A committee-approved proposal, not yet an effective rule
The Federal Public Service Finance notice of 12 October 2026 presents a future change to the filing deadline for Belgium’s Qualified Domestic Minimum Top-up Tax return. It states that the draft was approved by the Chamber’s Finance and Budget Committee on 2 October. Parliamentary document DOC 56 1719/003 confirms the wording adopted in committee. That stage is neither final enactment nor publication in the Belgian Official Gazette. [BE_FOD_12_EN] [BE_DOC_003]
The administration expressly says that the new date will become effective only after definitive adoption and publication of the law. Article 24 of the committee text provides for entry into force on the publication date. A compliance team may prepare the future timetable, but should not replace the existing statutory deadline today. The status of the bill and its exact publication date must be verified and retained before the proposal is applied. [BE_FOD_12_EN] [BE_DOC_003]
Fifteen months generally, eighteen months for the transition
Article 19 of the committee text would replace Article 52 of the Law of 19 December 2023. The general filing date would become the last day of the fifteenth month following the fiscal year end. A derogation would move it to the last day of the eighteenth month for fiscal years beginning no later than 31 December 2024. The transitional test therefore uses the opening date of the year, not its closing date or the date compliance work began. [BE_DOC_003] [BE_FOD_12_EN]
The administration illustrates the proposal with a calendar-year group: if the law is published in November 2026, the 2025 QDMTT return would be due by 31 March 2027. This remains a conditional example rather than a self-standing rule. It must be recalculated for each year end, especially a non-calendar or short fiscal year, after checking the text that is ultimately published. [BE_FOD_12_EN] [BE_DOC_003]
The current timetable and the 31 October extension remain separate
In its notice of 28 September 2026, the administration recalled that the Law of 19 December 2023 currently sets the QDMTT filing date on the last day of the eleventh month following the year end. It also announced an administrative extension: returns whose statutory deadline falls before 31 October 2026 may be filed through 31 October 2026. That extension addresses an immediate filing difficulty; it does not yet insert a general fifteen- or eighteen-month deadline into the statute. [BE_FOD_28] [BE_FOD_12_EN]
Teams must therefore track separately the deadline under the statute in force, the administrative extension where it covers the year concerned, and the future deadline resulting from the published law. Merging those layers could create a late filing if the legislative process or publication is delayed. Conversely, the announcement does not suspend data collection, validation or record retention needed for a complete return. [BE_FOD_28] [BE_FOD_12_EN] [BE_DOC_003]
Do not automatically extend the deadline to other Pillar Two filings
The measure analysed here concerns the annual QDMTT return. The 28 September notice discusses the IIR top-up tax return separately and describes different timing rules. The bill also includes provisions on the top-up tax information return and automatic exchange of information under DAC9. Their presence in the same bill does not justify applying the proposed QDMTT deadline automatically to every other filing. [BE_FOD_28] [BE_DOC_003]
Each group should map the obligation, governing provision, fiscal-year opening date and year end. Its internal calendar should distinguish QDMTT, IIR and the information return, with the selected legal basis and deadline for each. A form name, shared software or the identity of a designated filer does not by itself determine the legal classification of the filing. [BE_FOD_28] [BE_DOC_003]
Practical controls to secure now
A dual calendar can manage the uncertainty. The prudent scenario retains the current statutory deadline, adjusted only by an officially applicable administrative extension. A preparatory scenario calculates fifteen months, or eighteen months where the fiscal year began no later than 31 December 2024. An alert linked to the Belgian Official Gazette should be cleared only after checking the final text, its effective date and any change from the committee document. [BE_FOD_12_EN] [BE_FOD_28] [BE_DOC_003]
The compliance file should retain the opening and closing dates, the calendar version used, the relevant administrative notice and, after publication, the exact law reference. Responsibilities may be replanned, but data gathering should not stop. The proposal does not establish a payment deferral, neutralise review procedures or dispense with a complete and internally consistent return. [BE_FOD_12_EN] [BE_DOC_003]
Atypical fiscal years, evidence and limits
The proposed filing period is measured from the year end, while eligibility for the eighteen-month transition depends on the year’s opening date. For a non-calendar year, those two points must be captured separately. A merger, liquidation, change of accounting date or short year may require a specific analysis. An administrative example should not be transposed without checking the actual dates and the scope of the relevant obligation. [BE_FOD_12_EN] [BE_DOC_003]
This analysis is based on the official notices of 28 September and 12 October 2026 and the complete committee-adopted text of 2 October, reviewed on 13 October. It does not confirm enactment of an unpublished law or calculate an identified group’s deadline. Targeted searches of official Belgian judicial domains did not identify a decision directly addressing this very recent proposed change; that result does not establish a general absence of Pillar Two case law. [BE_FOD_12_EN] [BE_FOD_28] [BE_DOC_003]