Belgian Pillar Two filing framework now operational

Belgian Pillar Two filing framework now operational as filing forms and administrative guidance become available.

Executive summary

Belgium has entered the final phase of implementing its Pillar Two compliance framework.

Over the course of the past days and weeks, the Belgian tax authorities (BTA) have finalized and published various Pillar Two filing forms, the corresponding XSD schemas and the supporting administrative guidance required for taxpayers to comply with their Belgian Pillar Two obligations. In addition, the relevant filing platforms have been progressively opened, enabling taxpayers to prepare and submit the required filings.

These developments provide long-awaited certainty regarding the practical implementation of Belgium's Pillar Two compliance framework and come ahead of the first (extended) major compliance deadline of 30 September 2026, which applies to the GIR Notification, the Qualified Domestic Minimum Top-up Tax (QDMTT) return, and the Income Inclusion Rule (IIR) return obligations. For additional information, please refer to our previous Tax Alert. Furthermore, the Belgian Institute for Tax Advisors and Accountants (ITAA) communicated that no penalties will apply for a GIR filed after the end of June initial deadline, provided that the GIR is filed by 30 September 2026, aligning with the QDMTT and IIR filing date. A parliamentary question formally confirming the administrative tolerance is expected. 

In parallel, the BTA also released administrative guidance, including a dedicated Frequently Asked Questions (FAQ) dealing with practical aspects of the QDMTT return and the concept of the General Representative for purposes of the IIR and UTPR regimes.

Taxpayers should not limit their Pillar Two compliance planning to the 30 September 2026 deadline. As the Belgian QDMTT return is, in principle, due within 11 months after the group’s fiscal year-end, groups with a fiscal year ending on 31 December 2025 will need to submit a second wave of Belgian QDMTT returns by 30 November 2026 (i.e. only two months after the first (extended) QDMTT filing deadline).
 

What has been completed?

The Belgian authorities recently finalized several important building blocks of the Belgian Pillar Two compliance framework.
 

Publication of the QDMTT return

The Belgian QDMTT return template has been formally published together with its associated XSD schema. In addition, to the general QDMTT return guidance, the BTA also issued a specific FAQ list, addressing several practical implementation questions specifically related to the QDMTT.

The filing portal for submitting QDMTT returns is now also operational through the digital MyMinfin platform.

The BTA previously granted a filing extension until 30 September 2026 for QDMTT returns with an earlier statutory filing deadline. However, as the QDMTT return is, in principle, to be filed within 11 months after the group’s fiscal year, a second wave of QDMTT filings is expected to be filed by the end of November 2026. For additional information, please refer to our previous Tax Alert.
 

Publication of the IIR return

The Belgian IIR return has likewise been formally published, together with the corresponding XSD schema and tax return guidance.

Taxpayers subject to the Belgian IIR can therefore now prepare and submit their first filings through the MyMinfin portal, which also accepts IIR return filings.

Similar to its QDMTT return filing extension, the BTA granted a general extension until 30 September 2026 for the first IIR return filings. However, as a general rule, the IIR return is to be filed within 15 months after the group’s fiscal year.
 

Publication of the GIR Notification form

In early July 2026, the BTA finalized and published the GIR Notification form and its associated XSD specifications. The filing portal for submitting GIR notifications is now also operational through the MyMinfin platform.

The GIR Notification is the mechanism through which the BTA are notified (annually) about the designated filing entity responsible for submitting the GIR. As a reminder, if the group has multiple Belgian entities, the Belgian designated entity is responsible for filing the GIR notification.

Based on an administrative tolerance and communication, the GIR notification must be filed no later than 30 September 2026 for group’s with (1) fiscal years that ended on 31 December 2023 or in 2024, but before 31 December 2024 (i.e., assessment year 2024), and (2) fiscal years that ended on 31 December 2024 or in 2025, but before 31 December 2025 (i.e., assessment year 2025).
 

Administrative guidance and FAQ released

As mentioned above, in addition to the publication of the return-specific guidelines, the BTA have issued specific administrative guidance by means of a dedicated FAQ.

In addition to providing some practical guidance on the application of QDMTT itself, the FAQ also clarifies the role of the so-called General Representative. For additional information as regards this concept of General Representative, please refer to our previous Tax Alert.

The FAQ clarifies when a General Representative must be appointed, which entity can fulfil that role, and how any required designation must be notified through MyMinfin. As a reminder, the General Representative serves as the primary contact with the BTA and is responsible for handling the relevant QDMTT and UTPR compliance obligations on behalf of the Belgian group entities.

In practice, there might not always be a requirement to proactively appoint and submit a formal (separate) General Representative registration as the rules foresee that the entity that will file (for the first time) the QDMTT return, UTPR return or the GIR in Belgium will be deemed to be the General Representative.
 

Looking beyond September 2026

Although significant focus is given to the first milestone deadline of 30 September 2026, taxpayers should start preparing for the next (second) phase of Belgian Pillar Two compliance. In addition to the upcoming filing deadlines, taxpayers may need to submit a UTPR return for the first time, although the BTA have not yet published a final template (a draft version was released on 16 June 2026 for public consultation).
 

Key takeaways

Belgium's Pillar Two compliance framework has now largely moved from a legislative phase to an operational phase.

Taxpayers now have access to the GIR Notification form, QDMTT return, IIR return and the General Representative notification form, along with the corresponding XSD schemas. In addition, the filing portals are now operational.

The tax authorities have provided return-specific guidance as well as a dedicated FAQ list providing further clarification regarding the QDMTT and the General Representative concept.

With the 30 September 2026 deadline rapidly approaching and, given that most corporate taxpayers must also file their annual corporate income tax returns by this date, in-scope multinational groups should use the coming weeks to prepare and avoid a bottleneck at the end of September. In-scope groups that did not yet register for Pillar Two purposes in Belgium should do so as soon as possible as they will otherwise not be able to comply with the upcoming Pillar Two compliance formalities resulting in penalties. 

At the same time, taxpayers should not lose sight of the broader Pillar Two compliance calendar, including the second wave of QDMTT returns due by the end of November 2026 and the accelerated GIR, GIR notification, IIR and (for the first time) UTPR filings that are due thereafter.

In case you need any assistance with the completion of your obligations under the Belgian Pillar Two legislation or more in general with Pillar Two related questions, please do not hesitate to reach out to us or to your dedicated person of contact.