Belgium's top court has resolved a major tax dispute by ruling that the subscription tax on collective investment institutions sits outside the Belgian-Luxembourg Double Taxation Treaty, eliminating a potential 1.5 billion euro liability for the state and allowing the government to proceed with taxing Luxembourg-based funds.
The United Chambers of Belgium’s Court of Cassation has reversed earlier decisions from the Brussels Court of Appeal, clearing the way for Belgium to tax foreign investment institutions, according to an update published by Belgium’s government on 7 September 2026.
The ruling concerned four separate appeals over the Annual Tax on Collective Investment Institutions, commonly referred to as the subscription tax.
Treaty scope narrowed
The Brussels Court of Appeal had ruled on 25 April 2023 that the subscription tax fell within the material scope of the Belgian-Luxembourg Double Taxation Treaty, effectively shielding Luxembourg collective investment institutions from the levy. The Court of Cassation’s decision repudiates this interpretation. The court determined that the tax operates outside the treaty’s scope, allowing Belgium to assess the charge against Luxembourg-based funds without violating bilateral tax agreements.
Substantial fiscal relief
The Brussels Court of Appeal rulings had exposed the Belgian State to potentially 1.5 billion euros in repayments to Luxembourg investment institutions. The Court of Cassation ruling substantially reduces this exposure and resolves a significant budgetary risk. The Finance Public Service (FPS Finance) signalled that the decision confirms the government’s longstanding position on how the tax should function within the treaty framework.
Implications for tax case law
The judgment carries broader significance for Belgian tax jurisprudence on international treaties and collective investment vehicles.
The Finance Public Service (FPS) indicated it would examine the full decision and maintain its defence of state revenue within established legal boundaries and certainty principles.
