Preliminary opinion of the EPO Enlarged Board of Appeal, G1/25: Adaptation of the Description

On 11 March 2026, the Enlarged Board of Appeal (EBoA) issued its preliminary opinion in G 1/25, following a referral from case T 0697/22. The case concerns whether, and on what legal basis, the description must be adapted to amended claims during EPO proceedings.

Although preliminary opinions of the EBoA are not binding, but they give a clear indication of their provisional thinking ahead of the oral proceedings.

Oral proceedings are scheduled for 8 May 2026 and will be livestreamed here.

While oral proceedings and a final decision are still pending, it seems that description amendments may be here to stay. A more detailed look at the three questions and preliminary answers is below.

There is still scope for the EBoA to further clarify when an inconsistency (see question 1) causes non-compliance with the EPC and therefore necessitates amendment. We’ll be watching for that further clarification later this year!

Question 1 – When is description adaptation required?

The EBoA distinguishes between:

1. inconsistencies between claims and description that do not cause non‑compliance with the EPC, and

2. inconsistencies that do cause non‑compliance with the EPC.

They only consider the inconsistencies that do cause non-compliance with the EPC to be relevant. Where an inconsistency leads to EPC non‑compliance, the EBoA’s preliminary view is that further amendment of the description and/or the claims is necessary to restore compliance.

Question 2 – Which EPC provisions justify adaptation?

The EBoA explains that adaptation is required by whichever EPC provision is infringed by the inconsistency. While the referral refers to the EPC generally, the opinion focuses on Article 84 EPC.

The EBoA states that it is currently of the view that the established line of case law allowing reliance on Article 84 EPC should be followed.

It expressly distances itself from the approach adopted in T 56/21, which found description amendments to be unnecessary, noting that this approach appears inconsistent with G 1/24 and its underlying reasoning.

Question 3 – Is examination treated differently from opposition?

The Board sees no reason to distinguish between examination and opposition proceedings in the context of this referral. The same principles are considered to apply in both contexts.