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.

We are pleased to share that our firm Prüfer & Partner together with six of our intellectual property attorneys have been recognized for their outstanding work in patent prosecution and nullity in the newly published 2025 Edition of IAM Patent 1000, one of the world’s leading rankings with regard to patent services providers. We are very proud and honored that our next generation managing partners Dr. Susanne Sonnenhauser and Dr. Christian Gärtner were also listed for the first time.

What the ranking said
Prüfer & Partner
“A reliable firm providing quality patent prosecution advice…appreciated for their responsiveness, cost-effective approach and overall excellent client service.”

Jürgen Feldmeier
“Jürgen Feldmeier is a responsive and highly professional practitioner with a deep understanding of his clients’ technologies. This means he provides careful and accurate opinions, as well as valuable advice on patent applications and portfolio management, and defence strategies that are tailored exactly to his customers’ needs.”

Dr. Dorothea Hofer
“Dorothea Hofer has the ability to understand complex technical matters and provide the appropriate advice. She is a great attorney, capable of dealing with urgent matters through putting together strong teams to tackle important cases.”

Dr. Andreas Oser
“Andreas Oser carefully drafts patent applications and provides helpful advice on handling proceedings at the patent office. He devises cost-efficient strategies, highlighting the risks and challenges of each option, and selecting the most suitable path depending on his clients’ needs.”

Markus Adamczyk
“Markus Adamczyk, a dual-qualified patent attorney and attorney-at-law, sees issues from every angle to dispense valuable holistic counsel. He works seamlessly with his clients to masterfully protect and enforce their rights.”

Dr. Susanne Sonnenhauser
“Susanne Sonnenhauser is adept at working with groundbreaking technologies and companies whose patents are central to their success; unflappable under pressure, she operates with precision and the utmost care at each turn.”

Dr. Christian Gärtner
“Christian Gärtner is an impressive strategist who devotes his practice to achieving meaningful patent protection for his clients. He gets to know their businesses incredibly well and tailors his advice to suit their needs.”

About IAM Patent 1000
The prestigious ranking IAM Patent 1000, published by Globe Business Media Group in London, is commonly regarded as the definitive ‘go-to’ resource for those seeking to identify world-class, private practice patent expertise as well as leading patent service providers. IAM undertook an exhaustive qualitative research project to identify outstanding firms and individuals across multiple jurisdictions. When identifying the leading firms, factors such as depth of knowledge, market presence, and the level of work on which they are typically instructed were all taken into account, as well as positive peer and client feedback.