Short answer: Brazil’s Additional CSLL is the country’s Qualified Domestic Minimum Top-up Tax (QDMTT). It targets Brazilian constituent entities of multinational groups within the GloBE scope and seeks a 15% effective tax rate in Brazil. The general group threshold is EUR 750 million of consolidated annual revenue in at least two of the four preceding fiscal years. It applies to fiscal years beginning on or after January 1, 2025. [Source: Law 15,079/2024, arts. 1–4 and Receita Federal — AdCSLL.]
For a calendar-year group, any Additional CSLL due for the year ended December 31, 2025 had to be paid by July 31, 2026. Being within scope does not by itself mean that tax is payable. A group must map its Brazilian entities, GloBE income, covered taxes, elections and exclusions before determining the amount, if any. [Source: Receita Federal guidance, July 8, 2026.]
What Brazil’s QDMTT is — and what it is not
The Additional CSLL is a domestic top-up tax calculated under Brazil’s GloBE-aligned rules. Its purpose is to bring the effective tax rate on covered Brazilian operations up to the 15% minimum where the jurisdictional calculation produces a shortfall. The calculation is jurisdictional: it is not a second ordinary CSLL rate simply applied to each company’s Brazilian taxable profit. [Source: Law 15,079/2024, arts. 2 and 9 onward.]
This distinction matters. Ordinary IRPJ and CSLL are part of Brazil’s corporate income-tax system and can enter the GloBE covered-tax calculation, subject to the adjustments required by the GloBE rules. Additional CSLL is a separate top-up mechanism. Start with our ordinary IRPJ and CSLL guide if the question is the normal Brazilian corporate tax charge, and use this guide when the group is testing Pillar Two exposure. [Source: Law 15,079/2024.]
A practical scope test
Use this as a screening sequence, not as a substitute for the statutory calculation:
- Identify the ultimate parent and consolidated group. The group-level test cannot be performed entity by entity.
- Test the revenue threshold. Check whether consolidated annual revenue reached at least EUR 750 million in at least two of the four immediately preceding fiscal years. [Source: Law 15,079/2024, art. 4.]
- Map every Brazilian constituent entity. Include ownership, fiscal year-end and the relationship between local books and the consolidation package.
- Identify statutory exclusions and special events. Mergers, demergers, short fiscal years and excluded entities can change the result. TO_CONFIRM: a group should not treat failure of a simplified threshold check as a final legal conclusion without applying the detailed GloBE rules.
- Run the Brazilian jurisdictional calculation. Determine GloBE income or loss, adjusted covered taxes, the effective tax rate and any top-up amount under the applicable rules. [Source: Receita Federal — AdCSLL calculation overview.]
Ordinary CSLL versus Additional CSLL
| Question | Ordinary CSLL | Additional CSLL / QDMTT |
|---|---|---|
| Main purpose | Brazilian social contribution on company profit | Domestic top-up to the GloBE minimum |
| Scope | Determined under ordinary Brazilian corporate-tax rules | Covered multinational groups under Law 15,079/2024 |
| Core measurement | Entity-level taxable profit rules | Jurisdictional GloBE effective tax rate |
| Key percentage in this guide | Not restated here | 15% minimum effective rate |
| First question for the reader | What is the company’s ordinary taxable base? | Is the multinational group within GloBE scope? |
The table is a navigation aid. It does not mean ordinary CSLL and Additional CSLL are economically unrelated: covered-tax adjustments can connect local corporate taxes to the GloBE calculation. A calculation requires entity and consolidation data, not only a local tax return. [Source: Law 15,079/2024.]
How the calculation works at a high level
The Brazilian rules determine GloBE income or loss and adjusted covered taxes for Brazilian constituent entities. Those amounts feed a jurisdictional effective tax rate. If the rate falls below 15%, the rules determine the top-up percentage and Additional CSLL after the adjustments, exclusions and elections that apply. [Source: Receita Federal — AdCSLL.]
For a CFO, the operational challenge is usually the data bridge. The group should be able to reconcile the consolidation package, local ledgers, current and deferred tax data, ownership changes and entity allocations. A spreadsheet based only on the ordinary CSLL tax base is not a complete QDMTT model.
Brazil’s QDMTT and QDMTT Safe Harbour were recorded as qualified in August 2025, according to Receita Federal’s AdCSLL page and the OECD central record. Qualification status should be rechecked before a filing or cross-border Pillar Two position because the OECD record can be updated. [Sources: Receita Federal — AdCSLL and OECD central record.]
Payment and DCTFWeb workflow in 2026
Any Additional CSLL due must be paid by the last business day of the seventh month after the fiscal year ends. For an entity with a December 31, 2025 year-end, any amount due had to be paid by July 31, 2026. [Source: Law 15,079/2024, art. 33 and Receita Federal guidance, July 8, 2026.]
Receita’s July 2026 instructions use the sixth month after year-end as the DCTFWeb assessment period, with the declaration due on the last business day of the following month. The group can pay entity by entity using revenue code 1809-01, or centralize payment in one Brazilian entity using 1809-02. [Source: Receita Federal guidance, July 8, 2026.]
Before generating the payment document, document three decisions: the fiscal year-end used, whether payment is separate or centralized, and how the amount is allocated back to the Brazilian constituent entities. Live DCTFWeb instructions and the revenue code should be checked again at filing time.
What about the separate information return?
Payment and DCTFWeb are already operational, but Receita stated in July 2026 that a separate Additional CSLL information return was still being developed. For the first fiscal year, the obligation will not be required before the eighteenth month after year-end. For a December 31, 2025 year-end, Receita said it would not be required before June 30, 2027. Receita did not establish a “last business day of the eighteenth month” rule. [Source: Receita Federal guidance, July 8, 2026.]
TO_CONFIRM before publication or filing: the final form, schema and definitive deadline of that separate information return once Receita issues the regulation. Do not confuse this future obligation with the current DCTFWeb payment workflow.
CFO and tax director checklist
- Confirm the ultimate parent, group fiscal year and four-year revenue history.
- Inventory all Brazilian constituent entities and ownership changes.
- Assign owners for consolidation, local accounting, tax and deferred-tax data.
- Build a reconciliation from local ledgers to the GloBE data package.
- Model separate versus centralized payment and retain the allocation support.
- Validate the DCTFWeb assessment period, deadline and revenue code at filing time.
- Track the separate information-return regulation as an open compliance item.
- Connect QDMTT governance to Brazilian tax compliance, transfer pricing and the broader corporate tax guide.
FAQ
Does Brazil’s QDMTT apply to our multinational group?
The initial test is whether the group had at least EUR 750 million of consolidated annual revenue in at least two of the four preceding fiscal years. The final analysis also requires the detailed GloBE scope, exclusions and Brazilian constituent-entity rules. [Source: Law 15,079/2024, art. 4.]
How is Additional CSLL different from ordinary CSLL?
Ordinary CSLL follows Brazilian corporate-income rules. Additional CSLL is a jurisdictional GloBE top-up mechanism intended to reach a 15% effective rate for covered Brazilian operations. [Source: Law 15,079/2024, art. 2.]
When was any Additional CSLL due for 2025 payable?
For a calendar-year group with a December 31, 2025 year-end, any Additional CSLL due had to be paid by July 31, 2026. Other year-ends follow the last-business-day rule for the seventh month after year-end. [Source: Receita Federal guidance, July 8, 2026.]
How is Additional CSLL reported in DCTFWeb?
Receita instructs taxpayers to use the sixth month after year-end as the assessment period and file by the last business day of the following month. Codes 1809-01 and 1809-02 distinguish separate and centralized payment. [Source: Receita Federal guidance, July 8, 2026.]
Is a separate information return required?
Receita says a separate return is being developed. TO_CONFIRM: its final form and deadline when regulation is issued. For a December 31, 2025 year-end, Receita said the first deadline would not be before June 30, 2027. [Source: Receita Federal guidance, July 8, 2026.]
Official sources reviewed
Official sources reviewed for this guide: Law 15,079/2024, Receita Federal’s AdCSLL topic page, Receita’s July 8, 2026 operational guidance and the OECD central record of qualified legislation. Accessed August 10, 2026.
This guide is general information, not a calculation or legal opinion. Reconfirm time-sensitive filing instructions against current Receita Federal materials.