Belgium opens Pillar Two filing portal days before deadline

Belgian tax authorities opened the MyMinfin portal for GloBE Information Return submissions on June 29, 2026, leaving roughly two days before the unchanged June 30 deadline and turning Pillar Two compliance into a last-mile filing problem for groups with Belgian entities. KPMG flagged the timing on June 26, and the practical issue was not the tax rule itself but whether companies could get into the system, load the right data, and submit before the clock ran out.

MyMinfin is the Belgian Federal Public Service Finance’s secure online portal for tax and financial matters, which made the late opening especially consequential for multinational groups trying to line up internal approvals. For KPMG tax teams, the immediate checklist was operational: confirm which entity would file, make sure the GIR data set was complete, map the return template correctly, and clear sign-off across finance, tax, and legal before submission. When the portal itself arrives days before the deadline, the bottleneck moves from policy interpretation to coordination.

Belgium had already pushed several Pillar Two milestones back. On April 3, 2026, the authorities extended the first QDMTT and IIR filing deadlines to September 30, 2026. On June 12, they extended the GIR notification deadline to September 30 as well and said the notification portal would open on July 1. Deloitte said that notification covered the entity that would file the GIR for in-scope multinational and large domestic groups, while EY said groups using the notification portal would have to wait until July 1 to access it.

The filing mechanics were not simple even with more time. KPMG said Belgium had already made technical documentation available, including the XSD schema and two Belgium-specific validation rules, and that taxpayers could use a simulation portal through MyMinfin to test filings. Belgium also published a draft IIR return template and guidance on March 19, 2026, along with an addendum to the Pillar Two Circular Letter on currency conversions, which meant taxpayers had been working from evolving draft materials rather than a settled electronic process.

The timing mattered beyond Belgium. The OECD said calendar-year multinational groups had to meet the June 30, 2026 deadline for the 2024 GIR, and EY noted that groups centrally filing in one of the jurisdictions listed in the OECD annex might avoid adverse consequences for not filing locally in jurisdictions that had joined the common understanding. For KPMG practitioners, the Belgian filing window was a reminder that Pillar Two is now a delivery exercise as much as a tax calculation, and that the weakest local portal can still determine whether a global filing lands on time.