The IBS and CBS regulation: what changes and when

On 30 April 2026, the Brazilian Tax Reform stopped being only “what changes” and gained the “how”: Decree No. 12.955/2026, which regulates the CBS, and CGIBS Resolution No. 6/2026, which regulates the IBS, were published — two mirrored texts, with more than 600 articles each. For companies, the message is direct: the first operational milestone is 1 August 2026 — the first day of the fourth month after publication (art. 112) — when the single registration and the obligation to issue an electronic tax document with the IBS and CBS fields take effect. And there is a detail that changes planning: the regulations were born expressly provisional, in “version 1.0”, with a revision already dated for the following months. This guide unpacks what each front means for your company’s operations.

From “what changes” to “how it’s done”

Complementary Law 214/2025 said “what”: it created the IBS, the CBS and the Selective Tax and set the principles. The regulations descend to the “how” — and this is where company operations are effectively impacted. They are two extensive and largely mirrored texts: Joint Ordinance MF/CGIBS No. 7/2026 formalized the mirroring of Book I (provisions common to IBS and CBS), and each tax has its own provisions. Reading the two together — what is common and what is specific — is the first step of any serious adaptation.

Assisted assessment: the tax authority pre-fills the tax

This is the deepest change of tax culture. The taxpayer stops “building” the tax and starts adjusting an assessment pre-filled by the tax authority — by the Federal Revenue Service for the CBS, and by the Management Committee for the IBS — built from tax documents, debt-extinction information and the Declaration of Specific Regimes (DeRE). The balance becomes available on the 15th of the following month (or the 20th, for those who file the DeRE).

Two details change the game: the confirmation (or adjustment) has the effect of a debt confession, and silence within the deadline presumes the balance correct and constitutes the tax credit automatically. The correct classification of each item in the tax document becomes, in the Treasury’s own words, “the only concern” — the tax effort shifts from assessment to the quality of the data at the source (CST and cClassTrib on each invoice), and a framing error becomes tax over- or under-paid, or credit blocked for the client.

Three new tax documents

Beyond the IBS and CBS fields added to current documents, three new documents arise that ERPs and systems must support:

The mandatory-use dates of the new fields and of each new document are set by a joint act of the RFB/CGIBS, with a general milestone in August 2026 and specific deadlines, within a transition that runs to the end of 2032.

Credit refunds with deadlines — and why compliance became cash

In the current system, recovering a credit balance can take years. The regulation sets maximum analysis deadlines, with SELIC adjustment and automatic refund within 15 days if the tax authority does not respond; the deadline only pauses for an audit, limited to 360 days.

The message is direct: being in tax compliance stopped being a governance talking point and became a cash advantage — recovering a credit in 30 days, rather than 180, changes the working capital of any input-intensive operation.

Split payment: the detailing — and what has not yet come out

Collection at financial settlement was unpacked. The regulation maps twelve payment arrangements — from payment slips and Pix (in their variations) to TED, TEF, credit and debit cards, prepaid and vouchers — and provides for two procedures: the standard, in which the payment provider queries the RFB/CGIBS platform and collects the difference, and the simplified, with a preset percentage, aimed at B2C transactions and which does not generate credit to the acquirer for the segregated amount. When the payment method cannot segregate, there is the alternative of collection by the acquirer. Implementation is gradual: the first stage tends to be restricted to business-to-business (B2B) transactions, on an optional basis.

Economic groups: two blind spots

For companies organized in a group, the regulation left two points requiring immediate attention. The intercompany loan (mútuo) within the same group was left outside the specific regime for financial services — which affects the treatment of centralized treasury operations. And cost sharing among group companies was not regulated, pending a future joint act. Shared-services structures, operating holdings and shared cost centers should map this exposure before consolidating processes.

The timeline that matters

The point that changes planning: “version 1.0 → 2.0”

The regulations went through a public consultation via the Receita Atende platform, between 4 and 31 May 2026, and a revision — “version 2.0” — is expected about 90 to 100 days after publication, that is, around August 2026. In addition, several central points were left to joint acts not yet issued: the split-payment dates, the simplified-procedure percentages and cost sharing among group companies.

What your company should do now

• Adapt systems and registration to issue a tax document with IBS/CBS fields from 1 August 2026.
• Review the tax classification (CST and cClassTrib) of each product and service — it is the data that feeds the assisted assessment.
• Map credits and assess joining a compliance program (refund in 30 days, not 180).
• Map payment methods and begin the technical dialogue with gateways and acquirers for the split.
• For groups: map the exposure in intercompany loans and cost sharing.
• Build a regulatory-monitoring calendar that covers “version 2.0” and the pending joint acts.

How TaxUp supports

Reading the two regulations together is the starting point. The TaxUp team helps companies translate the 600-plus articles into an adaptation plan: credit mapping, tax-classification adjustment, integration between tax, IT, payment methods and treasury, attention to the blind spots of economic groups, and a calendar that tracks “version 2.0” and the joint acts. See also the complete guide to the Tax Reform.

Frequently asked questions

Sources: Decree No. 12.955/2026 and CGIBS Resolution No. 6/2026 (Planalto and CGIBS); Joint Ordinance MF/CGIBS No. 7/2026; Ministry of Finance and Federal Revenue Service — 2026 guidance; APET (Receita Atende public consultation, closed on 31/05/2026); LC 214/2025. Informational content, updated June 2026; dates, percentages and “version 2.0” depend on joint acts and are estimates; article numbering should be checked against the consolidated version — it does not replace an individualized analysis of each case.