In G 1/24, the EPO’s Enlarged Board of Appeal held that the description and drawings must always be consulted when interpreting claims for the purpose of assessing patentability under articles 52–57 of the European Patent Convention (EPC).
This raised the question as to whether the description and drawings should also always be consulted to assess other requirements such as clarity, sufficiency, and added subject matter.
A recent decision, T 2488/22, sheds light on this question.
The ruling, which was handed down on February 18 2026, concerns an appeal against a first-instance decision that found that the claims of an opposed patent contained added subject matter. The proprietor argued that, following the approach endorsed in G 1/24 in June 2025, the skilled person would consult the description and understand the amended claim in a manner consistent with the disclosed embodiments.
The board’s first catchword states: “The description and drawings should be consulted to interpret the claims not only when assessing patentability under Articles 52 to 57 EPC but also when assessing compliance with other requirements of the EPC. Claims must be interpreted in a consistent and uniform manner when assessing compliance with the EPC.”
This suggests that the description plays a role in claim interpretation beyond the assessment of patentability.
Yet, the board draws an important line with regard to added matter. The decision further states that “if an amended claim is interpreted so that its subject-matter is limited to what can be derived from the application as originally filed, the comparison of this claim to the content of the application as originally filed would inevitably lead to the conclusion that the claimed subject-matter does not extend beyond the content of the application as originally filed”.
This reasoning is captured in the second catchword of the decision: “Limiting the claims based on the description and drawings when such limitations are not derivable from the claims’ wording would deprive Articles 123(2) EPC and 100(c) EPC from their meaning and purpose”.
Hence, T 2488/22 suggests that claims must be interpreted in a consistent and uniform manner when assessing compliance with the requirements of the EPC, but the decision further limits the extent to which this principle should be applied, particularly when assessing added subject matter and when using the description to read unclaimed limitations into the claims.
