The Netherlands’ Tax and Customs Administration has abandoned its planned Microsoft 365 public-cloud rollout.
The drive toward an open-source, digital sovereignty approach continues across Europe. At the Open Source Summit Europe conference, the Linux Foundation released the 2026 State of Open Source in Europe, revealing that 94% of European Union organizations say digital sovereignty is important, with 61% considering it very important.
The Netherlands had planned to switch to Microsoft 365 in 2025, with rollout completion by end of 2026. About 5,000 employees had already migrated when the Dutch Advisory Council on ICT Assessment recommended reversing the public-cloud rollout in June. The government paused the plan in July; the latest announcement replaces that rollout with an on-premises/open-source approach.
The Tax and Customs Administration isn’t replacing all of Microsoft Office with a single open-source suite, at least not yet. Instead, the government will keep the existing Microsoft software for now.
State Secretary for Finance Eelco Eerenberg set out the replacement timetable in a letter to Parliament: “In 2027, the provision for mail and calendar will be realized on-premises. Later in 2027 and 2028, European open-source solutions for personal storage and collaboration will follow.”
The ICT assessment found that the chosen Microsoft 365 public-cloud design fell short on “information security, information processing and future-proofing.” Concerns included confidential documents on American servers, standard vs. Double Key Encryption, Teams end-to-end encryption limitations, vendor lock-in, digital sovereignty, and lack of an adequate exit strategy.
Other Dutch government agencies have started developing Digitaal Autonome Werkomgeving Overheid (DAWO). DAWO starts by replacing the Windows desktop with the Dutch Linux distribution NixOS. France’s La Suite and Germany’s openDesk are being considered; MijnBureau (Nextcloud, Collabora, Element, OpenProject) is another option.