On June 18, 2025, the Enlarged Board of Appeal of the European Patent Office published its decision in G1/24 (“Heated Aerosol”) – a decision with significant implications for the future interpretation of European patent claims. The guiding principle is clear: claims must always be interpreted in the light of the description and drawings – not only if the wording is unclear (para. 18.).
The EPO is thus fundamentally changing its previous practice and moving closer to the line taken by the Unified Patent Court (UPC) and German courts. The Enlarged Board of Appeal expressly clarifies that an isolated interpretation of the patent claim based purely on the wording – as was advocated in T 169/20, for example – is neither practicable nor desirable.
Starting point: referral T 439/22 – from individual case to system change
The decision was prompted by a referral from the Technical Board of Appeal 3.2.01 (T 439/22). The issue in dispute was whether a definition of a term in the description – in this case the term “gathered sheet” – influences the interpretation of the claim, even if the claim is clearly formulated in terms of language.
The answer of the Enlarged Board of Appeal is clear: Yes, the description must always be used. The “claims-only” approach previously advocated in some cases is now a thing of the past. The EPO is thus committed to a holistic, context-related interpretation – a step towards greater legal certainty and uniformity in Europe.
What does this mean in practice?
The effects for patent applicants and us patent attorneys are immediately noticeable:
– Consistency between description and claims is more important than ever – inconsistencies can have a direct impact on claim interpretation.
– Examination procedures could also change: EPO examiners are likely to analyze claims more in the context of the description in the future.
– Third parties – e.g. competitors – will have new points of attack if the description contains inconsistencies with the claims.
Consequence:
Amendments to the description during examination must be approached with even more care, as inadequate adjustments can quickly lead to problems with Article 123(2) EPC.
Classification in the European context: Alignment with the UPC and national practice
The UPC already follows the now confirmed approach in decisions such as NanoString v. 10x Genomics: Here too, the context of the description is used to interpret the claim – with the aim of achieving a uniform scope of protection in all member states.
German courts also traditionally rely heavily on the description, but often interpret it in light of the technical purpose. The approach is therefore often more function-oriented than the EPO’s previously more text-oriented approach – which can sometimes result in more far-reaching interpretations.
Conclusion:
G1/24 creates a degree of clarity and harmonization here. The decision strengthens harmonization within Europe and improves the predictability of claim interpretation for all parties involved – a welcome step for European patent practice as a whole.
