On 3 September 2025, the Enlarged Board of Appeal (EBA) of the EPO issued its decision G 01/25 (the ‘Hydroponie’ case) concerning the need to adapt the description, an issue which has recently given rise to much debate, both within the EPO and amongst practitioners.
Two conflicting lines of case law had in fact coexisted within the EPO. According to the first line of case law, there is a legal basis within the EPC requiring the description to be consistent with the amended claims. According to the second line of case law, there is no legal basis for rejecting a patent application in the event of inconsistency between amended claims and the description, caused by the amendment of the claims. In particular, according to this second line of case law, Article 84 of the EPC does not provide such a legal basis.
Following considerations on the relevance of its earlier decision G 01/24 to this case and on the interpretation of Article 84 EPC, the Enlarged Board of Appeal of the EPO provides a definition of inconsistency: there is an inconsistency between the claims and the description, as well as any drawings, where one or more indications in the description, including the drawings, suggest an interpretation of a claim that is incompatible with the apparent meaning of that claim, and where that incompatibility cannot be readily resolved by applying the principles set out in decision G 1/24.
The Enlarged Board of Appeal concludes in its decision that it is necessary to amend the description and/or the drawings only where an amendment to the claims results in an inconsistency between the amended claims and the description and/or the drawings which leads to non-compliance with a requirement of the EPC (Articles 52 to 57, 76(1), 83, 84, 123(2) and 123(3)).
The Enlarged Board of Appeal of the EPO further confirms that where an inconsistency arises but does not result in non-compliance with a requirement of the EPC, it is not necessary to amend the description or the drawings, whether during examination, opposition or appeal proceedings. This position therefore clarifies the approach to be adopted towards the EPO when filing amended claims during proceedings.