Update on the G1/25 Enlarged Board of Appeal referral on description amendments

To recap, the G1/25 referral is derived from T0697/22, involving a patent owned by Knauf Insulation relating to a hydroponics growing medium. The Board of Appeal referred the following questions to the EBA:
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?
2. If the first question is answered in the affirmative, which requirement(s) of the EPC necessitate(s) such an adaptation?
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?

A total of 39 amicus curiae briefs were filed by different companies, practitioners’ associations and legal scholars offering their viewpoints on the above questions. It is interesting to note that a majority of the submissions (29 in total) argue against amendments to the description during opposition proceedings or opposition appeal. The briefs discuss different lines of reasoning to assume this position, from there not being any legal basis in the European Patent Convention (EPC) to procedural economy. Two additional third party observations also arrived in February, as can be seen on the EPO website section under pending referrals to the Enlarged Board.

Notably, recent decision G 1/24 was used in the argumentation of both those in favour of and those against amendments. G 1/24 establishes that the description and drawings must always be consulted when interpreting the claims, and not just in the case of unclarity or ambiguity. For those against amendments, G 1/24 makes it clear that the claims are the starting point and the basis for assessing the patentability of an invention. While for those in favour of amendments, the correct application of G 1/24 means that if the applicant/proprietor wants the different interpretation found in the description to be taken into account, then it is for the applicant/proprietor to amend the claim accordingly.

It is also worth noting that both parties to the proceedings are also against amending the description, whereas the President of the EPO is in favour of said amendments. The President of the EPO argues that the adaptation of the description is essential for legal certainty, harmonisation, and clarity in the European patent system, quoting Article 84 EPC as the main legal basis for requiring this adaptation.

Although the briefs are not legally binding, the EBA will review them before issuing a decision. Oral proceedings for this case have been scheduled to take place on 8 May 2026 at 10:00 hrs, at the EPO offices in Munich. The public and members of the media will be able to follow the proceedings online via livestream. The access link will be published on the EPO website from 30 April 2026. We are awaiting with interest the decision of the Enlarged Board of Appeal to hopefully bring some clarity to such a contested point of law.

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