After months of anticipation, the IBS Management Committee published, on April 30, 2026, Resolution CGIBS No. 6/2026, regulating the Tax on Goods and Services in 617 articles. Issued in parallel with Decree No. 12.955/2026, which addresses the CBS, the text contains mirrored provisions for the common portion of the two taxes. It is the most important operational milestone of the consumption-tax reform since the enactment of LC 214/2025, and it combines concrete progress, relevant tightening and gaps that demand immediate attention from companies.
The operational starting point of the new system is the split payment. The mechanism requires IBS and CBS to be segregated and collected directly by payment service providers at the moment of financial settlement, without passing through the supplier's cash flow. For transactions in which the buyer is not a taxpayer under the regular regime — typically B2C transactions — there is also a simplified split payment, with withholding calculated using pre-established fixed percentages instead of real-time consultation as in the standard procedure. The option is irrevocable during the assessment period, and excess amounts must be returned to the supplier within three business days. There is, however, a point to watch: the Regulation allows financial institutions to escape penalties by claiming errors in information provided by the supplier itself. Split payment promises collection efficiency but requires robust technological integration and rigorous data quality.
For the incentivized industry in the Manaus Free Trade Zone, the Regulation brings a significant and very practical gain: in transactions destined for the ZFM, the originator of the transaction may apply, at the time of financial settlement, the presumed-credit percentages for IBS — 55% for final consumer goods, 75% for capital goods and 90.25% for intermediate goods, with enhanced credits for certain products. In addition, Decree No. 12.955/2026 establishes a presumed CBS credit of 6% of the transaction value for products under the differentiated tax regime provided in Complementary Law No. 214/2025, or 2% in other cases, calculated on the value recorded in a valid tax document.
This means that the split payment now respects the incentivized-industry benefit at the source, avoiding having the company finance the IBS in the interval between withholding and assessment — which, without this provision, would gut much of the incentive. The Regulation also consolidates the IBS suspension on imports by the incentivized industry, the zero-rate for operations originated outside the ZFM and destined for an authorized taxpayer, and the presumed-credit system, in line with LC 214/2025.
Perhaps the most sensitive point of the new text is the expansion of buyer liability: a buyer may be charged for debts of irregular suppliers. Combined with the requirement of proof of effective collection by the supplier in order to use credits, and with the possibility of cumulative application of penalties for a single inconsistent transaction, this shifts much of the supply-chain tax risk onto the buyer. In practice, the tax regularity of third parties becomes a condition for maintaining one's own credits and for legal certainty — which requires an immediate review of supplier onboarding and contract-management routines.
In counterbalance to this tightening, the Regulation delivers a relevant benefit for compliant taxpayers: priority refund of IBS credit balances, with differentiated deadlines based on compliance profile:
- Up to 30 days for taxpayers enrolled in compliance programs recognized by CGIBS and RFB;
- Up to 60 days for credit requests related to fixed assets and for amounts up to 150% of the monthly average of the difference between credits and debits (article 40 of LC 214/2025); and
- Up to 180 days in other cases.
If no manifestation is made within the deadline, the refund is automatic, adjusted by the Selic rate. This is a structural advance compared to current reality, where PIS/Cofins and ICMS refund requests frequently drag on for years. Commentators caution, however, about the distance between deciding and paying: predictability will depend on the operational capacity of the authorities to meet the deadlines. For exporters, companies in zero-rate chains or in intensive investment cycles, joining compliance programs tends to become a key piece in financial management.
Despite the effort at uniformity, the Regulation failed to address points long awaited by the market. The most relevant is cost sharing: LC 214/2025 did not expressly carve out cost-sharing agreements within economic groups from IBS and CBS, and the Regulation maintained that gap — especially regarding the operationalization of credit for taxpayers actually bearing the economic burden. Because the legal concept of consideration-bearing supply is broad and independent of profit margin or legal form, the reimbursements typical of these arrangements may be taxed. The absence of a specific rule may reproduce, in the dual VAT, the litigation historically seen in PIS/Cofins and ISS on this topic.
Equally without clear definition are the concept of "residential property" for the specific real-estate regime and the operational detail of the Consumer Transaction Registry, essential infrastructure for the full functioning of split payment — which depends on additional technical rules yet to be issued.
For the most part, the Regulation faithfully follows LC 214/2025 and performs interpretive and operational functions. There are, however, tightening measures that in practice expand the burden on taxpayers: the expanded joint liability of buyers; the practical linkage of credit to proof of supplier collection, which narrows the non-cumulativity promised by the reform's constitutional amendment; and cumulative application of penalties for a single inconsistent transaction.
On the calendar, August 2026 is the first critical date: starting on the 1st, filling out the IBS and CBS fields on tax documents becomes mandatory for taxpayers under the Real Profit and Presumed Profit regimes, with a 1% penalty on transaction value for non-compliance with ancillary obligations. In September, the national-standard NFS-e becomes mandatory for microenterprises and small businesses opting into Simples Nacional that provide services. The same month also concentrates the final window to opt for Hybrid Simples — a regime that allows IBS and CBS to be collected outside the DAS, generating full credit for corporate clients — for application starting in 2027.
The Regulation is a necessary technical advance, but far from closing the discussion. The text combines relevant tightening with concrete progress, such as the application of ZFM incentive percentages at the moment of payment and priority refunds for compliant taxpayers. Gray areas remain on sensitive points, such as cost sharing and the operational detail of the transaction-registry system, which will require attention from tax departments. The calendar is tightening: August inaugurates the era of penalties; September brings the mandatory national NFS-e for Simples. Taxpayers have until 05/31/2026 to send suggestions via Receita Atende — a short but strategic window, especially because a version 2.0 of the regulation is already expected 90 to 100 days after publication.