Simples Nacional Annex III table
Annex III covers most Simples Nacional service providers, either because the Payroll Factor (payroll divided by revenue) is 28% or higher, or because the activity is on the list that always uses this annex regardless of payroll. This page opens the calculator locked to Annex III, with an example RBT12 in the 3rd bracket.
The nearly 2.5 percentage point gap between nominal and effective is exactly the deductible amount being spread across RBT12.
In the 1st bracket of any annex, the deductible amount is always zero, so the effective rate matches the nominal one exactly.
The nominal rate is only the formula's starting point, it represents the tax that would be owed if RBT12 sat exactly at that bracket's ceiling. For any RBT12 below the ceiling, the deductible amount lowers the result, so the real effective rate, computed as (RBT12 x nominal rate - deductible amount) / RBT12, is always lower than or equal to the nominal one. Applying the nominal rate directly, without subtracting the deductible amount, is the most common mistake in informal calculators and always overstates the tax.
No. Activities subject to the Payroll Factor test only fall under Annex III when payroll over the last 12 months is 28% or more of RBT12; below that, they fall under Annex V. Activities like travel agencies, gyms and schools always use Annex III regardless of payroll, and activities like construction and security guard services fall under Annex IV, never Annex III.
IRPJ, CSLL, COFINS, PIS/Pasep, CPP (employer social security) and ISS, all in a single bill, with allocation percentages that vary by bracket. Above the R$3.6 million RBT12 sub-cap, ISS leaves the DAS and is collected separately under the municipality's own rules.
(RBT12 R$ 720.000,00 × nominal rate 13.50% - deductible R$ 17.640,00) / RBT12 = effective rate of 11.05%.
At that revenue pace, the bracket should not change over the next 36 simulated months.
The whole calculation runs in your browser: RBT12, revenue, payroll and the chosen annex are never sent to a server.