Belgium’s tax authority has announced extensions to several corporate tax, multinational enterprise and Pillar Two filing obligations, giving in-scope taxpayers additional time to meet their reporting requirements.
Belgium’s Federal Public Service Finance announced in a series of releases that it is extending the corporate tax filing deadline and tax declaration filing deadlines for multinational enterprises.
Corporate tax filing deadline to 15 October
Belgium’s tax authority (FPS Finance) has announced on 25 September 2026 an exceptional extension of tax filing deadlines following consultations with industry professionals. The deadline for corporate income tax returns filed by companies, legal entities, and non-resident companies has been extended from 30 September 30 to 15 October 2026.
Select PIT returns to 31 October
The deadline for personal income tax returns filed through Tax-on-web has also been extended from 16 October to 31 October 2026.
Extension of tax declaration filing deadlines for multinational enterprises
The Belgian tax authorities have also extended filing deadlines for two critical tax declarations under the law of 19 December 2023 in an announcement on 28 September 2026. This legislation introduced minimum tax requirements for multinational enterprise groups and large domestic groups. The extension pushes all in-scope filing deadlines to 31 October 2026.
Supplementary national tax declarations extended (QDMTT)
The original deadline for filing supplementary national tax declarations, formally known as Qualified Domestic Minimum Top-up Tax (QDMTT) returns, was set for 3 April 2026. This deadline has been postponed to 31 October 2026 inclusive for all relevant tax years.
The extension applies to declarations covering fiscal years that began on or after 31 December 2023 and ended no later than 31 October 2025. Companies subject to these reporting obligations now have until the end of October 2026 to file their QDMTT returns.
RIR supplementary tax declarations
The Qualified Income Inclusion Rule (RIR) requires separate supplementary tax declarations with their own filing timelines. Belgium has extended these deadlines uniformly to 31 October 2026 for multiple filing scenarios.
For fiscal years beginning on or after 1 January 2025 and ending no later than 30 June 2025, the normal deadline was the fifteenth month after the fiscal year closed. For tax years starting from 31 December 2023 through 31 December 2024, the deadline was eighteen months after year-end. Both groups now file by 31 October 2026.
General representative notification
Entities filing supplementary national tax returns must appoint and notify a general representative for each fiscal year. This notification must be submitted before the QDMTT return is filed, with no separate extended deadline beyond the October deadline.
Pillar Two notification deadline extended
In another release on 28 September 2026, Belgium has postponed the deadline for submitting GIR reporting entity notifications to 31 October 2026 for specified fiscal years.
The extension covers notifications relating to GIR information reports for fiscal years beginning on 1 January 2025 and ending by 30 June 2025, as well as certain fiscal years beginning between 31 December 2023 and 31 December 2024 and ending by 31 March 2025.
