Overview
- The TCU plenary proposed an 11.3% reference alíquota for the Contribuição Social sobre Bens e Serviços and a 44.2% reduction for public procurement in a decision delivered on Wednesday, October 28.
- The reference rate is meant to preserve revenue now raised by PIS and Cofins and was derived from a confidential calculation model that Receita Federal gave the TCU on September 14 without numerical estimates.
- After the TCU sends its number to the Senate, the upper house has until December 15 to approve a different rate by resolution and any later change takes effect in the second month after approval.
- The government ran a 2026 transition year with mandatory IBS/CBS fields in electronic invoices from August 1 and penalties for reporting errors start in 2027, with annual recalculations of the reference rate through the 2033 transition end.
- The 2027 budget projects R$636.8 billion from the CBS, while non‑official technical references put combined CBS+IBS rates above the legal 26.5% cap for 2033, a gap that could force executive corrective proposals if future projections show the ceiling will be breached.