This article argues that the recent amendments to the Internal Rules of the Administrative Council of Tax Appeals (CARF), introduced by Ordinance MF 1.398/2026, are essential to ensuring legal certainty and predictability during the transition to the new consumption taxation model. The standardization of deadlines and the requirement for highly qualified counselors emerge as mechanisms to mitigate litigation in a context of profound legislative changes.

Introduction
The Brazilian Tax Reform is not limited to changing tax rates or unifying taxes; it requires a deep restructuring of administrative adjudication bodies. CARF, as the highest authority for resolving federal tax disputes, assumes a central role in interpreting the new CBS and IBS rules. The central thesis defended here is that procedural simplification is the only way to prevent the collapse of administrative litigation in the face of the new systemic complexity.

Development and Grounds
One of the most significant advances is the adoption of procedural deadlines counted in business days, aligning CARF’s Internal Rules (RICARF) with the 2015 Civil Procedure Code. This measure eliminates the coexistence of different counting methods, which previously generated legal uncertainty and procedural errors for both taxpayers and government attorneys.

Beyond formality, Ordinance MF 1.398/2026 focuses on substance. The new requirement that counselors demonstrate broad knowledge of federal taxes, in addition to registration with professional bodies, aims to strengthen the technical qualification of judgments. During a period in which the tax system will be hybrid (coexistence of the old and new models), the expertise of adjudicators becomes the last barrier against arbitrary or technically inconsistent decisions.

The centralization of federal tax judgments within CARF, reaffirmed by the Federal Government, consolidates the body as the technical authority responsible for resolving disputes involving CBS. The council’s president, Carlos Higino Ribeiro de Alencar, emphasizes that this standardization brings clarity and simplicity, which are essential elements for a stable business environment.

Conclusion
Therefore, the modernization of CARF is not merely bureaucratic, but strategic. By prioritizing legal certainty and rationalization, the body prepares the ground for the Tax Reform to achieve its objective of making the Brazilian system more predictable and less litigious.