The IBS/CBS regulation is now approved. The Countdown to compliance has started

With the publication of the regulation, the deadline provided for in the Joint Regulatory Act RFB/CGIBS No. 01/2025 (Federal Revenue Service/Steering Committee of the Goods and Services Tax) comes into force, which establishes that, as of August 1, 2026, all tax documents must contain the IBS and CBS fields.

This requirement is not merely formal. Failure to fill in properly will result in the automatic rejection of the tax invoice. In practical terms, this means a real risk of operational stoppage: impossibility of issuing e-Invoices (NF-e - Nota Fiscal Eletrônica), shipping cargo, releasing goods at ports and airports, and completing retail sales.

For companies with relevant operations, especially multinationals with complex integrations between ERP, satellite systems and tax issuance platforms, adaptation cannot be left to the short term.

The approval of the regulation inaugurates a period in which it will be necessary to review internal procedures and align teams, processes and systems. Among the most relevant points, we highlight:

• Mandatory completion of new tax fields: differentiated tax rates (CBS, state share of IBS and municipal share of IBS), Tax Classification Code (CT - Código de Tributação) and other specific attributes of operations.
• New calculation basis logic: the regulation clarifies that IBS does not replicate the structure of ICMS (State VAT - Imposto sobre Circulação de Mercadorias e Serviços), requiring deeper revisions in the calculation parameters.
• Consolidation of the financial credit system: the credit regime is comprehensive, but depends on a clear mapping of the nature of expenses and the framework of operations.
• Inspection and compliance rules: the regulation confirms the possibility of specific monitoring regimes for up to 360 days, reinforcing the need for robust tax governance.
• Harmonization between IBS and CBS: as they are "mirror" taxes, compliance must be thought of in an integrated way, avoiding divergences between federal and state-level requirements.

Based on the technical reading of the regulation and the experience accumulated in adaptation projects to the new model, we recommend that companies immediately start a structured plan with the following fronts:

1.  Adjustments to tax systems and ERP
   Technological updating is the most critical and, in many cases, the most time-consuming step. It is necessary:

   • review existing tax parameterizations;
   • implement new mandatory fields;
   • adjust calculation rules and calculation routines;
   • validate integrations with TMS (Transportation Management System), WMS (Warehouse Management System), payment systems, and e-commerce platforms;
   • carry out integrated tests with approval environments of the State Tax Authorities (SEFAZ - Secretarias de Fazenda).

2. b) Tax Registry and Tax Classification (CT) review
   The new CT will replace multiple state and federal classifications. To avoid rejections or undue credit:

   • review registrations of products, services and operations;
   • redefine internal classification rules;
   • update tables of NCM (Common Nomenclature of Mercosur - Nomenclatura Comum do Mercosul), CNAE (National Classification of Economic Activities - Classificação Nacional de Atividades Econômicas) and necessary correlations;
   • review codes used by suppliers and logistics partners.

3. Training of internal teams
   Successful implementation depends on conceptual mastery by all impacted areas. It is essential to enable:

   • tax and accounting teams;
   • supply chain, sales and purchasing teams;
   • technology professionals involved in ERP and automations;
   • legal and regulatory compliance teams.

4.  Communication with suppliers and customers
   IBS requires national standardization. Any non-standard point in the chain can generate serial rejections. We recommend:

   • align deadlines, data formats and validations with strategic suppliers;
   • review contracts that deal with transfers, prices and tax obligations;
   • establish formal communication channels for simultaneous adjustments.

Companies have just over three months between the publication of the regulation and the start of the obligation. This period is short when considering:

• adjustments of complex systems;
• large-scale tax registry reclassification;
• contractual revisions;
• tests with approval environments of the SEFAZ (State Tax Authorities);
• internal compliance validations.

Recent history shows that, even in states that started adaptations earlier, a significant portion of the invoices still did not have the IBS and CBS fields correctly filled in — which reinforces the urgency of broad and immediate adaptation.

The approval of the IBS regulation represents one of the most relevant regulatory movements since the enactment of Constitutional Amendment 132/2023 (EC 132/2023). From now on, there is no longer uncertainty about the regulatory framework that will govern the operationalization of the new taxes.

The legal environment is defined; it remains for companies to implement, test, and consolidate their compliance.

Our team is available to fully support all stages of this process, from the regulatory technical review to the operational implementation of the systems, ensuring legal certainty and continuity of operations.

Sincerely,

Vistra Brazil Team