State Secretary for Finance Eelco Eerenberg told the House of Representatives in a letter that the Netherlands Tax and Customs Administration has abandoned its planned Microsoft 365 cloud migration. Email and calendars move to on-premises infrastructure in 2027, with storage and collaboration services following later in 2027 and 2028 on European open-source alternatives. The move covers the tax authority, customs and the benefits service; the roughly 5,000 employees already migrated to Microsoft 365 stay on it for now.
The decision follows a June recommendation from the Dutch Advisory Board on ICT Assessment to roll back the cloud rollout rather than complete it as planned by end-2026. The board found the chosen Microsoft 365 design “falls short on information security, information processing and future-proofing,” citing confidential documents traversing American servers, metadata aggregation risks, reliance on standard Microsoft encryption instead of double-key encryption giving the administration control, and backups that “fall seriously short.”
The reversal is notable because the administration selected Microsoft 365 in 2025 precisely because no European alternative was thought to meet its requirements; officials now say increased internal data center capacity makes the on-premises route viable. It is part of the Dutch government’s wider push for a digitally autonomous government work environment, which has already put a Windows-to-NixOS migration on the table.