FATCA Before the CJEU: A Key Procedural Step in Belgium

An important procedural development has taken place in Belgium in a case concerning the application of the U.S. tax regime (FATCA), which requires Belgian financial institutions to identify certain clients and to transmit banking information to the Belgian tax authority, which then forwards it to the U.S. tax administration, with the aim of combating tax evasion. 

This mechanism has raised data protection concerns for several years, in particular for so-called “Accidental Americans”. The Accidental Americans Association of Belgium (AAA) intervened in this case. In 2023, the Belgian Data Protection Authority found that certain data processing and transfers linked to FATCA were not compliant with the GDPR. The Belgian State lodged an appeal against that finding.

By a judgment rendered in November 2025, the Brussels Market Court decided to stay the proceedings and to refer thirteen preliminary questions to the Court of Justice of the European Union, in particular concerning the interaction between an international tax agreement and the GDPR, the proportionality of the processing, the legality of transfers to the United States in the absence of an adequacy decision, and the respect for fundamental rights.

The future decision of the CJEU will provide important clarifications on the compatibility of international tax data-exchange mechanisms with EU data protection law.
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