Belgium has granted multinational and large domestic groups additional time to comply with Pillar Two minimum tax requirements, pushing all filing deadlines for QDMTT and IIR declarations.
Belgium’s Federal Public Service (SPF) Finance has announced, on 3 April 2026, the extension of the filing deadlines for Pillar Two minimum tax declarations. The extensions apply to both the Qualified Domestic Minimum Top-up Tax (QDMTT) and supplementary tax under the Qualified Income Inclusion Rule (IIR).
QDMTT declaration extension
Under the original law from 19 December 2023, companies were required to submit QDMTT declarations by the last day of the eleventh month after their fiscal year-end. The deadline initially set for 17 November 2025 has now been pushed back.
For fiscal years beginning on or after 31 December 2023 and ending between 1 January 2024 and 30 September 2025, companies now have until 30 September 2026 to file their national supplementary tax declarations.
IIR supplementary tax filing changes
The IIR filing requirements follow different timelines depending on when the fiscal year begins.
The standard deadlines were set at fifteen months after year-end for fiscal years starting from 1 January 2025, and eighteen months for those beginning by 31 December 2024.
Both categories have received extensions:
- Fiscal years starting on or after 1 January 2025 and ending by 31 May 2025: extended to 30 September 2026
- Fiscal years beginning between 31 December 2023 and 31 December 2024, ending by 28 February 2025: also extended to 30 September 2026.
