CBS's assisted assessment pilot opens to all taxpayers in November: what to test before 2027

IRS expands CBS pilot: now it's for everyone

At a press conference held at the Ministry of Finance, in Brasília, this Wednesday, November 11, the Federal Revenue Service announced that it intends to open the pilot environment of the consumption tax reform to all taxpayers, still in November 2026. Until now, access was restricted to the initial group: according to the Federal Accounting Council (CFC), which took part in the press conference, the assisted assessment system was being tested with 500 companies.

The pilot, established by RFB Ordinance No. 549/2025, was created to test the systems and processes of the Contribution on Goods and Services. The news from November 11 is the expansion of this audience: companies outside the initial group will be able to test the system once access is released. For now, however, there is still no set date: the IRS has not yet announced the opening day or the access procedures.

Don't confuse them: pilot, API, and adjustments module follow different schedules

A point of attention for those following the reform's technical timeline: the expansion of the pilot is different from the release of the CBS assessment APIs. The interfaces for querying debits and credits are already available: version 2.0 of the debit and credit query interfaces was released on October 28, with data from the restricted production and beta production environments.

The module where the taxpayer will actually record corrections, however, follows a different pace. The adjustments module for assisted assessment follows a separate schedule. The IRS plans to release the layout in November and make a prototype available in December. In short: an open pilot does not mean a complete system working end-to-end — it is important to plan the tests knowing exactly what each piece delivers.

Why it's worth testing before billing becomes mandatory

For tax and accounting teams, the opportunity is concrete. For accounting firms, the test offers a valuable opportunity: checking how debits and credits appear in the assisted assessment, since the system uses the same database as the API queries, updated as the IRS processes tax documents and events.

The reason not to leave this for the last minute lies in the very legal mechanics of assisted assessment. According to the CBS regulation, once the IRS presents the period's balance, the taxpayer's assessment can only be made through adjustments to it. And the effect of a possible oversight failure is serious: if the company confirms the assessment or makes adjustments, it counts as a debt confession, and if there is no response, the balance is presumed correct and the tax credit is considered established. In other words: once the regime takes effect, reviewing the balance presented by the tax authorities stops being optional and becomes a mandatory routine of the monthly tax closing.

The context: why this matters right now

The rush to test makes sense because the reform's clock hasn't stopped. CBS remains confirmed to take effect on January 1, 2027, when it starts being charged at the full rate and PIS and Cofins cease to exist. That is the moment when assisted assessment shifts from a testing experience to a routine with the legal effect of a debt confession — hence the importance of using the coming weeks of the open pilot to identify discrepancies between what the company issues, what it purchases, and what the IRS is calculating, before this has a real financial consequence.

What to do now

• Map out who on the tax/accounting team will monitor access to the pilot once it is released;
• Review whether the company's systems can already generate the electronic tax documents that feed the assisted assessment in a testing environment;
• Track the three schedules separately: pilot opening (November), adjustments module layout (November), and module prototype (December);
• Use the test to validate the cross-checking between debits, credits, and payments before the model applies to real operations.

This content is for informational purposes only and does not replace guidance from your accounting department, which should assess the specific impact of these deadlines on your company's operations.

If your team wants to understand how Edoo's systems are preparing for the assisted assessment of CBS and IBS, talk to Edoo.