G1/25: What are the consequences?

Following the release of G1/25, questions have been circling as to what the decision means for the pending referral in G 1/26 and what the consequences (good or bad) are for applicants and patentees. On G1/26, some of the questions have been answered, but arguably only because the EBA considers these questions already answered by G1/24. With respect to the consequences of G1/25 per se, this Kat finds herself (not for the first time...) out of step with the initial consensus. However, a closer reading of G1/25 has only strengthened this Kat’s view that G1/25 is not to be welcomed by applicants or patentees. 

Legal background: Claim interpretation and description amendments

G1/24 held that the description and drawings shall always be consulted to interpret the claims (IPKat). Following G1/24, the Boards of Appeal were left with the task of interpreting what “consulting” the description actually entails. Various approaches have so far emerged, including consult but never broaden and/or narrow (IPKat), or a “holistic” approach permitting both broadening and narrowing (IPKat).

There were subsequently two new referrals, G1/25 (description amendments) and G1/26 (claim interpretation and added matter). Given what G1/25 says about G1/24 (IPKat), it arguably answers some of the questions in G1/26.

G1/26: Claim interpretation and added matter

In T 0873/24, the referring decision in G 1/26, the granted claim in question specified a titanium to nitrogen ratio “in excess of 3.42” without saying what kind of ratio it meant. Read on the claim alone, the term covered every ratio making technical sense to the skilled reader. This interpretation was considered by the Board of Appeal to add matter. The description on the other hand gave the figure by weight, potentially removing the added matter issue. 

The Board of Appeal therefore thought it pertinent to ask the EBA for some clarification and referred three questions. There has been some debate as to whether G1/25 has now already answered one or more of these questions.

G1/26 Question 1: Admissibility

Question 1 of G1/26 is an admissibility question, asking when an EBA decision may be considered “required” in order to ensure uniform application of the law, or if a point of law of fundamental importance, and thereby justify a referral. G 1/25 does not provide a view.

G1/26 Question 2: How should the description be used to interpret the claims

Question 2(a) asks whether starting with the claims as the basis for assessing patentabiltiy, "precludes a feature which is only disclosed in the description or the drawings of a patent from being read into the meaning of a granted claim, in particular if this leads to a restrictive reading of terms used in the claim". This question is answered to some degree in G1/25. R.10 holds that the skilled person “will try to take a definition found in the description at face value”, reading the claim term in that sense “taking into account both the broadening and limiting aspects” (r. 10, emphasis added). Question 2(a) is therefore answered in the negative. The primacy of the claims does not rule out narrowing features from the description being read into the meaning of the claim in general. 

The Board of Appeal approach in T 439/22 (originally an outlying decision) is therefore supported by the EBA (IPKat). Interestingly, this case is also the case that found that description amendments can extend protection from an added matter standpoint.

Consequential dominos? 

Question 2(b) first asks whether reading the claims and description is a unitary process, or whether the claims are read first. This first limb of Question 2(b) is clearly answered in G 1/25. According to the EBA there are no "different stages of interpretation" (r.9). 

Question 2(b) of G1/26 then asks whether the claim being the starting point and the basis for assessing patentability rules out only those interpretations which can be derived from the patent as a whole but would clearly contradict the general technical understanding of the terms used in the claim. On this point, the EBA found that description and drawings “cannot be used to impose on the claim a limitation or expansion for which the claim wording provides no basis” (r. 10, emphasis added). This would seem to imply that the description cannot be used to change the meaning of terms used in the claims to something other than their normal definition. We are, however, now left wondering what “no basis” means. In particular, is “no basis” meant merely to exclude new or unusual definitions (unusual parameters), or to exclude any departure from the normal meaning of the words used in the claims? Or does “no basis” mean that the interpretation must be clear and unambiguous to a skilled person from the claim language?

For the referring case in G1/26, the question thus becomes whether “in excess of 3.42” provides a basis in the claim wording for reading in “by weight”. On one view a bare ratio is meaningless without units, so the claim wording itself calls for units to be supplied and the description does no more than supply them. By contrast, the view could be taken that “by weight” is a limitation for which the claim does not provide clear and unambiguous basis, that r. 10 of G1/25 forbids reading such a limitation into the claim, and that the claim as it stands adds matter.

G1/26: The added matter questions

Question 3(a) of G 1/26 asks whether, when assessing compliance with Article 123(2) EPC, a claim term must be tested against every interpretation that makes technical sense to the skilled reader on the basis of the claim alone. Question 3(b) asks, if it need not, whether it is enough that only those interpretations arrived at against the background of the specification as a whole are directly and unambiguously derivable from the application as filed. In this Kat’s view, these questions are unanswered, or at the very least not yet clearly answered by G1/25. Interestingly, these questions recall the guidance sent to Examiner's on application of G1/24, which requires searches to be carried out on all the possible interpretations of the claim, implying that the EPO's current view is that alternative interpretations must be taken into account in some respect (IPKat). 

Why G1/25 is bad for applicants and patentees

Since G 1/25 was issued last week, there has been much debate over whether G1//25 will make the description adaptation requirement worse or better for applicants and patentees. This Kat is of the view that it has made things worse (IPKat).

First, the risk that a description amendment is itself the invalidity ground has been reinforced in view of Article 123(2) EPC and Article 123(3) EPC. In T 439/22 the deletion of a definition of “gathered” from the description was held to extend the protection conferred, leaving the patentee in an inescapable added matter trap (IPKat). G1/25 establishes that the description can be used to narrow claim language. If you delete a narrowing definition, even at the invitation of the Examining Division, G1/25 confirms that the deletion is capable of broadening the granted claim. It also arguably makes that outcome more likely. This Kat is therefore at a loss as to why anyone would voluntarily make amendments to the description in view of this risk, reasoned or otherwise (unless at a last ditch attempt at trying to cover a competitor product with amendment by the back-door, see Ensygnia v Shell ([2023] EWHC 1495 (Pat)), IPKat).

Description amendments are also now more consequential post-grant. Any amendment will be seized on by opponents as altering claim interpretation, and patentees will therefore need to be prepared to defend each one from an added matter attack.

We can also expect that description amendments will be brought up in litigation in the form of file wrapper estoppel. The UPC Court of Appeal in VusionGroup v Hanshow notably declined to rule out prosecution history as an aid to construction. Description amendments will therefore likely be cited as influential on intended claim scope.

G1/25 may also have an impact even beyond Europe. In the US, claim interpretation takes account of the description and the prosecution history, including what amendments were made and what arguments were submitted, and the file wrapper does not stop at the US border. In K-fee v Nespresso (Case No. 22-2042, Fed. Cir., 26 December 2023) the Federal Circuit treated statements the Patentee had made about the meaning of “barcode” in EPO opposition proceedings as properly part of the material for construing the corresponding US claims (IPKat).

Therefore, if you care about IP strategy beyond the formalities of examination and if you care about more than just Europe, G1/25 is not good for applicants and patentees. G1/25 may, reduce the formalities admin burden of description amendments at the Rule 71(3) stage, but at the price that any amendments that are made, or even not made, may now be given more weight with respect to claim interpretation post-grant. 

What does G 1/25 actually mean for description amendments?

There also remains some debate as to whether G1/25 will actually make adaptation of the description a less onerous requirement for applicants in view of Article 84 EPC.

G1/25 confirms that Article 84 EPC can be used as the basis for an adaptation of the description. Article 84 EPC states that “The claims shall define the matter for which protection is sought. They shall be clear and concise and be supported by the description.” 

Established case law to date has been that the claims must be clear in themselves for a person skilled in the art with common general knowledge of the technical field in question, without the need to refer to the description. However, G1/25 does not follow this path. The decisions taking that view, the EBA says, “proceed on the basis that Article 84 EPC concerns only the claims and that clarity must be assessed without reference to the description”, and to the extent that premise excludes the interpretative role of the description recognised in G 1/24, “it cannot be followed” (r. 29). The principles of G1/24 instead “apply where the assessment under Article 84 EPC requires the meaning of the claims to be determined” (r. 33).

As such, G1/25 may rescue applicants caught between added matter and clarity, because a definition sitting in the description can now be used to make a claim term clear (so “catastrophic comma loss” is less of a risk). On the other hand, the description can now directly be used by the Examining Division as the basis of a clarity objection.

R.20 of G 1/25, which many commentators have pointed to as supporting a more lenient description amendment requirement, states:

“An inconsistency is not established merely because the description, including any drawings, contains a technical teaching, examples, or embodiments that do not fall within the claimed subject-matter.” (r. 20)

So far so good. However, the same paragraph then goes on to say:

“If, on the other hand, due to such an incompatibility, it is unclear whether a technical teaching, examples, or embodiments do, or do not fall within the claimed subject matter, an inconsistency exists.” (r. 20).  R. 35 then provides that where it is “unclear whether information, examples, subject-matter or embodiments are or are not within the scope of the claim, then it cannot be said that the claim is supported by the description” (r. 35), i.e. they offend Article 84 EPC.

Importantly, r. 35 cannot be read as a free-standing licence to demand deletions. It opens with the words “applying the above-defined concept of inconsistency”, which places it downstream of r. 18 to 20 and means that it presupposes an inconsistency already established. However, r. 20 and r. 35 both ask the same question of whether it is unclear that matter falls inside or outside the claim, once to establish the inconsistency and once to decide on Article 84 EPC. As such, the two-step test that commentators have taken from G1/25, inconsistency first and non-compliance with an EPC provision second, therefore can be said to collapse into a single step whenever the provision relied on is Article 84 EPC.

Final thoughts

For this Kat, at the heart of G1/25 is the question of not only how we think a skilled person understands terms used in the art, but how we think a skilled person reads and understands a patent document. After all, all of the discussion presupposes that a skilled person can navigate and understand the distinction between the claims and description, which are themselves artificial creations of patent law. A skilled person reading a patent would also see the abstract, and as a scientist used to reading journal articles, may get very confused by this. However, there is no legal basis for the patent abstract leading to a lack of clarity or thereby needing amendment.

Following G1/25, it seems that everything on claim interpretation now depends on what counts as “basis” for a limitation or expansion. Mandatory description adaptation now arguably depends, inter alia, on when it is “unclear” whether an embodiment falls within the scope of the claim. However, neither term is defined and we wait to see what the Boards of Appeal, and Examiners, will do. In the meantime, applicants and patentees should take extra care with any description amendments and any arguments made in relation thereto. Any position taken for or against description amendments is now potential material on the file that an opponent or a defendant will be more than happy to cite.

Further reading

• Don’t shoot yourself in the foot: European file history in US patent claim interpretation (K-fee v Nespresso) (January 2024)
• No back-pedaling on prosecution disclaimers (Azurity v. Alkem, Fed. Cir. Case No. 23-1977) (April 2025)
• EBA decides G1/24 on claim interpretation: The description should always be consulted (June 2025)
• BREAKING: Referral on description amendments finally confirmed! (G1/25 - “Hydroponics”) (July 2025)
• Divergence between the UPC and EPO on claim interpretation and description definitions (Agfa v Gucci, UPC_CFI_278/2023) (August 2025)
• Description amendments can extend protection (T 439/22) (February 2026)
• New referral on claim interpretation and relevance of G1/24 to added matter confirmed (G1/26) (June 2026)
• Claim construction checkpoints: Application as filed versus granted patent (T 0715/24) (August 2026)
• BREAKING: When real doubt hits - G1/25 changes the description adaptation requirement for the worse (September 2026)