As we approach the Oral Proceedings for the much-anticipated G 1/25 referral, we consider the preliminary, non‑binding opinion of the Enlarged Board of Appeal (EBoA) and assess whether the distinctly European practice of amending the description to align with amended claims is likely to remain.
The practice of amending the description during proceedings before the European Patent Office (EPO) often involves deleting, or modifying, embodiments that fall outside the scope of the amended claims. However, this is not clear-cut for every embodiment, and some may be partially or arguably encompassed by the amended claims. In addition, amendments to the description can, in some cases, result in new combinations of features that were not originally disclosed, raising potential added-matter issues. Furthermore, in some instances, description amendments may affect post-grant proceedings before national courts or the Unified Patent Court (UPC).
For these reasons, applicants are often hesitant to amend the description of their application during prosecution, or their granted patent during opposition and opposition-appeal proceedings.
Questions have therefore been raised as to whether such amendments are in fact required under the European Patent Convention (EPC), leading to the interlocutory decision T 0697/22 and the G 1/25 referral to the EBoA.
In response to the questions referred to the Board, the EBoA provided the following preliminary, non-binding observations:
Q1. 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?
Observation: Yes, if the inconsistency results in non-compliance with the EPC. If the inconsistency does not result in non-compliance with the EPC, then amendment of the description is not required.
Q2. If the first question is answered in the affirmative, which requirement(s) of the EPC necessitate(s) such an adaptation?
Observation: Article 84 EPC appears to require amendment of the description.
Q3. 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?
Observation: No. There should be no distinction between examination and opposition proceedings.
Regarding the observations to Q1, it is notable that the EBoA acknowledged that certain inconsistencies may exist between the claims and the description without resulting in non-compliance with the EPC. However, no examples or specific guidance were provided in the preliminary opinion as to what types of inconsistencies might fall within this category. This leaves open the possibility that the EBoA may recognise limited circumstances in which patentees can avoid amending the description, even where inconsistencies arise during proceedings.
With respect to Q2, the EBoA took the view that Article 84 EPC provides a legal basis for requiring amendments to the description and rejected the contrary line of case law cited in the referring decision (T 1989/18, T 1444/20, T 2194/19 and T 56/21). That case law was based on a literal interpretation of Article 84 EPC, under which the requirement that the claims be “supported by the description” merely prohibits claims to unsupported subject-matter.
The EBoA further concluded that this line of case law was inconsistent with the reasoning provided in the recent decision G 1/24. However, the preliminary opinion does not elaborate as to why this literal interpretation of Article 84 EPC was considered irreconcilable with G 1/24.
By way of reminder, the EBoA held in decision G 1/24 (see our reports here and here) that the description should always be consulted when determining the patentability of the claims, thereby establishing an interpretative link between the claims and the description in proceedings before the EPO.
In our view, this consultative link may be the reason why the EBoA considers G 1/24 as supporting a requirement to amend the description: if the claims and description are inherently linked for interpretation, amendments to the claims would necessitate corresponding amendments to the description. To ensure consistency, it seems unlikely that the EBoA will reverse this position.
The requirement to amend the description appears likely to stay, although we will only know for certain when the EBoA issue their decision in the months following the Oral Proceedings.
Philip Horler and Bradley Wilson
This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.
© Withers & Rogers LLP May 2026
