Schleswig-Holstein Ditches Microsoft: €15M Saved

In December 2025, the German state of Schleswig-Holstein confirmed what its digital ministry had been building toward since 2021: 80% of government workstations are now running LibreOffice, 44,000 mailboxes have been migrated from Microsoft Exchange to Open-Xchange with Thunderbird, and the state projects €15 million in annual savings starting 2026. The total one-time migration investment was €9 million — meaning the payback period is under one year.

This is the largest active government migration away from Microsoft in Europe, and the most closely watched since Munich's LiMux project. Unlike LiMux, which was reversed in 2017 after political winds shifted, Schleswig-Holstein's migration has cross-party support and a full software stack replacement rather than a piecemeal switchover.

Key Takeaways

• €15M saved annually — the state paid approximately €500/employee/year for Microsoft Office 365 across ~30,000 employees; that cost goes to zero
• €9M one-time investment to complete the migration — payback in under 12 months
• 44,000 mailboxes migrated from Exchange to Open-Xchange + Thunderbird by October 2, 2025
• Full stack replaced: Office → LibreOffice, Exchange → Open-Xchange, Outlook → Thunderbird, SharePoint → Nextcloud, Teams → Jitsi/OpenTalk, AD → Univention, Windows → Linux (KDE)
• 2027 target for full Windows-to-Linux desktop migration across eligible departments
• Real challenges documented: judiciary, police union, and employees experienced disruption during the email migration; the Digital Minister issued a written apology in mid-2025

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Why Schleswig-Holstein Did This

The stated rationale has two components: cost and sovereignty.

Cost is straightforward. ~30,000 state employees at €500/year per Microsoft license equals €15 million flowing to Redmond annually. That's a recurring cost for software the state doesn't control, can't audit, and can't modify.

Sovereignty is the harder argument to quantify. German state governments operate under the EU's data protection framework (GDPR) and face increasing scrutiny over US Cloud Act exposure — American law that allows US authorities to compel Microsoft to hand over data stored anywhere in the world, including on EU servers. Open-source software running on German servers eliminates that legal ambiguity. After the 2024 US-EU political tensions around data localization, this framing resonated across party lines.

Schleswig-Holstein's Digital Minister Dirk Schrödter (CDU) — notably a conservative politician, not a left-wing open-source ideologue — has been the public face of the migration. Cross-party support distinguishes this from Munich's LiMux, where the project became politicized after a mayoral change.

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The Full Software Stack Replacement

ODF became the official document standard in August 2024 — a foundational prerequisite before LibreOffice deployment, since it eliminates the need to save in .docx format for interoperability.

The state's IT service provider Dataport is managing the rollout. Dataport handles IT for multiple northern German states, which means the migration tooling and lessons learned will benefit neighboring state governments.

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The Timeline

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The Challenges (Documented Honestly)

This migration has not been frictionless. The challenges are worth understanding because they're the same ones any large organization faces.

The judiciary reported being unable to access emails at critical moments — including during time-sensitive matters like arrest applications and house searches. This isn't a minor UX inconvenience; it's a legitimate operational failure that the ministry acknowledged.

The police union (GdP) described conditions in the Interior Ministry as "chaos" during August 2025. Planned migration steps were cancelled or postponed on short notice without adequate communication to staff.

The Digital Minister's apology: Dirk Schrödter issued a written letter to state employees acknowledging "stressful weeks and the problems that have arisen." That's an unusual level of transparency for a government project — and it's the right move. It kept employee trust intact rather than letting resentment fester.

Remaining 20%: The last fifth of workstations are held up by specific technical dependencies: SAP integration, specialized vertical applications, and the tax administration (managed on a separate timeline by the state finance ministry).

External critics at the Center for Data Innovation (June 2025) argued the decision was politically motivated and that hidden costs were underestimated: employee training at ~€1,600/person, testing consuming 60% of conversion costs, and ongoing support burden. They also raised WTO procurement questions.

The state's data protection commissioner Marit Hansen urged slowing the pace and coordinating with other states rather than acting as a solo pioneer — not opposition to the goal, but concern about execution speed.

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The Munich LiMux Comparison (And Why This Is Different)

Munich's LiMux migration (2004–2017) is the obvious reference point — and the cautionary tale the Schleswig-Holstein team is clearly aware of.

Munich migrated ~14,800 of 15,500 desktops to Linux by 2013, saving an estimated €11 million. Then in 2017, a new CDU/SPD coalition reversed the project, with all desktops back on Windows 10 by 2020. Official reasons: employee dissatisfaction, software incompatibility, inadequate training.

Most independent analyses concluded the failure was organizational, not technical. Insufficient change management, running parallel systems instead of fully committing, and a hostile new political administration all contributed. (Some observers also noted that Siemens and Microsoft's Munich headquarters proximity to the decision-making didn't help.)

What Schleswig-Holstein is doing differently:

1. Full replacement, not hybrid — no "keep Microsoft for power users" carve-outs that undermine adoption
2. ODF-first document standard — eliminates the daily friction of format conversion
3. Cross-party political commitment — CDU leadership means it survives a change in governing coalition
4. 2026-era software — LibreOffice, Thunderbird, and Nextcloud are dramatically more mature than their 2004 equivalents
5. Explicit digital sovereignty framing — a policy argument that resonates with conservative and progressive politicians alike in post-2024 geopolitics

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The French Gendarmerie: The Long-Term Success Story

For proof that large-scale government Linux deployments can succeed long-term, look at France's Gendarmerie.

Beginning in 2005, the Gendarmerie deployed a custom Ubuntu distribution called GendBuntu across its entire computer fleet. By the time Schleswig-Holstein was announcing its migration plans, GendBuntu was running on over 97% of the Gendarmerie's 103,000 computers. The most recent upgrade — to GendBuntu 24.04 LTS — was completed in December 2024.

That's 20 years of continuous operation, upgrades, and maintenance of a large-scale open-source Linux deployment in a law enforcement environment with real security requirements. It's the counterexample to every "this can't work in government" objection.

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What €15M in Annual Savings Looks Like

€15 million per year is not the full financial picture — there are real costs on the other side:

Savings:

• €15M/year in Microsoft Office 365 licenses eliminated
• Reduced Windows licensing costs as the Linux rollout completes in 2027
• Exchange Server licensing eliminated (replaced by Open-Xchange)

Costs:

• €9M one-time 2026 investment for infrastructure completion
• Training: estimates range from €200–€1,600/employee; at €500 average for 30,000 employees, that's €15M — roughly one year's savings
• Ongoing support and customization (Dataport staff, internal IT, partner ecosystem)
• Compatibility work for remaining 20% with SAP/specialized app dependencies

Net picture: Even with generous estimates for hidden costs, the annual €15M saving compounds significantly over time. By year 3, the state will have cleared all transition costs and be in a position of pure savings.

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What Other Organizations Can Learn

Schleswig-Holstein's migration offers practical lessons for any enterprise considering a move away from Microsoft:

1. Lead with ODF before LibreOffice. Setting the document standard first removes the daily interoperability pain before users even touch the new software. If everyone's still saving as .docx, LibreOffice feels broken even when it isn't.

2. Email is the hardest part. The messaging and email migration caused the most disruption. Build in more buffer time, over-communicate the timeline, and have rollback procedures ready for critical users (judiciary, emergency services).

3. Don't create carve-outs. "Power users keep Microsoft" creates a two-tier organization that undermines adoption. The holdouts (20% with SAP/specialized apps) exist for genuine technical reasons, not personal preference — that's an acceptable exception. Preference-based exceptions are not.

4. Change management is the project. Technical deployment is the easy part. The Gendarmerie succeeded over 20 years; Munich failed after 13 years. Both had similar technical stacks. The difference was organizational commitment.

5. €9M for 30,000 employees = €300/employee. As a benchmark for migration investment, that's a useful data point for any organization modeling a similar transition.

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The Broader European Context

Schleswig-Holstein is not acting in isolation. Several European governments are actively reducing Microsoft dependency:

• France: The Gendarmerie (103K desktops), plus DINUM (French digital ministry) promoting open-source tooling across government
• Germany: Bavaria and other states watching Schleswig-Holstein's progress; Germany's federal Sovereign Workplace (Souveräner Arbeitsplatz) initiative pushing toward EU-hosted alternatives
• EU institutions: The European Commission uses Signal for secure messaging; growing internal pressure toward EU-hosted cloud services
• Netherlands, Denmark, Austria: Various departments and municipalities at different stages of Microsoft reduction

The EU's Cyber Resilience Act and AI Act are adding regulatory pressure on software supply chains that makes open-source auditable software more attractive to compliance officers across the continent.

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The Document Format Question

One underappreciated aspect of the Schleswig-Holstein migration is the ODF-first mandate. By declaring Open Document Format the official standard in August 2024 — before rolling out LibreOffice widely — the state eliminated the daily interoperability friction that killed LibreOffice adoption in other migrations.

When employees save documents as .docx (the Microsoft default), LibreOffice becomes a second-class citizen — it opens the files, but the formatting sometimes shifts, and employees always feel like they're on the "wrong" tool. When ODF is the mandated format and everyone uses it, LibreOffice is the primary tool and Microsoft compatibility is the edge case (handled by "export to DOCX" when needed).

The sequence matters: document standard first, software second. This is the lesson most enterprise open-source deployments miss.

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What This Means for Organizations Evaluating a Switch

The €15M annual saving is headline-grabbing, but the more replicable insight is the total cost picture:

• €9M one-time transition investment for 30,000 employees = €300/employee. At many organizations, a single Microsoft Enterprise Agreement renewal costs more than that per user per year.
• Hidden costs are real: training at ~€500–€1,600/employee, partner/consultant costs for specialized integrations, and ongoing internal IT load. Budget for 1.5–2x the software licensing savings in year-one transition costs.
• Year-3 economics: After migration costs are absorbed, the annual saving is pure margin. At €15M/year, year 3 represents €30M+ of cumulative savings over the migration investment.

For private-sector organizations: the same math applies at smaller scale. A 500-employee company paying €500/user/year for Microsoft 365 (€250,000/year) could execute a similar migration for €150,000–300,000 one-time cost and zero annual licensing thereafter.

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Schleswig-Holstein's migration is a living experiment. It's messy, it's real, and it's producing verifiable cost data. For organizations considering their own Microsoft exit, the key lesson is that the obstacles are organizational — not technical. The software exists. The will has to follow.

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Browse all open-source enterprise alternatives at OSSAlt. Related: Nextcloud vs Google Workspace migration guide, self-hosted email options.