Somewhere in a German federal ministry, a civil servant opens a spreadsheet. The file extension reads .xlsx. She has done this thousands of times — it is the default, the thing you never think about. But as of March 18, 2026, that default has an expiry date.

Germany’s IT-Planungsrat — the body where federal and state governments coordinate digital infrastructure — ruled that all German public institutions must switch to ODF for editable documents and PDF for final documents. Microsoft’s .docx, .xlsx, and .pptx are not on the list.

This is not a recommendation. It is not a preference. It is a binding decision that applies to every federal agency, every state government, and every municipality. The scope: roughly 5.4 million public sector employees.

What was actually decided

The format mandate is part of the Deutschland-Stack, the government’s framework for sovereign digital infrastructure. The official specification names the permitted formats explicitly:

  • ODF (ISO/IEC 26300) — for all editable office documents
  • PDF/UA — for accessibility-compliant, non-editable documents
  • JSON, XML, CSV — for data interchange
  • SQL, ODBC, JDBC — for relational data access

OOXML — the format behind .docx, .xlsx, and .pptx — is absent. So are older Microsoft formats. As The Document Foundation summarised: “ODF is not listed as a mere preference or fallback solution, but as a standard document format.”

The timeline: ODF compliance is targeted for 2027, with full Deutschland-Stack infrastructure by 2028.

Why formats are a sovereignty question

A file format seems like a mundane technical detail. But formats determine which software can read, write, and process government data. When a government standardises on a format controlled by a single vendor, it creates a dependency that reaches far deeper than a licence agreement.

Lock-in through defaults. Microsoft Office saves to OOXML by default. Every document created in this format reinforces the assumption that Microsoft Office is required to read it. Over decades, this creates an archive of millions of documents that effectively require one company’s software.

Cost of the status quo. The German federal government spent €204.5 million on Microsoft licences in 2024 — a figure that has been rising year over year. State and municipal spending is estimated to be significantly higher. These costs are not purely for value received; they reflect the price of switching being even higher.

Access to national records. Government documents are public records. If those records are stored in a format whose full specification is controlled by a foreign corporation, the government depends on that corporation to access its own data. ODF, as an ISO standard maintained by an open process, removes that single point of dependency.

Schleswig-Holstein proved it works

This is not untested theory. Schleswig-Holstein has been migrating 30,000 government PCs from Microsoft Office to LibreOffice since 2024. By December 2025, roughly 80 % of the migration was complete.

The numbers: €15 million per year in saved licence costs, against a one-time migration investment of €9 million. Payback period: under one year.

The migration was not without friction — document formatting differences, macro compatibility, and user retraining all required investment. But the state accepted these costs as the price of actual control over its own infrastructure.

The mandate does not exist in isolation. It sits on a stack of legal commitments:

The coalition agreement (April 2025) commits to “open interfaces, open standards, and targeted advancement of Open Source” across all government levels.

The EU Interoperable Europe Act (Regulation 2024/903, in force since April 2024) requires open standards for cross-border interoperability between public administrations. While it does not name ODF explicitly, it mandates vendor-neutral standards — and ODF is the only widely adopted document format that meets this criterion without qualification.

The EU Parliament’s 471-to-68 vote for “Open Source first” in public procurement provides the political framing. Germany is the first major member state to translate this into a binding format requirement.

Europe is watching

France mandated ODF through its Référentiel Général d’Interopérabilité in 2009. The UK followed in 2014. The Netherlands requires ODF for all public sector data exchanges. But in each case, enforcement has been uneven. Italy adopted guidelines that are, by its own digital agency’s admission, “almost always disregarded.”

Germany’s approach is different because the IT-Planungsrat’s decisions are constitutionally binding across all government levels — federal, state, and municipal. The Document Foundation’s open letter to Europe calls on other EU member states to follow suit, arguing that the Interoperable Europe Act already provides the legal basis.

The precedent matters. If the EU’s largest economy makes ODF mandatory and enforceable, it changes the calculus for every European government still defaulting to .docx.

What this is not

This is not an anti-Microsoft article. Microsoft Office supports ODF — imperfectly, but it does. The mandate does not ban Microsoft software; it bans the assumption that Microsoft formats are the default. Institutions can continue using Microsoft Office if they save in ODF. What they cannot do is require other institutions to have Microsoft software to read their files.

The distinction is between choosing a tool and being locked into one.

The line between dependency and control

Somewhere in that German ministry, the civil servant will eventually open her spreadsheet in a different format. She probably will not notice. The columns will look the same. The formulas will work. The file will be slightly smaller.

But the country behind that spreadsheet will have quietly redrawn the line between dependency and control — at the level most people never think about.

Sources

Topic overview: Digital Sovereignty in Europe Related articles: Sovereignty Washing Explained, Linux in the Public Sector