Two resolutions, one goal: unlocking the transition from Simples Nacional to the new tax model
On August 4, 2026, the Simples Nacional Management Committee (CGSN) published two resolutions that change the timeline and rules of the simplified regime within the Consumption Tax Reform: CGSN Resolution No. 190/2026 and CGSN Resolution No. 191/2026, both published in the Federal Official Gazette on August 10. For those handling tax, accounting, or system parameterization at companies under Simples Nacional, both measures deserve immediate attention.
CGSN Resolution No. 191/2026: National NFS-e mandatory only starting November 1
The first relevant change is the postponement of the deadline for mandatory use of the National NFS-e Issuer by microenterprises (ME) and small businesses (EPP) that provide services subject to ISS. The Simples Nacional Management Committee published CGSN Resolution No. 191, of August 4, 2026, which changes the deadline for mandatory use of the National Electronic Service Invoice Issuer for taxpayers opting for Simples Nacional, and the requirement that would have taken effect on September 1, 2026 was postponed to November 1, 2026.
In practice, the new measure revokes CGSN Resolution No. 189, of April 23, 2026, which determined that all taxpayers opting for Simples Nacional should issue the Electronic Service Invoice through the National Issuer starting September 1. Until then, each company continues issuing invoices through the municipal system or the proprietary solution it already uses — as reinforced by the City of Guarulhos when it advised that, until October 31, 2026, Simples Nacional taxpayers must continue issuing NFS-e in the current version of the municipal system.
Starting November 1, issuance will become mandatory through the National Issuer, using one of the two provided methods: the web issuer or the communication service via Application Programming Interface (API). For accounting firms and IT departments that were already migrating processes, the message is clear: the postponement does not eliminate the obligation, it only provides two more months for API integration testing, layout certification, and team training. The change requires attention from taxpayers and, especially, from accounting firms and system developers, since companies that currently use municipal systems or proprietary solutions will need to be prepared for the new system by the time the rule takes effect.
CGSN Resolution No. 190/2026: IBS and CBS officially become part of Simples
On the same day, CGSN published Resolution No. 190/2026, which amends Simples Nacional Resolution No. 140/2018 to incorporate IBS and CBS into the regime. The measure formally includes the two new taxes among those collected in a unified manner under Simples and redefines concepts that directly impact companies' classification.
Among the most sensitive points for those handling payroll, revenue, and tax calculation:
- Tips not passed on, royalties, rents, interest, and fines now become part of gross revenue; income from financial investments, IBS/CBS under the regular regime, and tips fully passed on are excluded.
- Revenue is now defined by the issuance of a tax document, including in sales for future delivery and advance payments.
- The general gross revenue limit for Simples Nacional remains at R$4,800,000.00, but a sublimit of R$3.6 million was maintained for ICMS, ISS, and IBS in the domestic market and exports.
The resolution also confirms an important option for those under Simples: taxpayers opting for Simples Nacional may choose to calculate and pay IBS and CBS under the regular regime, in which case these taxes are no longer collected under the unified Simples regime. This decision requires a comparative simulation of the tax burden, since under the regular regime the company can claim IBS/CBS credits along the chain — something that does not happen the same way within Simples.
Decision window: September is the key month
For the six-month period starting in January 2027, the option for the regular IBS/CBS regime must be made on the Simples Nacional Portal between September 1 and 30, 2026, and may be canceled until November 30, 2026. This is the same September window used for the annual 2027 Simples Nacional election, which reinforces the importance of aligning the company's tax calendar with that of the accounting firm in the coming weeks.
What to do now
For companies under Simples and for those who serve them, the practical recommendation is: continue issuing NFS-e through the municipal system normally until October 31, but already begin integration testing with the National Issuer (web or API) before the deadline becomes mandatory; and, in parallel, evaluate with the accounting team whether it is worth migrating IBS/CBS calculation to the regular regime starting in 2027, since the September decision is practically irrevocable until November.
This content is for informational purposes only and does not replace guidance from your accounting firm, which should assess the company's specific classification in light of CGSN Resolutions No. 190 and 191/2026.
If your company needs to integrate Simples Nacional tax invoicing with an ERP ready for the upcoming Tax Reform changes, talk to Edoo.
CGSN No. 190 and 191/2026: National NFS-e under Simples Nacional Postponed to November, and IBS/CBS Added to the Regime's Rules