Preliminary opinion on description amendments issued by the Enlarged Board of Appeal in G 1/25
The Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) has now issued its preliminary opinion in G 1/25 (“Hydroponics”).
The referral, which we commented on previously, stems from the decision issued by the Board of Appeal (BoA) in T 697/22 and seeks to resolve divergent case law by clarifying whether, and on what legal basis, the description of a European patent application must be amended for consistency with the claims.
Per current EPO practice, applicants are indeed required to amend the description for consistency with the claims, for example by amending or deleting embodiments no longer covered by the claims. However, decisions of the BoA have questioned whether the European Patent Convention (EPC) provides legal basis for this requirement. The EPO is the only major patent office to have such a requirement.
The questions of the referral and comments provided in response by the EBA in the preliminary opinion are summarised as follows:
1) If the claims of a European patent are amended during opposition proceedings or opposition-appeal proceedings, and the amendment introduces an inconsistency between the amended claims and the description of the patent, is it necessary, to comply with the requirements of the EPC, to adapt the description to the amended claims so as to remove the inconsistency?
The preliminary opinion of the EBA considers only two types of inconsistencies: those that do and do not lead to non-compliance with the EPC. Only inconsistencies leading to non-compliance would require amendment of the description and/or claims.
2) If the first question is answered in the affirmative, which requirement(s) of the EPC necessitate(s) such an adaptation?
Though the EBA notes that adaptation of the description is required no matter which relevant EPC provision is not complied with, it indicates a preference for the line of case law that is derived from Article 84 EPC, which provides that: “The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.”
The EBA refers to its recent decision in G 1/24 (also commented on by us here), emphasising that the description must be consulted when interpreting the claims, seemingly to ensure consistency for the purposes of coherent claim interpretation.
3) Would the answer to questions 1 and 2 be different if the claims of a European patent application are amended during examination proceedings or examination-appeal proceedings, and the amendment introduces an inconsistency between the amended claims and the description of the patent application?
The EBA appears to see no reason to distinguish between examination and opposition proceedings in the context of the referral, indicating that the same principles apply in either scenario.
Overall, although the opinion is preliminary and contains limited reasoning, it suggests that the EBA may ultimately confirm the EPO’s established practice of requiring adaptation of the description.
Oral proceedings are scheduled for 8 May 2026. The final decision is expected to provide long-awaited guidance on the extent to which the description must be adapted in line with the claims in European patent proceedings.
If you wish to seek advice on how to manage issues relating to description amendments at the EPO, please contact your usual Barker Brettell attorney or the authors of this article, Laura Riggall and Jennifer Atkinson.
