equivalent discussion involves ICMS, already settled earlier by the STF itself. But for those who issue service invoices and collect ISS, the practical effect is direct: a smaller taxable base, lower contributions owed and, potentially, the right to recover amounts wrongly paid over recent years.

Lucro Presumido (deemed profit regime): where the opportunity lies

Companies that opt for the Lucro Presumido regime generally calculate PIS and Cofins under the cumulative system, with combined rates of 3.65% on gross revenue, with no right to credits on inputs. Under this regime, any reduction in the calculation basis has a direct and immediate impact on the contribution owed, since there is no credit offset mechanism to soften the effect. For service providers with tight margins and high municipal ISS rates, especially those subject to rates of 4% or 5%, the exclusion represents a recurring cash gain, month after month, in addition to the possibility of recovering amounts overpaid in the last five years, subject to the statute of limitations applicable to tax refund claims.

These companies are advised to review their contribution calculation records, clearly separating the ISS amount shown on each service invoice, in order to accurately gauge both the future impact on current calculations and the potential to recover past credits, whether through an administrative route or through their own lawsuit.

Lucro Real (actual profit regime): a more technical but equally relevant effect

Companies under the Lucro Real regime, subject to the non-cumulative PIS and Cofins system, with combined rates of 9.25%, but entitled to credits on certain costs and expenses, also benefit, although the practical effect requires a more careful calculation. Since excluding ISS reduces the contributions' debit base without changing the credits already taken, the result tends to be an effective reduction in the net amount owed. Larger service companies, with more complex tax structures and a significant volume of ISS collected, may see substantial financial impacts when the recalculation is done retroactively, considering the period not yet barred by the statute of limitations.

For corporate groups with multiple branches in different municipalities, each with its own ISS rate, the review tends to be even more relevant, since the spread across municipal rates can generate substantial amounts when consolidated at the national level.

Points of caution before taking action

The Supreme Court did not, in this ruling, address the modulation of the decision's effects, meaning it did not define whether the rule applies only from now on or also retroactively without restriction. This point may still be examined further if any of the parties files a motion for clarification, the appropriate remedy to clarify or complete the ruling. Until that is resolved, there remains some uncertainty about the exact time frame for recovering credits, which reinforces the importance of documenting the company's position now and, where applicable, filing a lawsuit to secure the right to a refund before any unfavorable modulation is decided.

Another practical point is that the Brazilian federal tax authority (Receita Federal) tends to resist, administratively, the immediate application of the rule in offset proceedings filed through PER/DCOMP, even in the face of a binding STF precedent, which in many cases makes the judicial route a safer and more predictable option for companies seeking to recover amounts wrongly paid, rather than waiting for spontaneous adjustment of ancillary tax obligations.

The STF's ruling on Topic 118 consolidates a broader movement in Brazilian case law to refine the calculation basis of social contributions, removing from it amounts that never actually represented new wealth for the taxpayer. For business owners and financial managers, now is the time for review: gather the history of payments made, identify the volume of ISS embedded in taxed revenue and assess, with the support of specialized tax advisors, the most suitable strategy for each case, whether adjusting current calculations or pursuing recovery of amounts paid in recent years. Rulings of this magnitude rarely translate into automatic gains; they require planning, attention to deadlines and, above all, close technical follow up on developments still to come, such as the pending definition of the modulation of effects.