New Guidelines for Claim Interpretation
The decision G1/24 of the Enlarged Board of Appeal of the European Patent Office (EPO) could mark a turning point in how patent claims must be interpreted when assessing the patentability of the subject-matter of the claims.
However, although this decision provides important clarification on the subject and helps harmonize EPO practice with that of national courts, it does not constitute a definitive solution. Instead, it offers a chiaroscuro that highlights the claims in relation to the description.
Overview of G1/24
The Enlarged Board of Appeal was asked to determine the extent to which the description (and drawings) of a patent should be taken into account when interpreting the claims in discussions relating to patentability. As recalled in the decision, Article 69 EPC and its Protocol on Interpretation relate to the extent of protection, so that they may be invoked in principle in infringement discussions, but not in those concerning patentability.
Decision G1/24, issued on 18 June 2025 and published in OJ EPO 2025, A60, essentially states that the wording of the claims constitutes the basis for assessing patentability. It further specifies that the description and drawings must be consulted to interpret the claims in this assessment of patentability, regardless of any clarity issues or ambiguities that the skilled person might encounter when reading the claims. The Enlarged Board nevertheless points out that the description is not intended to restrict or broaden the meaning of the claims when these are clear.
It will be up to the Boards of Appeal to apply the new practice established by decision G1/24. Although the latter is relatively recent, decisions have already begun to apply it. We comment on some below.
Assessment of the First Decisions Applying G1/24
In case T2027/23, the Board of Appeal relied on G1/24 to examine a claim whose wording did not appear to present any problem of clarity or ambiguity. The patent description contained examples not included in the claims and allowing for a more restrictive interpretation of the claims. The Board held that these examples did not need to be taken into account to interpret the scope of the claim, and simply consulted the description to determine the nature of the skilled person. This decision illustrates the priority given to the claim wording over the description, as indicated in the summary of the decision provided by the Board: “a claim is not to be interpreted, on the basis of features stated in the embodiments of an invention, as having a meaning more restrictive than the claim wording as understood by the skilled person.”
In case T1849/23, the Board was confronted with a claim whose scope was disputed in light of the description. Relying on G1/24, it refused to interpret the claim literally—although it was unambiguous—on the grounds that the description disclosed a single embodiment that was not covered by the literal interpretation of the claim. The Board thus interpreted the claim in light of the description so as to include the described embodiment within its scope, which led to a reversal in the debate on the novelty of the claimed subject-matter.
Decision T1561/23 presents the opposite situation: the claim contained formulations that were open to several possible interpretations. The applicant relied on decision G1/24 to interpret these formulations on the basis of embodiments provided in the description. The Board replied that the description did not give a definition of the formulations in question, but only illustrative examples, which did not justify a narrow interpretation of the claim wording (convenient for patentability). As a result, the principle of G1/24 did not apply in this case.
In case T1999/23, the patent contained a discrepancy between the claim and the description, using a term with an established definition in the technical field in the claim, and an unusual limitation in the description. Referring to G1/24, the Board considered that although claims must be interpreted in light of the description, there is no apparent justification for departing from a well-established and unambiguous definition of a term in the claims on the basis of an unusual definition given only in the description. This confirms the primacy of the claim wording over the teaching provided by the description.
What to Take Away from G1/24 and Its Implementation?
It appears from these few decisions that the interpretation of claims in light of the description remains a case-by-case approach, despite the clarifications that were sought when the Enlarged Board was referred the questions that led to decision G1/24.
Nevertheless, it should be noted that interpreting claims on the basis of their wording takes precedence over using the description, and that the latter may be invoked in particular when an ambiguity is present in the claim. Furthermore, one should not expect to rely on decision G1/24 to choose to apply a definition—particularly a restrictive and advantageous one in patentability debates—provided in the description in an attempt to escape a standard definition in the field for a term appearing in the claims. Thus, drafting patent applications must continue to be carried out with attention to consistency between the claims and the description.
Article by Aurélien BARETY, 13 January 2026
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