Abstract on Article 069 EPC for the decision T0847/24 of 25.03.2026

In T 847/24 the board addressed the principles of claim interpretation endorsed by the Enlarged Board in G 1/24. The first principle was that the claims were the starting point and the basis for assessing the patentability of an invention. The board understood this as a recognition that the claims defined the claimed subject-matter and that it was the claims themselves which were being interpreted. Accordingly, the claims, on the one hand, and the description and the drawings, on the other, were not on the same footing. This understanding of the significance to be given to the claims aligned with Art. 69 EPC (see T 1473/19), the wording and principles of which the Enlarged Board appeared to consider applicable by analogy. It was also consistent with the Enlarged Board's statement that this first principle of claim interpretation was a settled point in the case law of the boards.

The second principle endorsed by the Enlarged Board was that the description and drawings had to always be consulted to interpret the claims, and not only if the person skilled in the art found a claim to be unclear or ambiguous when read in isolation. According to the board, it followed from this that, without prejudice to the requirement under Art. 84 EPC that claims had to be clear in themselves, a claim should not be read in isolation. In other words, the meaning of a claim and its features was not to be determined in the abstract or on the basis of the skilled person's common general knowledge alone, but in the specific context in which it was used, which included the description and the drawings (as well as other claims). Such consultation could have an impact on the result of the interpretation. This impact was not limited to merely defining the person skilled in the art for the purposes of claim interpretation (see T 439/22).

The board noted that the above understanding of G 1/24 conformed with the Enlarged Board's reference to the harmonisation philosophy behind the EPC and its aim of preventing the EPO from adopting a practice of claim interpretation which would be contrary to the practice of the national courts of EPC contracting states and the UPC. It also fitted seamlessly with the direct applicability of Art. 69(1) EPC and the Protocol thereto in proceedings before the EPO when interpreting a claim to assess compliance with Art. 123(3) EPC.

The board pointed out that determining a patent claim's subject-matter, i.e. establishing the meaning of the claimed features, was not distinguishable from interpreting that claim and its features (see T 1473/19), and that the terms in a given patent claim had to be interpreted in a uniform, consistent and objective manner (see T 1345/23, T 177/22, and T 1473/19). It followed that the same claim interpretation step which, in accordance with G 1/24, had to be carried out when assessing e.g. novelty also had, for reasons of consistency, to be carried out when e.g. assessing added subject-matter, sufficiency of disclosure or extension of protection. This also aligned with the UPC Court of Appeal's statement in its order of 26 February 2024 in NanoString Technologies v. 10x Genomics, UPC_CoA_335/2023, according to which the "principles for the interpretation of a patent claim apply equally to the assessment of the infringement and the validity of a European patent", the term "validity" not being limited to "patentability" under Art. 52 to 57 EPC.

According to the board, the requirement "to interpret patent claims" pursuant to G 1/24 implied that the correct interpretation of a claim could not, if decisive for the outcome, be left open. As to a possible lack of clarity or ambiguity in a claim, this could, as such, only be addressed under Art. 84 EPC, which is not a ground for opposition. Such a deficiency could not be invoked indirectly under a different legal provision not concerned with this issue, such as Art. 123(2) or (3) EPC. A lack of clarity can have ramifications for how the deciding body interprets the claim under consideration and determines the claimed subject-matter, which may in turn have an impact on the outcome of the assessment of a ground for opposition under Art. 100 EPC. However, adopting e.g. a broad interpretation had to be distinguished from leaving the interpretation open or adopting two mutually exclusive claim interpretations simultaneously (see T 367/20).