In its decision G 1/25, the Enlarged Board of Appeal (EBA) of the European Patent Office (EPO) has provided guidance on a contentious issue in EPO practice: when amendments to claims require corresponding amendments to the description.
The decision follows closely on the heels of G 1/24 (see our previous articles here, here and here) and addresses two important issues.
Firstly, G 1/25 clarifies that adaptation of the description is not required merely because a patent specification contains embodiments that fall outside the scope of the claims purely for the sake of formal concordance. Instead, adaptation is only necessary where an inconsistency between the claims and the description or drawings gives rise to non-compliance with the EPC.
Secondly, the EBA endorses the “holistic” approach to claim interpretation adopted in the Board of Appeal decision T 439/22 when applying G 1/24, under which the claims, description and drawings are read together as part of a single interpretative exercise.
Not every unclaimed embodiment requires amendment
The central issue referred to the EBA concerned whether an amendment to the claims necessarily requires corresponding amendment of the description whenever the amended claims no longer encompass all disclosed embodiments.
The EBA rejected the view that every inconsistency between the claims and the description must automatically be removed. On the other hand, it also rejected the proposition that such inconsistencies are always irrelevant under the EPC. Instead, the Board held that the key question is whether the inconsistency has legal significance because it results in non-compliance with a substantive EPC requirement.
In defining what constitutes an inconsistency, the EBA introduced an important qualification. An inconsistency exists where statements in the description suggest an understanding of a claim that is incompatible with its apparent meaning, and that incompatibility cannot readily be resolved by applying the claim interpretation principles established in G 1/24. The decisive question is whether the skilled person would be left in real doubt as to the meaning of the claim.
Crucially, the EBA stated (r.20) that an inconsistency is not established merely because the description contains technical teachings, examples or embodiments that fall outside the claimed subject matter. An inconsistency arises only where it is unclear whether those teachings or embodiments do or do not fall within the scope of the claims.
While we will need to wait to see how the Examining Divisions and Boards of Appeal apply G 1/25, this distinction may have significant practical consequences. For example, consider a claim that expressly requires a DC power source while the description includes an unclaimed embodiment employing an AC power source. Under the approach frequently adopted by the EPO in recent years, applicants were often required to amend or qualify such embodiments because they no longer fell within the claims. Following G 1/25, there may now be a stronger argument that no amendment should be required in such circumstances, because it is immediately apparent that the AC embodiment falls outside the scope of the claims and there is no uncertainty as to claim scope because the skilled person would immediately understand that an AC power source falls outside a claim expressly limited to a DC power source.
By contrast, where the description creates uncertainty as to whether a particular embodiment falls within the claims, whether the claims encompass known or obvious subject-matter, suggests a different interpretation of a claim feature, or otherwise casts doubt on the meaning of the claims, an inconsistency may arise that requires amendment. The EBA explained (r.35) that where it is unclear whether information, examples, subject-matter or embodiments are, or are not, within the scope of the claims, it cannot be said that the claims are supported by the description. In such circumstances, the inconsistency may result in non-compliance with Article 84 EPC and therefore require amendment.
A further endorsement of the post-G 1/24 approach to claim interpretation
Although G 1/25 is primarily concerned with description amendment, its comments on claim interpretation may prove equally significant.
The EBA reiterated the position of G 1/24, which established that the description and drawings must always be consulted when interpreting claims. Perhaps more significantly, G 1/25 expressly endorses the reasoning subsequently adopted in T 439/22, describing claim interpretation as a “unitary” or “holistic” process in which the claims, description and drawings are read together from the outset. The Board rejected (r.8) the notion that claim wording should first be construed in isolation and that the description should only be considered if ambiguity remains.
This is noteworthy because T 439/22 was regarded by many as one of the more expansive applications of G 1/24. In that case, the Board relied upon a definition contained in the description when interpreting the claim term “gathered sheet”. The definition broadened the meaning that might otherwise have been attributed to the term, ultimately resulting in the claims being found to lack novelty. By approving the approach taken in T 439/22, the EBA appears to have confirmed that express definitions in a patent specification may significantly influence claim interpretation.
The decision therefore serves as a reminder that applicants should take considerable care when drafting definitions and explanatory statements in the description. Following G 1/24 and G 1/25, it may be increasingly difficult to argue that such statements should be disregarded when determining claim meaning.
Practical implications
While we will need to wait to see how it is applied in practice, G 1/25 may reduce the extent of description amendment required during examination and opposition proceedings. The EBA has expressly stated that the EPC does not require adaptation of the description “merely for the sake of formal concordance”. Applicants may therefore find it easier to retain clearly unclaimed embodiments where those embodiments do not create uncertainty regarding claim scope or otherwise affect compliance with the EPC.
At the same time, the decision strengthens the role of the description in claim interpretation. By endorsing T 439/22 and reaffirming the principles established in G 1/24, the EBA has made clear that the description and drawings form an integral part of claim interpretation.
Viewed together, G 1/24 and G 1/25 suggest a subtle shift in EPO practice. We may now see less focus on achieving formal alignment between the claims and the description, but greater focus on whether statements in the specification could affect how the skilled person understands the claims.
Rhodri Kendrick
This publication is a general summary of the law. It should not replace legal advice tailored to your specific circumstances.
© Withers & Rogers LLP September 2026
