Dutch tax authority hid 64 million documents in secret data vault

In April 2024 a hidden “data vault” containing about 64 million files was uncovered at the Dutch Tax Administration (Belastingdienst). An investigation by BDO concluded the vault was created in 2019 to keep outdated or potentially non‑compliant data out of view, including extensive records related to the childcare‑allowance fraud scheme. The sheltering of the files meant that two parliamentary investigation committees were denied access to material they were legally required to receive, breaching the Constitution and the law governing parliamentary inquiries.

BDO’s review, based on 29 interviews, contradicts earlier statements by state secretaries that the vault was discovered by accident and that a software error caused the omission. The report says the tax office deliberately concealed the data to avoid GDPR fines and to manage archive‑law obligations, while still sharing some of the information with other government bodies and banks. The finding raises questions about the tax authority’s handling of the broader “toeslagenaffaire” and its compliance with privacy and archival regulations.