Decision G 1/24 on Claim Interpretation is out

The Enlarged Board of Appeal has issued its decision in case G 1/24 (“Heated aerosol”) on 18 June 2025, providing clarification on the interpretation of patent claims when assessing patentability. The Enlarged Board has confirmed that the claims are the starting point and the basis for assessing the patentability of an invention under Articles 52 to 57 EPC, and that 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.

The decision arose from a referral in case T 439/22, which concerned a patent for a vaping device. A central issue in the case was whether the term “gathered sheet” should be interpreted strictly based on its general technical meaning or whether the definition provided in the patent description should be applied. The outcome of the case hinged on this interpretation, raising broader questions about whether the principles of Article 69 EPC and its Protocol, typically applied in infringement proceedings, or Article 84 should also govern claim interpretation during the patentability assessment.

In its reasoning, the Enlarged Board acknowledged that while the EPC does not explicitly provide a clear legal basis for claim interpretation when assessing patentability (see Point 9 of the Decision), the practice of reading the claims in conjunction with the description and drawings is the correct approach. The Enlarged Board held that neither the Protocol on the Interpretation of Article 69 EPC nor Article 84 EPC forms the legal basis for claim interpretation in this context and that what matters is the established approach by the Boards of Appeal of considering the claims, description, and drawings together when assessing patentability, without needing to base this on the Protocol or Article 84 EPC.

The Enlarged Board firmly rejected the case law of the Boards that sees no need to refer to the description and drawings when interpreting a claim, unless the claim is unclear or ambiguous. It emphasized that excluding them would contradict both the wording and principles of Article 69 EPC as well as established national case law and the practice of the UPC. In this regard, the Enlarged Board held that it would be undesirable for the EPO to intentionally apply a practice that contradicts that of the national courts responsible for the enforcement of its patents.

The full decision can be accessed here.

epi had submitted an amicus curiae brief on the referred questions back in November 2024 which can be seen here. The Institute also submitted additional comments supplementing the amicus curiae brief in February 2025 which can be see here.

The decision broadly follows the position expressed by epi in its amicus curiae brief, particularly in supporting the approach that the description and drawings must be consulted generally when interpreting the claims and not only if the person skilled in the art finds a claim to be unclear or ambiguous when read in isolation.