Belgian Pillar Two: key compliance and filing deadlines for in-scope groups
Pillar Two rules introduce a global minimum effective corporate tax rate of 15% to ensure that multinationals and large-scale domestic groups are subject to a minimum level of taxation in every jurisdiction where they operate.
Following the OECD's Global Anti-Base Erosion (“GloBE”) initiative, the European Union adopted Council Directive (EU) 2022/2523. Belgium implemented the Directive through the Law of 19 December 2023, subsequently amended by the Law of 12 May 2024 and the Law of 19 December 2025.
The Belgian Pillar Two rules apply to multinational enterprise groups and large-scale domestic groups with consolidated annual revenues of at least EUR 750 million in at least two of the four fiscal years preceding the fiscal year under review.
This newsflash provides a practical overview of the key Belgian Pillar Two compliance obligations and highlights the main filing and notification deadlines that in-scope groups should now be tracking. It also reflects the latest guidance issued by the Belgian tax authorities (the “BTA”), including the FAQ published on 24 June 2026 and subsequently updated on 14 August 2026.
Key Belgian Pillar Two deadlines at a glance
The table below summarizes the main Belgian Pillar Two compliance deadlines for in-scope groups with a financial year (“FY”) running from 1 January to 31 December:
| Compliance obligation | Deadline / timing | FY ending 31 December 2024 | FY ending 31 December 2025 |
|---|---|---|---|
| GIR | 15 months after year-end (18 months for fiscal years beginning no later than 31 December 2024) | 30 June 2026 | 31 March 2027 |
| GIR filing entity notification | Deadline determined by BTA guidance | 30 September 2026 (based on BTA guidance) | Not yet confirmed by the BTA |
| Belgian IIR return | Same deadline as the GIR | 30 September 2026 (extension by the BTA) | 31 March 2027 |
| Belgian QDMTT return | 11 months after year-end | 30 September 2026 (extension by the BTA) | 30 November 2026 |
| Belgian UTPR return | Same deadline as the GIR | N/A (Belgian UTPR applies only to fiscal years beginning on or after 31 December 2024) | 31 March 2027 |
Key Pillar Two terms:
- GIR: GloBE Information Return
- QDMTT: Qualified Domestic Minimum Top-up Tax
- IIR: Income Inclusion Rule
- UTPR: Undertaxed Profits Rule
Before any Belgian Pillar Two filings can be made, in-scope groups should ensure that they have obtained a Belgian Pillar Two identification number following a notification to the BTA and registration of the group with the Belgian Crossroads Bank for Enterprises. In principle, such notification must be submitted within 30 days following the start of the first fiscal year for which the group falls within the scope of the Belgian Pillar Two rules.
In addition, where several Belgian entities are subject to the QDMTT and/or UTPR (including, for QDMTT purposes, joint ventures and joint venture affiliates), a general representative is required. Absent proactive notification, the entity first filing the relevant tax return or GIR in Belgium is deemed to be the general representative.
The main Belgian Pillar Two compliance obligations are briefly discussed below.
GIR and GIR filing entity notification
The GIR is the cornerstone Pillar Two reporting document. It contains the information required to determine the group's effective tax rate on a jurisdictional basis and to assess the application of the various Pillar Two charging mechanisms across the jurisdictions in which the group operates.
The GIR is generally filed centrally by the ultimate parent entity or another designated filing entity, provided the applicable conditions for central filing and exchange with Belgium are met.
Belgian constituent entities belonging to an in-scope group must also comply with a separate annual notification requirement identifying the entity responsible for filing the GIR on behalf of the group. To simplify compliance, the group may designate a single Belgian constituent entity to submit this notification on behalf of all Belgian constituent entities.
QDMTT return
Belgium applies a QDMTT to ensure that in-scope groups are subject to a minimum effective tax rate of 15% in Belgium.
A QDMTT return must be filed regardless of whether any Belgian top-up tax is ultimately due. This also applies where the group benefits from the transitional Country-by-Country Reporting safe harbour.
IIR return
The IIR operates through a top-down approach. Under this mechanism, a Belgian parent entity may become liable for top-up tax in respect of low-taxed foreign constituent entities within the group.
The amount of top-up tax may be reduced where a QDMTT has already been applied in the relevant jurisdiction.
An IIR return is required only where a Belgian constituent entity is subject to the IIR. Each such entity must file a separate return through its own MyMinfin account, even if no IIR top-up tax is due.
UTPR return
The UTPR acts as a backstop to the IIR. It may result in Belgian constituent entities becoming liable for a share of the top-up tax where low-taxed profits have not been fully brought into charge under an IIR elsewhere in the group.
For Belgium, the UTPR applies only to fiscal years beginning on or after 31 December 2024.
Where one or more Belgian constituent entities are subject to the UTPR, a return must be filed even if no UTPR top-up tax is due. A sole entity files through its own MyMinfin account; where several are subject, a common return is filed by the general representative through its MyMinfin account.
***
CMS Belgium Tax Team is there to assist you
As in-scope groups move into their first full Belgian Pillar Two compliance cycle, attention should now focus on the upcoming filing and notification deadlines.
The CMS Belgium Tax Team would be happy to assist you in navigating the Pillar Two compliance requirements. Please reach out to your regular CMS Belgium contact if needed.
