Simples Decision 2027.
IBS/CBS inside or outside the DAS?

The September–October 2026 first-semester window

CGSN Resolution 194/2026 amended the historical timetable originally set by CGSN Resolution 186/2026. A company already in Simples may elect regular IBS/CBS assessment for January–June 2027 from September 1 through October 30, 2026. In a separate process, entry or return to Simples for 2027 may be requested through October 15; if the request is denied because of an impediment, that impediment may be cured through October 30. Either choice may be cancelled, on an irrevocable basis, from November 3 through December 20, 2026.

CGSN Resolution 190/2026 establishes an option or waiver period from March 1–31, 2027 for July–December 2027, with cancellation available through May 31, 2027. The decision is therefore made by semester, not once for the whole year.

Path A — Keep IBS/CBS inside the DAS

It keeps the unified payment in the DAS (Simples Nacional Collection Document), with an aggregate rate ranging from 4% to 33% depending on the activity annex and revenue bracket. Assessment remains simpler — one monthly slip and no separate IBS/CBS calculation — but invoicing and ERP processes still need to follow the applicable legal requirements and the evolving NT 2025.002 technical schedule.

The commercial point: the B2B customer gets a reduced IBS/CBS credit

When a customer buys from a Simples supplier that kept IBS/CBS inside the unified DAS, an eligible customer may still take an IBS/CBS credit — but a reduced one, limited to the amount of those taxes due under Simples, not the full regular-regime rate. This is the rule in Complementary Law 214/2025, Article 47, paragraph 9: the credit is smaller, not zero. (The full rate is not yet set in law — 26.5% is a trigger ceiling, not the rate in force — art. 475.)

Practical result: the same good or service may generate a larger credit when the Simples supplier assesses IBS/CBS outside the DAS than when those taxes remain inside it. The difference is the magnitude of the credit — limited under Article 47, paragraph 9, versus the full statutory credit — not whether the supplier remains in Simples. In a business purchasing decision, that differential can be decisive.

Who this path makes sense for

Path B — Assess IBS/CBS outside the DAS

The company stays in Simples for the other covered taxes, but begins to assess IBS and CBS separately — breaking out the credit on the invoice at the full rate (not yet set in law; 26.5% is a trigger ceiling, art. 475). This is an IBS/CBS election inside the Simples framework, not a move to Lucro Real or Lucro Presumido. An eligible B2B customer may take the full credit, preserving commercial competitiveness.

The operational costs of Path B

The company gains two new obligations:

1. Monthly assessment of IBS and CBS — separate from the Simples assessment, with its own bookkeeping
2. Collection outside the DAS — the company must follow the payment procedures applicable to IBS and CBS instead of assuming one unified DAS flow

In addition, there is an initial adaptation cost: the ERP must be configured to issue NF-e under the Reform (NT 2025.002) with IBS/CBS fields, the tax team must be trained in the new rules, and accounting processes must be reviewed.

Who this path makes sense for

• B2B companies selling to credit-eligible buyers — the customer may value the credit differential, which must be measured against the actual customer base
• Industries with long chains — the intermediary customer needs the credit to pass it on
• Technical service providers to large companies — buyers may compare the effective IBS/CBS credit available from each supplier
• Companies with material B2B exposure — the credit differential merits quantitative modeling; no fixed revenue percentage determines the answer

Decision matrix by profile

Recommended quantitative modeling

Before deciding, it is advisable to model two scenarios for the next 12 months (Jan-Dec 2027):

1. Inside-DAS scenario: current revenue × probability of retaining each B2B customer given the limited credit (versus a supplier offering the full credit) = projected revenue
2. Outside-DAS scenario: current revenue × additional operating cost of separate IBS/CBS assessment + ERP/tax adaptation cost = projected net margin

For a B2B company, the difference between the scenarios can materially affect annual operating margin. Its direction and magnitude depend on pricing, customer retention, available input credits and the additional compliance cost; they must be measured with the company’s own data.

Risks of the wrong decision

The cost of a wrong decision in the Simples Decision 2027 is asymmetric:

• Inside-DAS mismatch: the limited buyer credit may weaken B2B competitiveness when customers value the full credit (the magnitude varies by customer base)
• Outside-DAS mismatch: separate assessment and collection add operating cost without necessarily affecting revenue

In industrial supply chains and technical services, some buyers may factor the available IBS/CBS credit into supplier approval and purchasing. That does not require the supplier to leave Simples: the relevant comparison is between IBS/CBS inside the DAS (limited buyer credit) and outside the DAS (full statutory credit). The commercial effect must be measured against the actual customer base rather than assumed.

What NOT to do

1. Do not wait until an election window opens to start the analysis — modeling takes time when done correctly
2. Do not decide with accounting alone — the decision is strategic-commercial, not just tax
3. Do not copy a similar company’s decision — each customer base has a unique composition