Referral G1/25 – Does the description need to be adapted?

A new referral has been submitted to the Enlarged Board of Appeal (EBoA) of the EPO concerning adaptation of the description to correspond to amended claims. This was indeed to be expected, following the recent decision G1/24 (see our news item on decision G1/24 here), as according to this decision, the description is always to be used for interpretation of the claims.

Basis and grounds of the referral

In the decision T397/22 which is the basis for this referral, the adaption of the description became relevant in a situation where the opposition division had accepted into the proceedings a new auxiliary set of claims that was filed during oral proceedings. Also the board of appeal was of the opinion that the decision to accept the set of claims into the proceedings was correct, and thus this set of claims was also part of the appeal proceedings.

The patentee had filed also an amended description during the opposition proceedings. The opponent submitted that the description was however in conflict with the amended claims, i.e. contradicting Article 84 EPC. Article 84 EPC says, i.a., that the claims must be supported by the description. In the present case, claim 1 had been limited with respect to a certain feature, making it a mandatory feature, while in the amended description, this feature was still presented as optional. The board of appel agreed with the opponent, i.e. that there was an inconsistency between the claims and the description.

According to the board of appeal, if such an inconsistency between amended claims and the description is contrary to Article 84 EPC, the conclusion is that the amended set of claims and the amended description are not allowable. In the opposite case, they are allowable.

Thereafter, the board of appeal researched previous decisions of boards of appeal on this question, and concluded that they were divided in two groups. The decisions consulted included also decisions on appeals from application proceedings. A majority of the decisions concluded that it was necessary to adapt the description to correspond to amended claims. In these decisions, there were however five different lines of arguments as to the legal basis in the EPC and its Implementing provisions. A minority of the decisions which arrived at a conclusion that there is no need for such an adaption were all recent and taken in examination appeals. There exists thus a basis for the referral, due to the diverging case law.

Questions asked

The referral asks the following questions.

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?

Does the referral already have an impact on proceedings?

An affirmative answer to the above questions would have a significant impact on prosecution. If the decision was affirmative and the EPO would adopt a strict view on the issue, the patentee would need to ensure that every time they file an amended set of claims, they would also file a correspondingly amended description. Correspondingly, an applicant should, at the latest at the grant phase, ensure that the description corresponds to the claims, if amended during prosecution of the application.

Otherwise, it is possible that a board of appeal would decide that a lack of adapted description is something that can no longer be corrected in appeal proceedings, unless it is done immediately when filing the first brief (grounds of appeal or reply to appeal). A board that applies the rules of procedure of the boards of appeal strictly can even decide that if the amended set of claims was already pending in the first instance proceedings, filing of a correspondingly amended description only during appeal is too late and thus not allowed.

This is what actually happened in the case at hand. Before the oral proceedings in front of the boards of appeal, the patentee was of the opinion that it was not necessary to further adapt the description, in order to make it correspond to the set of claims in question, even though there was an inconsistency between the description and the claims. During oral proceedings, the patentee however submitted a new, amended description that corresponded to the amended set of claims.

The opponent argued that this adapted description should not be admitted into the proceedings as being late filed. Additionally, the opponent submitted that the amended description constituted an amendment of the patentee’s case and it should not be admitted into the proceedings also on this ground. The board of appeal agreed with this latter view, and did thus not admit the amended description into the proceedings.

Should the decision be affirmative, it is possible that it is applied also retroactively, at least in boards of appeal. It might thus be wise to take this referral into account also in pending opposition proceedings.

On the other hand, a local division of the Unified Patent Court (UPC) has in April 2025 handled a case, in which the UPC decided that the claims limited during prosecution of the application and the description were not in line with each other. According to the UPC, this is not allowed, and the patentee was not allowed to refer to the description and to try to expand the scope of protection of the claims in this manner. The patent was however held in force in the granted form, despite this inconsistency between the claims and the description, i.e. this kind of unallowed issue did not invalidate the patent. Should this become the general view of the UPC, it is comforting for the patentee to know that even if the EPO changes their view in that the description must be adapted to the amended claims, this would not have an effect of the validity of the patent, at least not retroactively and in front of the UPC.

Author’s guess on the answer to the referral

In my opinion a decision stating that the description does not need to be adapted to amended claims would be in contradiction with the recent decision G1/24.

Personally, I hope that the EBoA decides that adaptation is necessary. One can of course argue many ways on this issue, but the situation in infringement proceedings would be clearer, if the patentee could not refer to the description to try and expand the scope of protection from to what it was previously limited to. A description adapted to amended claims would thus also increase third parties’ legal certainty.

Within a year we will most probably know the view of the EBoA on this question.

G1/24: https://www.epo.org/en/boards-of-appeal/decisions/g240001ex1

T697/22: https://www.epo.org/en/boards-of-appeal/decisions/t220697ex1