STF And STJ' Decisions Regarding ICMS Are The Focus Of This Tax Newsletter

• Published date: 09 October 2025
• Subject Matter: Litigation, Mediation & Arbitration, Tax, Trials & Appeals & Compensation, Tax Authorities
• Law Firm: Koury Lopes Advogados
• Author: Mr Felipe Omori, Matheus Barreto and Thaís Arantes

Among the tax law news from the past month are STF decisions on retroactive ICMS, habitual tax debtors, and STJ rulings on ICMS DIFAL

In this Tax Law newsletter, you will read about:

1. STF rules out retroactive ICMS collection on internal transfers
2. STF validates special regime against habitual ICMS debtors in Rio Grande do Sul
3. STF upholds the understanding on res judicata in tax matters in Themes 881 and 885
4. STF determines that the Selic rate applies to all disputes involving the Federal Treasury
5. STF maintains the unconstitutionality of ISS on contract manufacturing
6. STJ rules out the statute of limitations for writs of mandamus regarding periodic taxes
7. STJ affects repetitive appeal on inclusion of ICMS DIFAL in the PIS/COFINS tax base

1. STF rules out retroactive collection of ICMS on transfer between establishments of the same company

The Supreme Federal Court (STF) ruled that the modulation established in Declaratory Action of Constitutionality (ADC) No. 49 does not authorize states to retroactively collect ICMS on transfers of goods between establishments of the same company prior to 2024. The...