Claim interpretation is at the core of patent law, as it defines the scope of protection and thus the extent of exclusive rights granted.
The Enlarged Boards of Appeal (EBA) recently issued the long-awaited decision in case G1/24, addressing the fundamental question of how claims should be interpreted before the EPO. The decision, published on 18th June 2025, concluded that the description and drawings shall always be consulted to interpret the claims when assessing the patentability of an invention, and not only if the skilled person finds a claim to be unclear or ambiguous when read in isolation.
The decision was based on the following three questions.
- 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 Article 52 to 57 EPC?
- 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?
- 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?
Decision
The EBA held that both questions 1 and 2 address points of law of fundamental importance and therefore were considered as admissible. Question 3 was considered to be encompassed within Question 2 and as a result was inadmissible as a separate question.
The EBA acknowledged that neither Article 69 EPC and Article 1 of the Protocol, nor Article 84 EPC provide a fully satisfactory legal basis for claim interpretation when assessing patentability. The Board thus concluded that there is no clear legal basis, in terms of an article of the EPC, for claim interpretation when assessing patentability.
On review of how the Boards of Appeal have interpreted patent claims when assessing patentability, the following principles of claim interpretation were extracted:
1) The claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC.
2) The description and any drawings are always referred to when interpreting the claims, and not just in the case of unclarity or ambiguity.
The EBA highlighted that diverging case law, where the description is referred to only in cases of unclarity or ambiguity, is contrary to the wording, and hence the principles, of Article 69 EPC, and to the practice of the national courts of the EPC states and the UPC.
The EBA highlighted that this decision aligns the EPO claim interpretation with the national courts of the EPC states and the UPC.
What does this mean?
The Decision aims to provide more certainty. It underscores the importance of high-quality patent drafting of entire patent specifications, not just the claim, as inconsistent definitions or information provided in the description may impact the scope of the protection. Furthermore, any amendments made to the description during prosecution, including those requested by the EPO Examiner at grant stages, should be carefully considered.
It remains to be seen if the Decision will lead to more extensive requirements to adapt the description in line with the claims.
The full Decision can be found here.
Please note that this article is for information purposes only and should not be taken as legal advice. Please contact your regular PURDYLUCEY contact if you have any questions.