Brazil Consumption Tax Reform · Transition Regime Determination
Decides which tax regime, rates, and charge status apply to a Brazilian transaction across the 2026-2033 consumption tax transition.
Overview
For any taxable event date from 2026 through 2033 and beyond, the package places the transaction in the correct transition stage and works out which of IBS, CBS, ICMS, ISS, PIS, Cofins, IPI, and the Selective Tax are chargeable, at what rate, and on what proportion — feeding directly into invoicing and tax calculation.
The determination is grounded in Brazil's constitutional transitional provisions (ADCT arts. 125-133) and Complementary Law 214/2025, covering the full statutory timetable from the 2026 test year through the 2029-2032 ICMS/ISS phase-down to the new model taking full effect in 2033; rates that Brazilian law leaves to a future Senate resolution or to state and municipal legislation are explicitly out of scope and are requested rather than guessed.
In practice it handles cases such as: a transaction on the last day of 2026 computing cleanly against fully legislated rates; the very next day, 1 January 2027, flipping to blocked because the CBS rate becomes a Senate reference rate no source fixes; a reduced-rate fuel sale where the fuel carve-out zeroes the CBS reduction while the IBS rate still scales proportionally; a 2032 sale correctly measuring the ICMS phase-down against the rate in force on 31 December 2028 rather than the rate at sale; and a Zona Franca de Manaus product still carrying preserved IPI rates in 2033, long after ICMS and ISS have been extinguished.
Where a needed rate — a Senate reference rate, a state or municipal legislated ICMS/ISS rate, or a reduced-rate proportion — has not been supplied, the package marks the case as blocked and names exactly which figure is missing, rather than estimating it.
Every case returns a structured verdict — transition stage, per-tax charge status, applied rates, and reason codes for anything still outstanding — ready to drop into a billing or tax-determination workflow.
What it decides
Try it — live sandbox
Build a case and run it against the publisher's live production release — the exact rules a subscriber calls. Run the same case twice and the answer is identical: no LLM in the loop.
Run a case to see the deterministic decision — tags, routes, reasons, evidence, and facts. Same case in, same answer out, every time.
Integrate — two ways
Call it directly over HTTP, or connect your coding agent over MCP. Same decision, same metering, either way.
One authenticated POST — the same deterministic, metered evaluation the sandbox runs, no LLM in the loop.
# Request shape only. Replace sert_mk_YOUR_KEY and send every field from the Inputs contract above.
curl -X POST https://api.sertainly.ai/api/marketplace/v1/packages/transition_regime_determination/evaluate \
-H "Authorization: Bearer sert_mk_YOUR_KEY" \
-H "content-type: application/json" \
-d '{ "case": { "taxable_event_date": "example", "transition_year": 1, "is_simples_nacional_optant": true } }'