Cost Sharing and the Incidence of IBS and CBS: Between Reimbursement and a Taxable Transaction

The Tax Reform on consumption, enacted by Complementary Law No. 214/2025, introduced a substantial change in the logic of tax incidence by establishing the Tax on Goods and Services (IBS) and the Contribution on Goods and Services (CBS) over a broader taxable base structured around criteria of economic substance.

As a general rule, the new regime provides for taxation on onerous transactions involving goods or services. However, the law itself expressly establishes situations in which non-onerous transactions may also be subject to taxation, through legal equivalence or statutory fiction, in order to preserve system neutrality and prevent distortions within the economic chain.

It is within this expanded regulatory framework that one of the most sensitive issues for corporate groups arises: the tax treatment of cost-sharing agreements, particularly when structured under a reimbursement model.

The Concept of Onerous and Non-Onerous Transactions Under Complementary Law No. 214/2025

For a proper analysis of the matter, it is necessary to examine the provisions that define the taxable events.

Pursuant to Article 4 of Complementary Law No. 214/2025, IBS and CBS apply to onerous transactions involving goods or services. Paragraph 3 of that provision establishes that, for purposes of characterizing the transaction, the nature, type, or legal form of the agreement, as well as the existence of profit, are irrelevant.

From this wording, it follows that the onerous nature of a transaction does not depend on the existence of a margin or profit, but rather on the presence of a relationship involving reciprocal obligations capable of revealing an economic consideration, even within a corporate group.

In turn, Article 5 of Complementary Law No. 214/2025 lists specific situations in which taxation applies to non-onerous transactions, demonstrating that the legislator adopted a technique of expanding taxable events through express legal equivalence. This constitutes a closed list, which must be interpreted restrictively.

Therefore, not every transaction without a price will be subject to taxation, but only those expressly provided for by law. The absence of consideration, in itself, does not automatically exclude taxation; however, it also does not authorize its extension by analogy beyond the legally established situations.

At this point, the central question arises: do cost-sharing agreements constitute an onerous transaction, a legally equated non-onerous transaction, or merely a reimbursement outside the scope of taxation?

Cost Sharing from an Economic Perspective

Within corporate groups, cost-sharing agreements are instruments used to allocate expenses related to common corporate activities, such as administrative support, information technology, human resources, strategic management, or compliance.

The usual practice consists of centralizing certain costs in one group company, which subsequently allocates them among the beneficiary entities. To formalize this transfer, commercial and accounting debit notes are generally issued to document the reimbursement, without any markup.

Under the previous tax regime, when the so-called “pure reimbursement” was characterized, the prevailing understanding was that there was no independent service provision or taxable revenue, precisely because the amounts received did not constitute new income to the taxpayer’s assets, but merely a reimbursement of expenses incurred on behalf of third parties. In the absence of an actual increase in the company’s assets, there was no taxable event.

The Tax Reform, however, requires this practice to be reassessed in light of the expanded concept of taxable economic substance.

Pure Reimbursement and Allocation of Own Costs: A Necessary Distinction

For a more accurate technical analysis of the scenarios, it is essential to distinguish between the two charging models.

In the case of pure reimbursement, the centralizing company acts merely as an intermediary, making payments on behalf of the other group companies without performing any activity of its own related to the expense. In this situation, the transfer of funds represents a simple restoration of assets, with no supply of goods or provision of services.

Complementary Law No. 214/2025 itself, in Article 12, §2, IV, provides that reimbursements or refunds received for amounts paid on behalf of or in the name of third parties do not form part of the taxable base of IBS and CBS, provided that the tax documentation is issued in the name of the third party.

This provision reinforces that, where an actual payment on behalf of a third party is characterized, there is no taxable base. Compliance with the requirement that the tax document be issued in the name of the third party is also essential for this interpretation.

A different situation arises when the centralizing company performs its own corporate activities, maintains a dedicated organizational structure—with internal departments, personnel, assets, and processes—and assumes costs inherent to its own organization, subsequently allocating these amounts among the other group companies.

In this case, even in the absence of a profit margin, the operational dynamics may evidence the effective provision of intra-group services. In light of Article 4, §3, of Complementary Law No. 214/2025, the absence of a positive result is legally irrelevant for the characterization of onerousness; it is sufficient that there be a relationship with identifiable economic content. In this context, the allocation may be interpreted as actual consideration for internal services made available to the beneficiary companies, revealing an obligational relationship with its own economic substance and, therefore, subject to IBS and CBS.

The distinction between restoration of assets and internal service provision thus plays a central role in assessing tax risk.

Transition Scenario: Supporting Documentation for Cost Sharing

For fiscal year 2026, the transition period of the new system, it is possible to argue that, provided the characterization of pure reimbursement is maintained, transactions may continue to be documented through commercial instruments such as debit notes, internal invoices, or allocation statements.

However, as of 2027, with the full enforceability of IBS and CBS, the mere absence of profit will no longer be sufficient to prevent taxation. It will be essential to demonstrate, through robust contractual, accounting, and documentary support, that the transaction constitutes an actual payment made on behalf of and in the name of third parties, rather than the provision of internal services.

To date, there is no specific regulation addressing the documentation applicable to cost-sharing agreements, which reinforces the need for proper prior legal qualification of the transaction.

It is also worth noting that the documents referred to as Debit and Credit Notes, recently established by Technical Notes guiding the tax reform, are intended solely for the purpose of adjusting the calculation of IBS and CBS and should not be confused with the commercial instruments currently used to formalize reimbursements.

Final Considerations

The Tax Reform shifts the debate from a formal to a substantive approach, prioritizing the analysis of the economic substance of the transaction. Moreover, it expands the scope of taxation by expressly providing for taxable events even in certain non-onerous situations.

In this context, cost-sharing agreements can no longer be assessed solely from an accounting perspective; they now require a structured analysis capable of evidencing the true nature of the transfer of funds.

The proper delineation between pure reimbursement, an onerous transaction, and any potential legally equated non-onerous transaction will be decisive in mitigating tax risks under the IBS and CBS regime. More than a documentary issue, this matter involves contractual structuring, corporate governance, and the economic consistency of intra-group transactions.

Anticipating this analysis, even during the transition period, represents a relevant prudential measure to ensure legal certainty and predictability within the new consumption tax system.