NFS-e: Release 1 of NT 009 Is Already in Testing — What Changes and What to Check by December 2026

NFS-e Enters New Testing Phase Ahead of December Deadline

The NFS-e Management Committee (CGNFS-e) took another step forward in the evolution of the national NFS-e layout. On October 20, 2026, the committee released, in a restricted production environment, release 1 of the changes set out in Technical Note No. 009, version 1.0 — the testing stage that precedes final implementation, now scheduled for December 1, 2026.

(cite index="23-1">The NFS-e Management Committee announced that three enhancements brought by Technical Note 009, version 1.0, are now available in the restricted production (testing) environment of the NFS-e, as part of the gradual rollout of changes to the document's layout. Municipalities and taxpayers can already access the environment and validate their issuing systems before the switchover.

The Three Changes Released for Testing

According to CGNFS-e documentation, release 1 brings three concrete enhancements to the NFS-e layout and API:

• Repositioning of CST and cClassTrib: (cite index="19-12">the two fields change position in the NFS-e XML, as set out in item 2.16 of NT 009.
• New taxable events in the API: (cite index="19-13">codes 99.02 to 99.04 are added to the issuance API, as provided for in NT 009 and NT 005.
• Creation of the vAjusteBC group: (cite index="17-8">formed by merging the vDedRed and gReeRepRes groups, as set out in item 2.3 of Technical Note No. 009, for adjustments to the IBS and CBS tax base.

Timeline: What Applies Today and What Changes in December

It is important to make clear to the tax and IT teams that, for now, nothing changes in day-to-day issuance. (cite index="20-7,20-8">Implementation in the production environment is scheduled for 12/01/2026, and the layout currently in production will remain in effect until 11/30/2026, as defined by Technical Note No. 004, Version 2.0. In other words: the testing environment exists for exactly this purpose — to test and adjust the issuing system or integration, and only afterward migrate.

It's worth emphasizing that this is not an isolated event. (cite index="20-13">Subsequent layout adjustments, starting with version 1.01 of NT 009, follow the same path: first restricted production, then implementation in production on 12/01/2026. And there's more to come: (cite index="26-6">Electronic Service Invoices for adjustment purposes, as well as specific events related to the Consumption Tax Reform, will be implemented in later stages, according to a specific schedule to be announced by the RFB.

Why This Matters for Tax, Accounting, and IT Teams

For those managing NFS-e issuance for a company or a client portfolio, this release signals that the final stretch of the year will bring a concentration of new technical validations, running in parallel with the already tight Tax Reform calendar (DeRE, the option for the hybrid Simples regime, the new DANFE layout, among others). We recommend:

• Checking with your issuing system provider whether the NFS-e restricted production environment is already being tested;
• Internally mapping who uses the CST, cClassTrib fields and the tax base adjustment groups in in-house integrations;
• Monitoring the publication of versions 1.01 and later of NT 009, which will follow the same testing process before December;
• Not treating the 12/01/2026 deadline as distant — the testing window exists precisely to avoid mass rejections at the switchover.

This content is for informational purposes only and does not replace guidance from your accounting firm or a tax specialist for decisions specific to your company.

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