G1/25 – The EPO ponders: are description amendments really necessary?
On 29 July 2025 the European Patent Office’s (EPO) Technical Board of Appeal 3.3.02 made the first referral of 2025 to the EPO’s Enlarged Board of Appeal on the question of the need to amend the description to bring it in line with the claims. The referral resulted from interlocutory decision T 697/22, which considers a patent granted to Knauf Insulation (EP2124521).
The referral addresses whether there is a requirement under the European Patent Convention to adapt the description to eliminate any inconsistencies when claims are amended during opposition proceedings, when such claim amendments introduce an inconsistency between the claims and the description. The EPO’s current practice can be found in its Guidelines for Examination, Part F, Chapter IV, Section 4.3. Since these requirements place an additional burden on patent applicants and their European attorneys, they have been unpopular with many practitioners and have reared their head in many decisions of the EPO’s Boards of Appeal. For example, recent Technical Board of Appeal decision T 56/21 stated that there is no legal basis for requiring that the description be adapted to match allowable claims of more limited subject-matter, however the EPO’s Guidelines were not amended following that decision, and the EPO’s practice did not change.
Three questions were put forward after the opponent (Rockwool International A/S) argued that amended claim 1 was no longer consistent with the claims, in that amended claim 1 included a feature that is compulsory, but the description described the feature as being optional, and thus an inconsistency had been introduced. The Board of Appeal agreed with the opponent’s argument in section 10.5 of its decision.
The Board of Appeal noted that there is no legal requirement for the description to be adapted, despite there being a number of decisions citing Article 84 EPC as requirement the description to be amended. Thus, the following questions were referred to the Enlarged Board of Appeal:
- 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?
- If the first question is answered in the affirmative, which requirement(s) of the EPC necessitate(s) such an adaptation?
- 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 reason why the first question relates to post-grant opposition proceedings is that the appeal in suit resulted from an opposition, consequently question three extends to the context of examination proceedings.
A sequel to G1/24?
As previously discussed, it was determined in G1/24 that the description and drawings must always be consulted when interpreting the claims. This is highly relevant to G1/25, indeed the referring Board of Appeal made multiple references to it. The decision from G1/24 prompted worries as to how inconsistencies between the claims and the description would affect claim interpretation. This will, hopefully, be cleared up, once and for all, in the decision of G1/25, which we will await with bated breath.
