2026 EPO Guidelines: Applying G1/24

The EPO Enlarged Board of Appeal’s 2025 decision, G1/24, established that the description of a patent or application must always be consulted when determining patentability of the claims. See our earlier summary here. Clearly this has significant impact on examination, opposition, and search proceedings. The 2026 EPO Guidelines revision includes extensive changes, spanning sections on clarity, interpretation and more, concerning the construction of claims for the purpose of assessing patentability. 

Clarity (GL 2026, F-IV, 4.1)

The idea that claim clarity is of the utmost importance has been expanded on.

It was stated in the G1/24 decision that Art. 84 EPC is formal in nature and does not mention the invention (paragraph 8). Despite this analysis, a renewed focus on clarity was invited by the decision overall. The latest version of the Guidelines spells out that the reason why clarity is so important is for “legal certainty”. 

As well as claims leaving no room for doubt as to which category they occupy, there should likewise be “no doubt as to which subject-matter is covered by the claims”. This criterion is elaborated with reference to the skilled person, who should be able to establish the scope of the claim without undue burden. This choice of language echoes that which is already used to help define the related concept of sufficiency from Art. 83 EPC: “…the application must contain […] sufficient information to allow the skilled person, using common general knowledge, to perform the invention over the whole area claimed without undue burden…” (GL 2025, F-III-1, 1). The “delicate balance” between claim clarity and sufficiency of disclosure, too, is already acknowledged in the Guidelines, where a serious lack of clarity can snowball into insufficiency (GL 2025, F-III-11, 11). Thus the new Guidelines not only warn against such an outcome by invoking the sufficiency concept within the clarity section, but also actively borrow an element of a sufficiency test for practical use in establishing clarity. 

It is stipulated that “the correct response to any lack of clarity in a claim is amendment”, faithfully following the wording of G1/24 (paragraph 20), in which the Enlarged Board highlighted the importance of the examining division carrying out a high quality examination on this statutory requirement. Indeed, even before examination begins in earnest, partial searching, potentially resulting from a serious lack of clarity, may have the knock-on effect of the scope of claims needing to be restricted by amendment (R. 63(1), (3) EPC). 

Search (GL 2026, B-III, 3.2)

The subsection on the interpretation of claims by the search division has been updated to adhere to the principles of G1/24. 

The search, though already not restricted to the literal wording of the claims, is now to be done in a way where the description and any drawings are always consulted. This could provide applicants and their representatives with reassurance that their claims will be given a holistic interpretation from the outset. It is also possible that any supposed clarity issues will start to surface earlier during prosecution, which practitioners will want to be prepared for.

Interpretation (GL 2026, F-IV, 4.2)

The subsection on claim interpretation is now headed up by the precedent set in decision G1/24: “the claims are the starting point”, and “the description and any drawings are always referred to”, not only if there is ambiguity in the claims. 

This revision, in turn, appears to cement the realignment of European claim interpretation for the determination of patentability with the sentiment of both Art. 69 EPC (“The extent of the protection conferred by a European patent […] shall be determined by the claims…”) and its Protocol on Interpretation (“Article 69 should not be interpreted as meaning that the extent of the protection conferred by a European patent is to be understood as that defined by the strict, literal meaning of wording used in the claims, the description and drawings being employed only for the purpose of resolving an ambiguity…”), albeit these sources as such are distinguished in the decision due to concerning purely infringement matters (paragraph 7, G1/24). 

The influence of the decision is bounded in this update, though – “when assessing patentability, the description and drawings cannot be relied on to read into the claim a restrictive feature not suggested by the wording of the claim”. This seems to chime naturally with the expansive approach taken by the search division, but what about in examination?  The new approach is further defined: if the description broadens the claims, the claim must be interpreted in that broader light, provided the interpretation is “technically meaningful”. Although these two interpretative approaches may seem to contradict one another, they do at least appear to align with long-standing case law, which advocates conferring a “broadest technically sensible meaning” on the claims (CLBoA I-C, 4.1; e.g. T 79/96, T 596/96). 

It is now evident that the normal meaning of terms in the art is still relevant, but takes a lesser place than the specification itself when interpreting the claims. 

Relative terms (GL 2026, F-IV, 4.6)

There is a theme throughout these subsections on the use of the whole application as a resource for resolving claim uncertainties.

Claim interpretation, informed by a trio of description, drawings, and “well-recognised meaning in the particular art”, is carried out before finding that there is a lack of clarity (consistent with paragraph 17, G1/24). Only where a relative term (such as “thin”, “wide”…) remains unclear after a comprehensive reading should there be a clarity objection raised. Examples, including one illustrating that the term “elastic” is generally non-limiting, have been removed, which could signify the start of a more generous treatment of relative terms in claims during European examination. 

Broad claims (GL 2026, F-IV, 4.22)

Last but not least – elements of practice relating to discrepancies between claims and the description have actually been softened in this revision. 

“Where there are discrepancies between the claims and the description, the claims may not be supported by the description”, instead of this being a foregone conclusion. Even very broad claims may still be allowable if the invention is “sufficiently disclosed over the whole of the broad field” recited in the claim. Whether these points will noticeably dial down the overall need for description amendments in prosecution is yet to be seen – and, of course, the Enlarged Board may decide to change practice when G1/25 is decided.