Belgium: Extended filing deadline for domestic minimum top-up tax (DMTT) return
First filing deadline for DMTT returns is now June 30, 2026.
The Belgian tax authorities have announced an extension to the filing deadline for the domestic minimum top-up tax (DMTT) return. The first filing deadline for DMTT returns is now June 30, 2026, aligning it with the GloBE information return (GIR) / top-up tax information return (TTIR).
Under the Belgian law on minimum taxation, the original deadline for filing the DMTT return was the last day of the 11th month following the end of the fiscal year. For fiscal year 2024, this would have been November 30, 2025. The extension applies to fiscal years beginning on or after December 31, 2023, and ending on or after January 1, 2024, but no later than June 30, 2025.
The extension comes as the final DMTT return template has not yet been published, and the Belgian tax administration’s portal is not open for submissions. Additionally, a draft law introducing key compliance aspects into the law on minimum taxation has been submitted to the Belgian Parliament (read TaxNewsFlash).
Read a November 2025 report prepared by the KPMG member firm in Belgium