Introductory Guide to Assisted Tax Assessment: The Essential Components

What is Assisted Tax Assessment?

Assisted Tax Assessment is a system developed by the Brazilian Federal Revenue Service (Receita Federal) to calculate the results of a taxpayer’s operations under the new Goods and Services Tax (IBS) and Contribution on Goods and Services (CBS) model.

It represents the practical implementation of the constitutional principle of simplicity introduced by the Tax Reform, which aims to reduce the burden of ancillary obligations.

In practice, the tax administration performs the calculations and provides a pre-filled assessment, leaving the company responsible only for validating, adjusting, or contesting the presented data.

As a result, companies shift their role, they are no longer the "calculators" of the tax, but rather act as validators and auditors of the assessment.

The Foundation of the System: Electronic Tax Documents (DF-e)

The central role of DF-e

The entire Assisted Tax Assessment system is based on Electronic Tax Documents (DF-e).

Every purchase, sale, or service provision recorded through a DF-e automatically feeds the taxpayer’s assessment, becoming the only required ancillary obligation for this process.

Examples of Electronic Tax Documents

• Electronic Invoice (NF-e)

  
  

• Consumer Electronic Invoice (NFC-e)

  
  

• Electronic Service Invoice (NFS-e)

  
  

• Electronic Transport Knowledge (CT-e)

  
  

• Electronic Electricity Invoice (NF3-e)

  
  

• Electronic Ticket (BP-e)

  
  

The DF-e as a confession of debt

Under the Assisted Tax Assessment model, the mere issuance of a DF-e constitutes a confession of debt for the taxes (IBS and CBS) levied on that operation.

This eliminates the need for complementary filings such as the DCTF, which traditionally formalized the taxpayer’s liabilities.

These documents are the primary data source for the four components that determine the monthly tax calculation.

The Four Fundamental Components of Assisted Tax Assessment

1. Debits: the taxable event

Debits represent the amount of IBS and CBS generated by the company’s sales or service operations — that is, the tax owed as a result of its revenue.

2. Credits: the principle of non-cumulative taxation

Credits are amounts the company is entitled to deduct from its debits, ensuring compliance with the non-cumulative taxation principle.The main sources of credits include:

• Purchases of goods and services used in the business operation;

  
  

• Presumed credits granted by law;

  
  

• Recoverable balances from previous periods.

  
  

3. Adjustments: corrections to the assessment

The company may apply positive or negative adjustments to the balance calculated by the tax authority, using specific tax documents such as:

• Debit notes, to increase the amount due;

• Credit notes, to reduce it.

  
  

4. Deductions: extinguishing the tax liability

Deductions correspond to amounts already paid or offset, preventing duplicate taxation. They may occur through:

• Split Payment;

  
  

• Withholding by the purchaser;

  
  

• Payment by a tax substitute or responsible party;

  
  

• Direct payment via collection document;

  
  

• Compensation with existing tax credits.

  
  

These four elements work together to determine the taxpayer’s monthly assessment result.

The Logic of Calculation: Debits, Credits, and the Final Balance

The Assisted Tax Assessment operates like a tax current account.

Just as in a bank statement, the system records debits (outflows) and credits (inflows), applies adjustments and deductions, and then presents the final balance.

Assessment Result	Description
Positive Balance	Represents the amount of IBS and CBS payable.
Negative Balance	Represents a recoverable credit, which may be refunded or offset.

The Role of the Taxpayer: Validate, Adjust, or Contest

Receiving the assessment

Each month, the tax administration will provide the taxpayer with a demonstrative report containing the pre-filled calculation, detailing entries, exits, and the final balance.

Three possible actions for the taxpayer

1. Validate: Confirm that the assessment provided by the tax authority is correct, thereby formalizing the tax liability.

   
   

2. Adjust: Make legally permitted corrections, such as issuing debit or credit notes.

   
   

3. Contest: Formally dispute discrepancies by submitting justification to the Federal Revenue Service.

   
   

Consequence of inaction

If the taxpayer does not respond within the legal timeframe, the system will assume that the pre-filled assessment is correct, and the tax credit will be automatically constituted based on that value.

Conclusion: A New Fiscal Paradigm

The Assisted Tax Assessment introduces a structural shift in the relationship between taxpayers and the tax administration.

By transferring the calculation responsibility to the tax authority, this model strengthens transparency, simplification, and efficiency in the national tax system.

Source: Brazilian Federal Revenue Service

How Brinta Connects to This New Scenario

Brinta supports companies across Latin America in adapting to the new Assisted Tax Assessment model — automating calculations, centralizing electronic tax documents, and ensuring compliance throughout their operations.

 Talk to the Brinta team and learn how to automate the validation of your tax assessment under the new IBS and CBS model.