What changed on November 1
Resolução CGSN nº 191/2026 amended art. 59 of Resolução CGSN nº 140/2018, the rulebook of the Simples Nacional. Under the new § 1, an ME or EPP on the Simples that provides services requiring a service invoice must use the national-standard NFS-e, issued through the Emissor Nacional da NFS-e.
The date moved once along the way. Resolução CGSN nº 189/2026 had set the start for September 1, 2026; nº 191 revoked it and set November 1 instead.
The rule also covers a company whose Simples election is still pending, under administrative or judicial review, and a company that went over the sub-limit and can no longer pay ICMS and ISS through the Simples (art. 12 of Resolução CGSN nº 140/2018). For transactions subject only to ICMS, an ME or EPP may not issue this NFS-e.
What about the MEI? The resolution covers MEs and EPPs. Individual microentrepreneurs (MEI) have issued the NFS-e only through the national system since September 1, 2023, under Resolução CGSN nº 169/2022, so the Emissor Nacional is nothing new for them.
How to issue invoices now
The resolution allows two ways to use the Emissor Nacional: the web issuer, where you fill in and issue the invoice on the NFS-e Portal (nfse.gov.br), and an API integration, where your business software sends the invoice data straight to the national system.
An invoice issued this way is valid throughout Brazil, and city governments read the data through the Painel Municipal NFS-e and a shared data environment. The resolution does not cover each city's own procedures. If your city asks for a registration or an extra step, your accountant can confirm it with the city.
Before your next invoice, check these three things.
- Log in to the Emissor Nacional and check that your company details and the services you provide are correct;
- If business software issues your invoices, ask the provider whether it already sends the NFS-e to the Emissor Nacional by API;
- Issue your first invoice through the Emissor Nacional and review it with your accountant before sending it to the client.
What about IBS and CBS?
These are two separate rules, and the Receita Federal itself made a point of keeping them apart. Resolução CGSN nº 191/2026 says where the invoice is issued. The IBS and CBS rules, tied to Ato Conjunto RFB/CGIBS nº 4/2026, only take effect for Simples Nacional companies on January 1, 2027, when these taxes become part of the regime.
In practice, until December 31, 2026 a Simples company issues through the Emissor Nacional and follows the regime's current rules, without applying the IBS and CBS rules. From January 1, 2027, it stays on the Emissor Nacional and also reports IBS and CBS on the invoice in the cases the regulations set out.
Our advice is to make good use of these two months. If you reach December issuing smoothly through the Emissor Nacional, the only thing left for 2027 is the new fields.
Key dates
For companies on the Simples Nacional, these are the two dates.
| Starting | What applies |
|---|---|
| November 1, 2026 | National-standard NFS-e, issued through the Emissor Nacional, required for Simples Nacional MEs and EPPs (Resolução CGSN nº 191/2026). |
| January 1, 2027 | IBS and CBS rules for Simples Nacional companies, including the information on these taxes on the invoice where applicable (Ato Conjunto RFB/CGIBS nº 4/2026). |
The dates for companies under Lucro Presumido and Lucro Real, document by document, are in our article on IBS and CBS on invoices.
What Duox does
If your company is on the Simples and you're still unsure where to issue invoices, talk to Duox on WhatsApp. We'll check your Emissor Nacional access and your first invoices with you, and get the company ready for the 2027 IBS and CBS rules.
This article is general guidance, and every company's tax situation is its own.