How to read a patent claim? The Enlarged Board of Appeal of the European Patent Office addressed this fundamental question in its decision G 1/24 from 18. June 2025 answered - and thus ended a long inconsistent practice.

The decision

To date, some boards of appeal have only used the description, if the claim itself was unclear. They always took others into account. The Enlarged Board of Appeal has now clarified: When examining patentability the description and drawings always to be used to interpret the claims - not just then, if the expert considers a claim, viewed in isolation, to be unclear or ambiguous. The wording of the claims remains decisive; the description serves as an aid to interpretation.

Approaching the courts

This brings the practice of the EPO into line with the interpretation of the infringement courts: The Federal Court of Justice has always interpreted patents using descriptions and drawings, and the Unified Patent Court has also taken this approach since its first appeal decision. A patent is therefore granted- and appeal proceedings and later in court are increasingly understood in the same way.

What does that mean for you??

• Formulate description carefully: Definitions and explanations in the description can expand or restrict the scope of protection - for better or for worse.
• Avoid contradictions: If the description differs from the wording of the claim, This can be used against you in an appeal or in court.
• Open follow-up questions: Whether and to what extent the description needs to be adapted to changing requirements, hat G 1/24 not decided. This question continues to concern the Boards of Appeal.

Our patent attorneys pay attention to the Drafting your patent application on it, that the claims and description fit together and are valid in the office and in court.

Those: EPA, Große Beschwerdekammer, Decision v. 18.06.2025, G 1/24 (epo.org). General overview, no legal advice in individual cases. Stand: November 2026.