Brazil's tax reform 2026: what changes in assessment (CBS and IBS)

2026 is the start year of Brazil's tax reform. Tax assessment begins to change, and accountants need to understand the schedule to avoid calculation errors. Here's the essential picture.

What begins in 2026

From 2026, CBS (federal Contribution on Goods and Services) and IBS (state and municipal Tax on Goods and Services) start to apply. 2026 is a test year: CBS is shown at 0.9% and IBS at 0.1%, but generally without actual collection — it lets companies and systems adapt.

The transition schedule (2026–2033)

Replacing PIS, COFINS, ICMS and ISS with the dual VAT (CBS + IBS) is gradual:

• 2026: CBS and IBS in a test phase (symbolic rates).
• 2027: CBS replaces PIS/COFINS; IBS starts to rise.
• 2029–2032: ICMS and ISS are phased down while IBS increases.
• 2033: the new model is fully in force.

In practice, for several years the old and new rules coexist. That's why the calculation must use the rates and rules valid in each period.

The risk: recalculating the past with the wrong rule

A common spreadsheet mistake is applying today's rule to an old period. In a transition that changes year by year, that produces incorrect amounts. The fix is to treat rule versions as immutable: each assessment keeps the rule that applied that month, and past recalculations stay correct even after the law changes.

How DocsSmart helps

DocsSmart's accounting module already knows the 2026–2033 schedule and shows the old rules and the reform side by side, so you can compare the impact per company. It assesses Simples, Presumido and Real, calculates ICMS-ST and DIFAL, and generates trial balance, P&L and balance sheet — always with auditable calculation memory.

See the accounting software for the tax reform page and test it with your client portfolio.