Year-by-year estimate of how Brazil's consumption-tax reform (2026–2033) affects a business's tax burden, prices and margins.
The tool turns the transition rules of Constitutional Amendment 132/2023 and Complementary Law 214/2025 into a tested calculation engine. It compares the current system (PIS/Cofins, ICMS, ISS, IPI) with the new dual VAT (CBS and IBS) for each year of the transition.
Live demo: https://lucascampos-dev.github.io/simulador-ibs-cbs/
⚠️ Educational estimate, not tax advice. IBS/CBS reference rates will be set by the Federal Senate, and several points still depend on regulation. Results rely on simplifying assumptions, all documented below, and do not replace a professional analysis based on real company data.
The reform replaces five taxes with a non-cumulative, tax-exclusive ("por fora") dual VAT through an eight-year phase-in. Business owners need a simple answer to a hard question: what happens to my tax burden and my prices each year? This project answers it with a calculator that:
- cites its sources. Every legal parameter is mapped to the constitutional or statutory provision, or to the official estimate, it comes from (docs/fontes.md).
- labels what is not settled. Anything not yet regulated is an editable parameter marked as an assumption ("premissa").
- is tested. The engine is a pure ES module with 31 unit tests covering the transition schedule, rate reductions, regimes and invariants.
- has zero dependencies. It needs no build step, no CDN and no framework. The chart is hand-made SVG and the page deploys as-is on GitHub Pages.
- Inputs: revenue from goods and from services, purchases that generate credit, payroll (no credit), and current regime: Lucro Real (non-cumulative PIS/Cofins), Lucro Presumido (cumulative) or Simples Nacional (simplified model).
- Current taxes: effective ICMS, ISS and IPI rates, plus optional exclusion of ICMS from the PIS/Cofins base (STF Theme 69).
- Reform parameters: sector treatment (standard rate, 30% reduction, 60% reduction, zero rate) and editable CBS/IBS reference rates, with presets from official estimates.
- Advanced assumptions: effective credit on purchases, credit retention for zero-rated sales, IBS/CBS inside the ICMS/ISS base during the transition (a disputed point), and IPI kept for Manaus Free Trade Zone products.
- Outputs for 2026–2033:
- net tax burden, current system vs. reform, as an SVG stacked-bar chart with keyboard-accessible tooltips and a table
- effective rate on the price charged
- price change needed to keep the margin in R$
- profit impact if prices stay unchanged
- a plain-language explanation and context-aware warnings
- Export: CSV (
;-separated with decimal commas, opens correctly in Excel pt-BR) and a print-friendly view that includes a summary of the scenario's assumptions. - UX: responsive, light/dark themes, keyboard navigable, labelled inputs,
aria-liveresults, and a table alternative for the chart.
| Topic | Provision |
|---|---|
| 2026 test year: CBS 0.9%, IBS 0.1%, offset against PIS/Cofins or waived when filing obligations are met | EC 132/2023, ADCT art. 125; LC 214/2025, arts. 343, 346 and 348 |
| 2027: full CBS, PIS/Cofins abolished, IPI zeroed except Manaus Free Trade Zone (ZFM) products, Selective Tax starts | ADCT art. 126 |
| 2027–2028: IBS 0.05% state + 0.05% municipal; CBS reduced by 0.1 p.p. | ADCT art. 127 |
| 2029–2032: ICMS/ISS at 90%, 80%, 70%, 60% | ADCT art. 128 |
| 2033: ICMS and ISS abolished | ADCT art. 129 |
| Reference rates set by the Senate | ADCT art. 130 |
| Zero rate: National Basic Food Basket | LC 214/2025, art. 125 |
| 30% reduction: 18 regulated intellectual professions | LC 214/2025, art. 127 |
| 60% reduction: health, education, food, medicines and other listed items | LC 214/2025, art. 128 ff. |
| Simples Nacional option to pay IBS/CBS under the regular regime | LC 214/2025, art. 41 |
| ICMS/ISS excluded from the IBS/CBS base | LC 214/2025, art. 12, § 2 |
| Split payment (collection at financial settlement) | LC 214/2025, arts. 31–35 (concept only, not modelled) |
Default reference rates: CBS 9.21% and IBS 18.70% (total 27.91%), from CGIBS Resolution No. 14 of 29 July 2026. This is the latest official estimate with an IBS figure. The CBS value is implied (27.91 − 18.70). A second preset loads the initial Ministry of Finance (SERT) estimate: 8.8% + 17.7% = 26.5%.
Full source list with URLs and access dates: docs/fontes.md.
All amounts are annual. Rates are entered as percentages. t is the combined IBS + CBS rate for the year after any sector reduction.
ICMS = icms_eff × goods revenue
ISS = iss × services revenue
IPI = ipi_eff × goods revenue (added on top of price)
PIS/Cofins = 9.25% (Lucro Real) | 3.65% (Presumido) × (revenue − ICMS if excluded)
credit = 9.25% × purchases × share already creditable (Lucro Real only)
burden = ICMS + ISS + IPI + PIS/Cofins − credit
net value = revenue − ICMS − ISS − PIS/Cofins (sales net of consumption taxes)
result = net value − (purchases − credit) − payroll
Simples: burden = DAS rate × revenue
t_y = (CBS_y + IBS_y) × sector factor (1 | 0.7 | 0.4 | 0)
CBS_2027-28 = CBS_ref − 0.1 p.p.; IBS_2027-28 = 0.1%
IBS_2029-32 = IBS_ref × (1 − legacy factor) [assumption]
legacy factor: 1 (2026–28), 0.9, 0.8, 0.7, 0.6 (2029–32), 0 (2033)
credit = purchases × t_p / (1 + t_p) t_p = standard rate × credit %
IBS/CBS = t_y × N (base excludes ICMS/ISS)
ICMS/ISS = a × f × N / (1 − a × f) ("por dentro" at reduced rate)
price = N + ICMS + ISS + IPI + IBS/CBS
burden = ICMS + ISS + IPI + IBS/CBS − credit
The engine solves two scenarios. Both are linear in N, so each has a closed form:
- Keep margin. Choose the net value
Nthat keeps the result in R$ unchanged:N = result₀ + (purchases − credit) + payroll. The output is the resulting customer price and its change against today. - Keep price. Fix today's customer price, per goods and services segment, and compute
N = price₀ / multiplier. The output is the change in annual result.
The year 2026 is neutral by design, because test amounts are offset or waived.
Simples Nacional: "inside the DAS" keeps the DAS burden constant. "Outside" (regular IBS/CBS from 2027) removes the PIS/Cofins share from the DAS and phases out the ICMS/ISS share with the legacy factor. Full IBS/CBS then applies with credits: price = N(1+t) / (1 − d(1+t)).
- Reference rates are estimates. The Senate will set the official 2027 rates by 15 Dec 2026, after TCU review. If the estimate exceeds 26.5%, LC 214/2025 obliges the Executive to propose corrective measures, but this cap is not automatic.
- IBS rates in 2029–2032 are approximated as the reference rate times the complementary fraction of the ICMS/ISS reduction. The actual rates will be calibrated to replace lost revenue.
- Supplier prices: the gross price of purchases is held constant, and credit is the IBS/CBS embedded in it. Supplier repricing is not modelled.
- Effective ICMS/IPI rates are already net of credits. Interstate rate differences (DIFAL), ST, benefits and credit accumulation are not modelled.
- Not modelled: Selective Tax, specific regimes (fuel, financial services, real estate, cooperatives etc.), cashback, presumed credits, income taxes, the cash-flow effect of split payment, and reduced rates on purchases (approximate them with the effective credit % input).
- Simples Nacional is a deliberately simplified model based on the effective DAS rate and share-of-DAS inputs (defaults: Annex I, 1st bracket).
- Zero-rate credit retention is an editable assumption.
- Negative net burden means credits exceed debits: an accumulated credit balance eligible for refund, but not necessarily cash in the same year.
# serve the static site (ES modules need http://, not file://)
python3 -m http.server 8080 # or: npm start
# open http://localhost:8080Requires Node.js ≥ 18 and has no dependencies:
npm test # = node --testThe suite (tests/calc.test.js) covers:
- the transition schedule year by year
- the 30% / 60% / zero reductions
- PIS/Cofins in both regimes and the ICMS exclusion
- 2026 neutrality, PIS/Cofins and IPI extinction in 2027, and the ZFM exception
- the proportional ICMS in 2030 and the disputed IBS/CBS-in-ICMS-base option
- the keep-margin and keep-price invariants and the burden decomposition identity
- the Simples inside and outside options
- input validation, the plain-language explanation and the CSV format
index.html UI (Portuguese), GitHub Pages entry point
assets/styles.css Design tokens (navy + teal), responsive, dark mode, print
assets/favicon.svg
src/calc.js Pure calculation engine (ES module, no DOM)
src/chart.js Hand-made SVG chart with accessible tooltips
src/app.js Form ↔ engine ↔ rendering, CSV export, print
tests/calc.test.js node:test unit tests
docs/fontes.md Legal parameters, sources and access dates
Go to Settings → Pages → Deploy from a branch → main / root. No build step is needed; .nojekyll is included.
Simulador educacional da Reforma Tributária do Consumo. Informe as receitas de mercadorias e serviços, as compras que geram crédito, a folha, o regime atual (Lucro Real, Lucro Presumido ou Simples Nacional) e as alíquotas efetivas de ICMS, ISS e IPI. O simulador compara, ano a ano de 2026 a 2033, a carga atual com a carga sob IBS/CBS. Mostra também a alíquota efetiva, a variação de preço necessária para manter a margem e o efeito no resultado caso o preço seja mantido.
O cálculo segue o cronograma da EC 132/2023 (ADCT, arts. 125 a 130) e as regras da LC 214/2025:
- reduções de 30% e de 60% e alíquota zero
- opção do Simples por recolher IBS/CBS "por fora"
- base de cálculo sem ICMS/ISS
As alíquotas de referência padrão (CBS 9,21% e IBS 18,70%, total de 27,91%) vêm da Resolução CGIBS nº 14/2026 e podem ser editadas. É uma estimativa educacional, não consultoria tributária. Fontes completas estão em docs/fontes.md.
Built by Lucas Campos, freelance full-stack developer (WordPress, WooCommerce, Power Apps, Power BI). LinkedIn: https://www.linkedin.com/in/lucas-campos-1146abab
MIT © 2026 Lucas Campos