Summary
- The Belgian tax administration has extended the deadline for specified qualifying domestic minimum top-up tax, or QDMTT, and income inclusion rule, or IIR, returns to 31 October 2026. The extension applies to defined reporting periods for which the statutory filing deadlines would otherwise fall before that date. [financien.belgium.be]
- The relief is relevant to multinational enterprise groups and large domestic groups falling within Belgium’s Pillar Two rules. Groups with multiple Belgian entities subject to the QDMTT must also appoint a general representative, with the corresponding notification due no later than the filing of the QDMTT return. [financien.belgium.be], [financien.belgium.be]
- Affected groups should use the additional time to validate calculations, confirm the filing entity and general representative, obtain the necessary Belgian electronic access rights, and test the required XML files. The returns and related notifications are submitted electronically through MyMinfin, using the applicable Pillar Two role or mandate. [financien.belgium.be], [financien.belgium.be], [financien.belgium.be]
Article
The Belgian tax administration announced on 28 September 2026 that the filing deadlines for certain qualifying domestic minimum top-up tax, or QDMTT, and income inclusion rule, or IIR, returns have been extended to 31 October 2026.
For QDMTT purposes, the extended deadline applies to returns for reporting years beginning on or after 31 December 2023 and ending between 1 January 2024 and 31 October 2025. The administration’s announcement replaces the previously permitted filing date of 3 April 2026 for the affected returns. Belgium’s statutory rule generally requires the QDMTT return to be filed by the final day of the eleventh month following the end of the reporting year. [financien.belgium.be], [financien.belgium.be]
For IIR returns, Belgian legislation ordinarily provides a deadline at the end of the fifteenth month following the close of a reporting year beginning on or after 1 January 2025. An eighteen-month period applies to a reporting year beginning no later than 31 December 2024. The new administrative relief extends the deadline to 31 October 2026 for specified early reporting periods, including years beginning on or after 1 January 2025 and ending no later than 30 June 2025, as well as years beginning between 31 December 2023 and 31 December 2024 and ending no later than 31 March 2025. [financien.belgium.be]
In practice, the announcement means that affected QDMTT and IIR returns with an otherwise applicable filing deadline before 31 October 2026 may benefit from a common filing date. Groups should nevertheless confirm that each reporting period comes within the precise conditions of the extension rather than applying the date automatically to all Belgian Pillar Two obligations.
Where several Belgian constituent entities within a group are liable for the QDMTT, the group must appoint a general representative to file the common return. The related notification must be submitted no later than the filing of the QDMTT return. Operationally, the QDMTT and IIR returns, together with the representative notification, are handled through MyMinfin. XML schemas, filing tools, return models and explanatory documents are available through the Belgian tax administration’s Pillar Two portal. [financien.belgium.be], [financien.belgium.be], [financien.belgium.be]
Groups should use the extension to reconcile Pillar Two calculations with statutory accounts, validate entity and tax identification data, complete internal approvals, and verify that the intended filer has the required Pillar Two role or mandate. The extension changes the filing date but does not remove the underlying return, payment, documentation or governance obligations.
Source Links
- Belgian Federal Public Service Finance: QDMTT and IIR deadline announcement
- Belgian Federal Public Service Finance: Pillar Two return requirements
- Belgian Federal Public Service Finance: Pillar Two forms and electronic filing tools
- Belgian Federal Public Service Finance: Pillar Two mandate and access requirements
