Simples Nacional in the tax reform.
The two options of the opting company, the credit exclusion effect and the September 2026 decision.

What changes for the Simples Nacional in the reform

The Simples Nacional lives on in the tax reform — and it remains the regime of most Brazilian companies. What LC 214/2025 does is not to abolish the Simples: it is to fit the IBS and the CBS — the two taxes that replace PIS, Cofins, IPI, ICMS and ISS — inside it, and, in doing so, to create a regime decision that did not exist before. The rule that anchors everything is art. 41 of LC 214/2025: under §1, whoever does not opt for the Simples or the MEI falls under the regular regime; under §2, “taxpayers opting for the Simples Nacional or the MEI remain subject to the rules of those regimes” — that is, by default the opting company keeps paying IBS and CBS within the DAS, the same single document through which it already pays its other taxes.

So far, nothing dramatic: the Simples remains a unified, simplified regime. The turn is that the same LC 214 opens, in art. 41, §3, a second door: the opting company “may exercise the option to assess and pay the IBS and the CBS under the regular regime”. Whoever takes this door removes only the IBS and the CBS from the DAS and moves them to the debit-and-credit mechanics of the Dual VAT — while staying in the Simples for IRPJ, CSLL, the employer contribution and the remaining taxes. It is what the market has nicknamed the hybrid Simples. The same faculty was inserted into the Simples Statute: LC 214 added to art. 13 of LC 123/2006 the provision that “the Simples Nacional opting company is allowed to assess and pay the IBS and the CBS under the regular regime” — a provision that entered as §9 and was renumbered to §10 by LC 227/2026, which adjusted the wording.

Why this choice matters so much

If the difference were only in the form of payment, it would not be worth an article. But it touches the heart of the reform, which is full non-cumulativity: under the Dual VAT, each link of the chain takes credit for the tax paid by the previous link. The point — developed in the following sections — is that the way the opting company pays IBS/CBS defines how much credit it transfers to the next link. Staying in the DAS transfers little; migrating to the regular regime transfers the full credit. In an economy where, according to a study by the IBPT (X-Ray of the Simples Nacional in 2025), more than 70% of Simples companies operate B2B — selling to other companies, not to the final consumer —, this mechanics ceases to be an accounting detail and becomes a strategic competitiveness decision.

The two options: stay in the DAS or migrate to the hybrid regular regime

Set side by side, the two options of art. 41 draw two very different regimes of IBS/CBS coexisting within the same Simples. It is worth unpacking each one before deciding.

Option 1 — Stay in the DAS (the “pure” Simples)

This is the default path, what happens if the company does nothing. The IBS and the CBS keep being paid within the DAS, together with the remaining taxes, under the simplified logic of the Simples: a single rate on the gross revenue, according to the bracket and the annex. The advantages are the usual ones — less bureaucracy, fewer ancillary obligations, a generally lower burden on final consumption. The counterpart, now made explicit by the reform, is in the credit: under art. 47, §9, I, the opting company that pays via the DAS takes no credit for the IBS/CBS on its own acquisitions, and the credit it transfers to the regular-regime customer is limited to the amount embedded in the Simples. It is the ideal scenario for whoever sells to the final consumer (B2C), where the customer takes no credit anyway.

Option 2 — The hybrid Simples (IBS/CBS under the regular regime)

Here the opting company exercises the option of art. 41, §3: it removes the IBS and the CBS from the DAS and moves to assess them under the full debit-and-credit mechanics, like any regular-regime taxpayer. LC 214 is express in referring the procedure to LC 123 (art. 41, §4: “the option... shall be exercised under the terms of Complementary Law No. 123”). The gain is decisive for the B2B profile: the company now states IBS/CBS at the full reference rate on the invoice and generates full credit to the acquirer, the same as a supplier under the Actual or Presumed Profit — and, as a regular-regime taxpayer for these two taxes, it also comes to take credit on its own purchases. The cost is the other side of the coin: more compliance (assessment, bookkeeping, IBS/CBS obligations outside the Simples) and taking on the full mechanics of these taxes, with only the remaining taxes left in the DAS.

The exclusion effect: why whoever buys from the Simples takes less credit

This is the core of the whole discussion — and the reason why the Simples in the reform matters so much both to whoever is an opting company and to whoever buys from one. The rule is in art. 47, §9 of LC 214/2025, which deals with the case where “the payment of the IBS and the CBS is made through the Simples Nacional, where the option for the regular regime is not exercised”. In that scenario, the law establishes two consequences:

• Item I — “the appropriation of IBS and CBS credits by the Simples Nacional opting company shall not be allowed”. The DAS supplier takes no credit for the tax it paid on its own purchases.
• Item II — to the regular-regime acquirer “the appropriation of credits... in an amount equivalent to that owed through that regime shall be allowed”. The customer does take credit — but only what was actually embedded in the Simples, not the full rate.

Debunking the myth: buying from the Simples “generates no credit”?

The idea circulates that acquiring from a Simples opting company gives no right to any credit at all. That is false. Art. 47, §9, II is clear: it does generate credit — but reduced. How much? The calculation comes from the LC 123 side: art. 23, §2 (wording of LC 227/2026) provides that the credit rate “shall correspond to the percentages of ICMS, IBS and CBS set out in Annexes I to V... for the gross-revenue bracket to which the micro or small enterprise is subject”. In other words: the credit passed on is the share of IBS/CBS embedded in the Simples percentage — typically much smaller than the Dual VAT reference rate. For scale, FecomercioSP estimates that, where today the Simples transfers about 9.25% of PIS/Cofins, under the new model it would pass on around 7% of IBS/CBS — figures from the entity, not fixed legal amounts, but which illustrate the direction of the movement.

What this does to the B2B supplier

The consequence is a competitiveness asymmetry. Since, under the Dual VAT, the regular-regime acquirer only takes full credit by buying from whoever states the full tax, the doctrine (ConJur) points out that regular-regime taxpayers will tend to transact preferentially among themselves — or with hybrid-Simples suppliers — precisely for the full credit. Sebrae (Edgard Fernandes, Competitiveness Analyst at Sebrae Nacional) sums it up: “if the company is a general-regime taxpayer or an opting company under the hybrid Simples Nacional regime, it tends to acquire inputs from companies under the hybrid Simples Nacional to take advantage of credits”. The effect is asymmetric: in B2C the Simples in the DAS remains advantageous; in B2B it can become a disadvantage, because the DAS supplier delivers less credit to the customer than a regular-regime competitor.

For the supplier: should I opt for the regular regime?

If you are a Simples opting company, the question that sums up this section is direct: is it worth migrating IBS/CBS to the regular regime — or even rethinking the Simples — because of the reform? The honest answer is that it depends on your customer profile, and the decision resolves itself in a simple tree.

The question that decides almost everything: who do you sell to?

If your customer base is predominantly B2C — final consumers, who take no credit —, the exclusion effect does not reach you: your customers lose nothing by your being in the DAS, and migrating would only add compliance and burden. Staying in the DAS tends to be the right choice. If, on the contrary, you are B2B — selling to industries, wholesalers, retailers, Actual/Presumed Profit companies —, your customers take credit, and a supplier that delivers reduced credit is, at the margin, a more expensive supplier. Here the migration to the hybrid Simples enters the calculation, so as not to lose a customer to a competitor that generates full credit. It is no laboratory hypothesis: according to the IBPT, more than 70% of Simples companies are B2B, with concentrations such as 84.6% in apparel (which supply retailers) and 62.3% in logistics/cargo transport (which serve industries).

The pros and cons of migrating

The lock-in of art. 41, §5 — the trap before deciding

There is a detail that changes the calculation and often goes unnoticed. Art. 41, §5 of LC 214/2025 bars the Simples taxpayer from “withdrawing from the regular regime of the IBS and the CBS if it has received a refund of credits of those taxes in the current or previous calendar year” (§6 extends the rule to the other options). Translating: whoever migrates to the regular regime and comes to request and receive a credit refund is locked in — it cannot return to the unified regime in the current year nor in the previous one. Migration, therefore, is not a revolving door: once a refund is requested, there is a lock-in. That is why the decision needs projection beforehand, not regret afterwards.

The window: September 2026, half-yearly and irreversible

The choice has a date and rules of its own, set out in art. 13, §10 of LC 123/2006 (wording of LC 227/2026): the option “shall be exercised for the half-years beginning in January and July of each year, being irreversible for each of those periods, and shall be exercised in the months of September and March immediately preceding each half-year”. In other words: a half-yearly option, irreversible per half-year. (The original wording of LC 214 said “September and April”; LC 227/2026 set “September and March”.) For the 1st half of 2027 — the start of the IBS/CBS charge —, the communication takes place in September 2026, and Resolution CGSN No. 186/2026 (of 09/04/2026) set the window at 1 to 30 September 2026, through the Simples Nacional portal. After that, the option follows the half-yearly calendar. The decision, therefore, is immediate: whoever wants to enter (or not) the hybrid in 2027 decides in September 2026. This cluster goes deeper into the topic in the Simples decision for 2027.

For the buyer: how to qualify the supplier base and not lose credit

Flip the coin. If you are a regular-regime company — Actual or Presumed Profit — that buys from Simples suppliers, the exclusion effect is your problem too, because it is your IBS/CBS credit that shrinks when the supplier is in the DAS. And it is no niche problem: with more than 70% of the Simples operating B2B, it is almost certain that a relevant share of your supplier chain is an opting company. Ignoring this is to accept, without calculation, a silent loss of credit as from 2027.

Step 1 — Map the base by regime

The first move is to know who you buy from. Segment the supplier base into three groups, because the credit you take is different in each: (a) Simples in the DAS — reduced credit, limited to what is embedded in the Simples (art. 47, §9, II); (b) hybrid Simples — full credit, full tax on the invoice (art. 41, §3); (c) Presumed/Actual Profit — full credit, standard regular regime. Group (a) is where the risk lives: for the same input, at the same price, you take less credit buying from a DAS supplier than from a hybrid one or a regular-regime one.

Step 2 — Qualify and renegotiate, not simply cut

Once group (a) is found, the instinctive reaction — to swap every Simples supplier for a regular-regime one — is usually hasty. Credit is not the only variable: price, quality, lead time and the long-term relationship still weigh, and a DAS supplier with a better price can offset the smaller credit. The right work is one of qualification and renegotiation: (i) project, supplier by supplier, the effective IBS/CBS credit in 2027; (ii) talk with the strategic Simples suppliers about the possibility of opting for the hybrid (which benefits both); (iii) reprice contracts considering the real credit, not the face price. It is a decision of supply-chain management and tax planning, not a blind cut.

The case law: what exists (and what does not yet exist)

Here one must be rigorous and honest, because a lot of misinformation circulates. There is no case law on IBS/CBS and the Simples Nacional. And there could not be: they are new taxes, created by LC 214/2025, in a trial phase in 2026 and with an effective charge only as from 2027 — Simples opting companies do not even state IBS/CBS before 2027 (LC 214 itself, in art. 348, III, “c”, exempts them from the CBS and the IBS in 2026). Hence, there is not a single ruling from the STF, the STJ or the CARF judging the merits of the IBS/CBS credit on a purchase from a Simples opting company. Any content that claims otherwise is fabricating precedent. Every analysis available today — including this one — is normative and prospective: it interprets the law and the doctrine (ConJur), not rulings.

What the current system has already settled — as an analogy, not as precedent

What exists, and serves as a bridge from the known to the new, is the case law on the non-cumulativity of the current taxes — which helps to understand the logic, without being precedent for IBS/CBS:

• PIS/Cofins — the acquirer’s credit on a purchase from the Simples: it was released administratively by RFB Interpretative Declaratory Act No. 15, of 26/09/2007, which confirmed the right of the actual-profit (non-cumulative) acquirer to take credit of the contributions on goods and services bought from a Simples opting company.
• Concept of input — Theme 779/STJ: in REsp 1,221,170/PR, 1st Panel, Reporting Justice Napoleão Nunes Maia Filho, judged on 22/02/2018, the STJ held that an input is the good or service assessed by the criteria of essentiality or relevance to the activity — the leading case that underpins the PIS/Cofins credit on inputs, including those bought from the Simples. It is worth reviewing the financial credit in the reform to see how the concept evolves under the Dual VAT.
• ICMS — credit on a purchase from the Simples: governed by art. 23, §§1 to 6 of LC 123/2006 itself and by Resolution CGSN No. 140/2018 (credit of the ICMS stated on the opting company’s document, limited to the annex rate). It is a predominantly normative/administrative topic — not an STJ leading case.

These are references from the current model. They help to intuit how the IBS/CBS should operate — but they cannot be presented as a decision on IBS/CBS.

The open constitutional front

There is, indeed, an inaugural constitutional litigation on the reform — but none on the IBS/CBS credit x Simples. What touches the Simples is ADI 7917/DF, filed by the Federal Council of the OAB (Reporting Justice Kássio Nunes Marques), which discusses the taxation of income tax on dividends/profits of opting companies (Law 15,270/2025) — the interlocutory injunction denied by the reporting justice —, a tangential matter, of income tax, not of IBS/CBS credit. And there is a block of ADIs in the context of the reform (EC 132/2023 and LC 214/2025) — ADIs 7779, 7790 and 7963 —, on benefits for persons with disabilities/autistic persons in vehicles and the refining of petroleum in the Manaus Free Trade Zone: they map the inaugural litigation of the reform, but do not judge the Simples credit. In a related matter on pesticides, ADI 7755 (Green Party) — which challenged the rate reduction, rather than defending it — was judged unfounded by the STF on 18/12/2025, keeping the incentive in place. In short: the ground is new, and the decision of the opting company and of the buyer is, today, one of management — not of litigation.

The market numbers: why this affects almost the whole chain

The reason why this discussion is not academic lies in the scale of the Simples. It is the predominant regime in Brazil: about 22 million active CNPJs were Simples opting companies in 2024 (Federal Revenue Service), of which about 13 million are MEIs (Business Map / Sebrae, 2025). For scale of the universe, the official Business Map recorded 24,213,445 active companies in the 2nd four-month period of 2025, of which 93.8% are micro or small-sized. Translating: when one speaks of the Simples in the reform, one speaks of almost the entire business base of the country — and, by extension, of almost the whole supply chain.

The economic participation reinforces the point. Micro and small enterprises — a universe that is mostly Simples — account for about 30% of Brazil’s GDP (Sebrae series, the most solid figure) and, according to Sebrae and FecomercioSP, for about 96% of the companies opened in 2025 and for a significant share of the jobs created. (Employment statistics vary by cut and source — we attribute them to Sebrae/FecomercioSP and use “about” deliberately.)

The figure that changes the reading: the Simples is B2B

The most relevant figure for the reform comes from the IBPT: in a study released on 28/08/2025 (X-Ray of the Simples Nacional in 2025, Carlos Pinto), more than 70% of Simples companies operate in the B2B model — they do not sell to the final consumer. It is exactly the profile most exposed to the credit exclusion effect, because their customers take credit. FecomercioSP, along the same lines, systematized “3 points that harm Simples companies in the reform”: (1) incomplete non-cumulativity — the opting company takes no credit on inputs and the credit passed on is limited; (2) reduction of the credit passed on; (3) a greater burden for whoever migrates to the full regime.

The decision calendar: September 2026, irreversible

Gathering the dates scattered throughout the text, the calendar of the Simples decision in the reform is this — and it is short. The IBS/CBS charge begins in 2027; 2026 is a trial year, with Simples opting companies exempt from IBS/CBS (art. 348, III, “c”). The first regime decision, therefore, must be taken beforehand — in the window of 1 to 30 September 2026 (Resolution CGSN No. 186/2026, of 09/04/2026), to apply in the 1st half of 2027. After that, the option follows the half-yearly pace of art. 13, §10 of LC 123 (communication in September and March), always irreversible for the chosen half-year.

How to decide the Simples regime in the reform

Gathering what we have seen, the supplier’s decision is organized into a few verifiable steps — the same roadmap that structures the TaxUp team’s advisory:

1. Map your customer mix (B2B vs B2C). Measure what fraction of the turnover comes from customers that take credit for IBS/CBS (regular-regime companies) and what fraction comes from the final consumer. It is the figure that dominates the decision.
2. Project the credit you transfer today vs under the hybrid. Estimate the reduced credit that goes out in the DAS (annex percentage) against the full credit of the regular regime — and how much that weighs in your customer’s purchase decision.
3. Calculate the burden and compliance cost of the hybrid. Add the IBS/CBS burden under the full mechanics and the cost of the new ancillary obligations, discounting the credit you would come to take on your own purchases.
4. Consider the lock-in before any refund. Remember that requesting a refund locks the exit (art. 41, §5); migration is a medium-term decision, not a reversible test.
5. Decide and communicate in the window. Register (or not) the option for the regular regime between 1 and 30 September 2026, through the Simples portal, to apply in 2027 — the option is irreversible within the half-year.

How the firm acts — at both ends of the chain

For the opting supplier — the regime decision

The TaxUp team conducts the decision diagnosis of the opting company we saw in section 8: measurement of the B2B vs B2C customer mix, projection of the credit transferred in the DAS against the hybrid, calculation of the burden and the compliance of the full mechanics and simulation of the impact on the commercial relationship. The output is a reasoned recommendation — stay in the DAS or migrate to the regular regime — with an express warning about the lock-in of art. 41, §5 and the schedule of the September 2026 window, so that the choice is made with projection, not in the scare of the deadline.

For the regular-regime buyer — qualifying the base

For the Actual or Presumed Profit company that buys from the Simples, the work is one of chain and credit management: mapping of the supplier base by regime (DAS, hybrid, regular regime), projection of the IBS/CBS credit effectively usable in each scenario and support for the commercial renegotiation — including the dialogue with strategic Simples suppliers about the option for the hybrid. The goal is not to lose credit along the chain without cutting suppliers by reflex, integrating the decision into the company’s tax planning.

Litigation and monitoring — new ground

As there is no case law on IBS/CBS x Simples, the work today is one of advisory and prevention, not of settled litigation. The firm monitors the CGSN regulation, the developments of LC 227/2026 and the ongoing constitutional litigation (the reform ADIs), and prepares the company for the controversies that will arise as from 2027 — from the sizing of the reduced credit to the eventual technical defence before the tax authority and the CARF. The Tax Reform pillar gathers the neighbouring parts of this transition — from IBS and CBS to split payment, the impact on companies and LC 214/2025.