Tax reform: advances and adjustments to keep on the radar in May

Federal Revenue Service and IBS Steering Committee extend deadline for submission of suggestions on the IBS and CBS regulations

On May 28, 2026, the Federal Revenue Service and the IBS Steering Committee extended the deadline for submission of suggestions on the IBS and CBS regulations to June 15, 2026, at 6:00 p.m
Taxpayers may submit proposals to improve the regulatory texts through their representative industry associations, using the Receita Atende channel.

The contributions received will be analyzed by the technical teams of the competent authorities and may be incorporated into new versions of the regulations

Ministry of Finance and Office of the Comptroller General create group to study remuneration of federal tax collection and split payment

On May 12, 2026, an interministerial ordinance was published creating a temporary advisory and study working group, with the purpose of assessing and proposing pricing and remuneration models for the federal tax collection network, as well as the operationalization of the split payment mechanism.

The group will be responsible for separately assessing the remuneration models for federal tax collection and split payment, discussing technical and regulatory mechanisms for their implementation, and preparing a final report with conclusions and proposals to be submitted to the Ministry of Finance.

The group includes representatives of the Ministry of Finance and the Federal Revenue Service, in addition to the consultative participation of the Office of the Comptroller General. Representative institutions from the financial sector may also participate collaboratively, and representatives of the IBS Steering Committee may be invited to discussions related to split payment.

Federal Revenue Service publishes new version of the Tax Reform Glossary

On May 8, 2026, the Federal Revenue Service published the third version of the consumption tax reform glossary. The material provides an overview of the new rules and details the operation of IBS and CBS, with the purpose of standardizing concepts and facilitating understanding of the new tax system.

According to the glossary, the reform seeks to simplify taxation by unifying the legislation currently applicable to ICMS, within the jurisdiction of the states, and ISS, within the jurisdiction of the municipalities, into a single body of legislation for IBS, thereby reducing normative complexity.

Another point highlighted is transparency, with the requirement to show the amount of the tax on the invoice, allowing taxpayers greater clarity regarding the amount paid.

See below the additions and amendments included in the Tax Reform Glossary:

API Key: a unique code used to authenticate and authorize a user, developer, or application.

Electronic Passenger Ticket (BP-e): an electronic tax document for intermunicipal and interstate road passenger transportation services. Its purpose is to implement a national model of electronic tax document to replace the current paper-based issuance model. Its legal validity is ensured by the digital signature of the issuer, simplifying taxpayers’ ancillary obligations and allowing the tax authorities to monitor commercial transactions in real time.

Body/Payload: the body of the request or response, containing the actual data transmitted, such as JSON or XML. Term related to API.

Electronic Bill of Lading (CT-e): an electronic tax document for cargo transportation transactions. Its function is to document, for tax purposes, cargo transportation services rendered through any mode of transport (road, air, rail, waterway, and pipeline). Its legal validity is ensured by the digital signature of the issuer, guaranteeing authorship and integrity, and by receipt and authorization for use by the tax authorities.

Endpoint: a specific address (URL) where the API receives requests and provides access to a resource.

Header: additional information sent in the request/response, such as content type or tokens. Term related to API.

JSON (Java Script Object Notation): a text format used on the web to exchange information between systems, applications, and services. A JSON file is used to store and transmit structured data in a simple, organized, and readable manner for both humans and machines.

Electronic Manifest of Tax Documents (MDF-e): a project aimed at implementing a national model of electronic tax document to replace the current paper-based issuance model. Its legal validity is ensured by the digital signature of the issuer, simplifying taxpayers’ ancillary obligations and allowing the tax authorities to monitor commercial transactions in real time. The MDF-e must be issued by transportation service providers for services involving more than one bill of lading, or by other companies in transactions whose transportation is carried out by their own vehicles, leased vehicles, or through hiring of an autonomous cargo carrier, with more than one invoice.

Electronic Electric Energy Invoice (NF3e): an electronic tax document for electricity supply services, replacing the traditional electricity bill. Its purpose is to implement a national model of electronic tax document to replace issuance of the Electricity Invoice/Bill. Its legal validity is ensured by the digital signature of the issuer, simplifying taxpayers’ ancillary obligations and allowing real-time monitoring of issuance by the tax authorities.

Electronic Services Invoice (NFS-e): an electronic tax document used to document service transactions.

Webhook: a specific address (URL) to which the API returns information.

XML: eXtensible Markup Language. It is a structured digital file format used to organize, store, and transport data in a standardized manner. It can be read by both humans and machines.

Failure to complete IBS and CBS fields may block issuance of NF-e as from August 2026

On May 20, 2026, a new version of the technical note addressing the adjustments to the Electronic Invoice and the Electronic Consumer Invoice arising from the tax reform was published.

According to the technical note, as from August 3, 2026, completion of the IBS and CBS fields in tax documents will become mandatory, so that absence of such information may prevent authorization of the NF-e and NFC-e.

The technical note also establishes the implementation schedule, with the testing environment starting on July 1, 2026 and production going live on August 3, 2026.

Federal Revenue Service launches new version of the National Consumption Tax Reform Dashboard focused on automation and integration

On May 19, 2026, the Federal Revenue Service presented new functionalities of the Digital Platform for the Consumption Tax Reform, with improvements focused on automation, transparency, and systems integration.

The improvements include application programming interfaces, assisted CBS calculation, and new tools for management of credits and payments. According to the Federal Revenue Service, the evolution of the platform will enable automation of CBS debt queries, integration of business systems with the tax reform platform, and access to updated tax data.

The assisted calculation feature also began to automatically process different tax documents, including supplementary invoices, debit notes, and transport loss events, thereby increasing calculation accuracy.

In addition, functionalities were included for simulation of credit refunds and expression of intent to request refunds, allowing taxpayers to manage the use of credit balances during the tax calculation period.

The Federal Revenue Service also informed that future versions should include new functionalities related to collection documents, payment and CBS credit queries, improvements to the tax reform calculator, and new services linked to the NFS-e.

Ministry of Ports and Airports proposes tax reform regulation to expand regional aviation

On May 13, 2026, the Ministry of Ports and Airports presented a proposal for regulation of the tax reform with the purpose of expanding application of the benefits provided for the aviation sector, especially with respect to regional aviation.

The proposal provides that the 40% reduction of IBS and CBS rates should be applied considering the entire air network operated by the company, rather than only isolated routes.

The model is based on the premise that regional aviation operates in an integrated manner, in which lower-demand routes depend financially on more profitable flights. In this context, regional airlines would be those allocating 50% of their seat capacity to regional routes, allowing broader use of the tax benefit to support the expansion and maintenance of flights to the interior of the country.

The proposal is currently under discussion with the Ministry of Finance and the Attorney General of the National Treasury.

Reforma Tributária enfrenta pressão de projetos no Congresso

At the end of May, news reports indicated that the National Congress had already accumulated around 50 bills aimed at amending aspects of the consumption tax reform. Of those bills, approximately 70% concern changes to the Selective Tax, while the others seek to broaden exceptions relating to IBS and CBS.

The proposals cover issues such as expansion of favorable regimes, rate reductions for food, agribusiness, construction, technology, and strategic sectors, as well as changes to credit rules, tax incentives, and customs regimes linked to IBS and CBS.

In the case of the Selective Tax, the bills seek to adjust the incidence criteria applicable to fuels, cigarettes, plastics, sugar-sweetened beverages, and environmentally impactful products, as well as rules relating to the Manaus Free Trade Zone and the Free Trade Areas.

The bill that will define the rates of the Selective Tax has not yet been submitted.

CARF updates internal rules to incorporate CBS and Selective Tax and changes procedural rules

On May 22, 2026, an ordinance of the Ministry of Finance was published amending the internal rules of the Administrative Council of Tax Appeals in order to adapt them to the changes introduced by the tax reform and to promote procedural and administrative adjustments.

The amendment includes CBS and the Selective Tax among the matters under the jurisdiction of the administrative court. It also begins to provide for the use of decisions and precedents issued by the National Chamber for Integration of Administrative Litigation of IBS and CBS as references in judgments, in addition to limiting the filing of special appeals in matters relating to CBS that are common to IBS.

The new rules entered into force on the date of publication of the ordinance.

Rio Grande do Sul regulates assisted IBS calculation pilot project

On May 22, 2026, the State Revenue Service of Rio Grande do Sul established a pilot project for the IBS assisted calculation system, aimed at validating the technological solutions applicable to implementation of the new tax.

The project will be monitored by the operational technical committee of the IBS Steering Committee and will allow participation by companies issuing electronic tax documents.

The purpose of the pilot is to test functionalities, systems integration, and anticipation of adjustments required for the future IBS calculation system.

The normative act produces effects as from May 22, 2026.

Tocantins updates tax litigation framework and incorporates Tax Reform-related rules

On May 5, 2026, the State of Tocantins published a Provisional Measure amending the legislation governing state administrative tax litigation.

The measure aligns local legislation with the new tax reform model by including IBS within the scope of administrative litigation and providing for integrated action with the Steering Committee of the tax.

In addition, deadlines for objections, appeals, and responses will henceforth be counted in business days.

The act also provides for new procedural instruments, such as mandatory review and review appeal in cases of divergent decisions.

The measure also clarifies that certain taxpayer conduct may terminate or affect the administrative dispute. Payment, installment payment, or judicialization of the matter may represent withdrawal from the administrative dispute, whereas failure to present a defense may lead to recognition of the tax obligation.

Municipality of São Paulo discloses new obligations for issuance of NFS-e in the context of the Tax Reform

On May 19, 2026, the Municipal Finance Secretariat of São Paulo disclosed changes relating to issuance of the Electronic Services Invoice in the municipality. The measures involve mandatory use of the National NFS-e Issuer by Simples Nacional taxpayers and inclusion of new IBS and CBS fields in tax documents.

As from September 1, 2026, companies opting for Simples Nacional must issue the NFS-e exclusively through the National Issuer. The requirement also extends to companies whose request to elect the regime is still under review, those involved in administrative disputes that may result in retroactive inclusion in Simples Nacional, and those subject to temporary impediment provided for in the legislation.

For self-employed professionals and individuals falling under specific exemption situations, use of the National Issuer will be required as from August 1, 2026.

The same date marks the beginning of the requirement to complete the new IBS and CBS fields in the NFS-e, including in cases of importation of services. Failure to comply with the new rule may subject taxpayers to the applicable penalties.

The Municipal Finance Secretariat clarified that the previous layout will remain available only for retroactive issuances and that issuance of the Invoice of the Service Recipient/Intermediary will continue to be carried out under the old layout. After the migration deadlines, the municipal NFS-e system will remain available only for consultation and retroactive issuance of tax documents.

This publication is intended for informational purposes only and does not constitute legal advice. Our ​Indirect Tax​ team remains available to provide specific legal guidance tailored to your business needs.