Yesterday, the Enlarged Board of Appeal issued their decision on case G1/24 regarding how patent claims must be interpreted when assessing patentability. This decision concluded that:
“The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC. The description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention under Articles 52 to 57 EPC, and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation.”
Overall, the decision sets out a pragmatic approach to claim interpretation that should help to unify the approach taken by the EPO with that taken by the UPC and national courts and lead to better legal certainty for all parties involved in patent litigation by providing a more consistent approach between EPO patentability and enforcement both nationally and at the UPC.
Key practice points
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At the drafting stage, include accurate definitions in the description of any terms that may be ambiguous.
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Be mindful when defining terms in a way that diverges from common general knowledge to help avoid inadvertently bringing additional prior art into consideration or unduly narrowing the scope of protection available.
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The decision doesn’t change the need to carefully consider amendments made to the description.
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When construing a claim, always take the description and drawings into account.
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When attacking a claim, consider whether there are any contradictions between the claims and the disclosure in the description that may be used to your advantage.
Background
The referral originates from the EPO Technical Board of Appeal decision T439/22, concerning a patent for ‘heat-not-burn' tobacco products. A key issue in the appeal was the interpretation of the term "gathered sheet" used in claim 1. The referring Board found that if this term is given its usual meaning in the art, the claims are novel over the cited prior art. However, if the term is construed in light of the description, the term takes on a broader (but still technically sensible) meaning and claim 1 lacks novelty.
The Board considered case law to be divergent on how patent claims should be interpreted, and therefore referred three questions to the Enlarged Boards of Appeal:
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Is Article 69(1), second sentence, EPC and Article 1 of the Protocol on the Interpretation of Article 69 EPC to be applied to the interpretation of patent claims when assessing the patentability of an invention under Articles 52 to 57 EPC?
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May the description and figures be consulted when interpreting the claims to assess patentability and, if so, may this be done generally or only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation?
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May a definition or similar information on a term used in the claims which is explicitly given in the description be disregarded when interpreting the claims to assess patentability and, if so, under what conditions?
Reasons for the decision
Turning to Question 1, the Enlarged Board concluded that Article 69 EPC and the Protocol are only concerned with infringement actions before national courts and the UPC, while Article 84 EPC provides no guidance on how to interpret claims. Thus, there is no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability.
When considering Question 2, the Enlarged Board noted that the following principles could still be extracted from existing case law because the legal basis for the claim interpretation did not affect the principles that were applied:
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The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC.
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The description and any drawings are always referred to when interpreting the claims, and not just in the case of unclarity or ambiguity.
An important factor in reaching this decision appears to be harmonisation with the practice of the national courts and the UPC, with the Enlarged Board specifically noting that their interpretation is consistent with current case law of the UPC, as exemplified in NanoString Technologies -v- 10x Genomics. This hints towards a desire to ensure a unified European patent law practice.
A decision was not reached on Question 3 since the Enlarged Board considered it to be encompassed within Question 2, and thus inadmissible.
Finally, the Enlarged Board commented that this decision highlights the importance of the Examining Division ensuring the granted claims are clear, presumably to limit the possibility of diverging claim interpretations in different jurisdictions post-grant (a point raised in the Comments of the President of the EPO).
Looking forward
It is clear that the description and drawings will play an important role in claim interpretation from now on. One situation this decision didn’t address was what should be done when there is a contradiction between the claims and the description. Therefore, it will be interesting to see how this decision will be applied to these cases in the future.
If you would like to hear more, we will be running a Fast Response webinar on 26 June 2026 – sign up here.
For more background information, see our articles discussing the case that led to the referral and the referred questions.
If you have any questions relating to this topic, please get in touch with Sophie Evans, Bethany Myers or your usual Kilburn & Strode advisor.