In T 0837/24 (8 December 2025), the Board considered how far a technically meaningful interpretation of a claim must be taken into account when assessing added subject-matter and extension of protection. The decision is notable for its treatment of claim construction after G 1/24, and for its finding that an inconsistent first-instance decision may amount to “exceptional circumstances” under Article 13(2) RPBA.
Background
The patent (proprietor: GN Hearing A/S; opponent: EPOS Group A/S) concerned a method for providing user-related presence information in a personal communications system comprising a headset and an interface unit. The invention addressed the problem that a user speaking on a mobile or desktop telephone could incorrectly appear available in a softphone presence system.
The opposition division had found that the patent as granted was insufficiently disclosed (Article 100(b) EPC) and maintained it in amended form according to a first auxiliary request. The opponent appealed, seeking revocation.
Claim 1 as maintained required a presence message indicating whether a mobile or desktop telephone was involved in a phone call “with or without using the headset”. This feature had been added to the claim during the examination proceedings. The opponent argued that this wording could mean that the presence message itself contained specific information as to whether the headset was used for the call. On that interpretation, the feature had no basis in the application as filed. The opposition division had not admitted the late-filed objection against the patent as granted, but later stated that the maintained request complied with Article 123(2) EPC for the same reasons. The Board considered this approach inconsistent.
Key findings of the decision
To ensure the parties’ right to be heard, the Board first addressed admittance. It admitted the late-filed Article 123(2) EPC objection into the appeal proceedings based on the “circumstances of the appeal case”. It held that the opponent’s construction was technically meaningful and that the objection was prima facie highly relevant. The parties had also dealt with the issue in full on appeal, and the ambiguity in the opposition division’s reasoning meant the opponent could reasonably have assumed the objection was part of the proceedings.
On claim construction, the proprietor relied on the description, Article 69(1) EPC and G 1/24. It argued that the wording should be read as meaning that the telephone was involved in a call regardless of headset use. The Board accepted that this was a possible interpretation, but not the only one. Reading the claim that way effectively gave no technical meaning to the words “with or without using the headset”. A good-faith interpretation with a “mind willing to understand” should normally give technical meaning to each claim feature. The alternative construction, under which the presence message included specific information on headset use, therefore also had to be considered.
Applying that construction, the Board found added subject-matter. The application as filed disclosed a busy indication being generated irrespective of headset use. It did not directly and unambiguously disclose a presence message containing specific information on whether the headset was used. The main request (as well as auxiliary requests 1 to 5, which suffered from the same issues) was therefore not allowable under Article 123(2) EPC.
With its later auxiliary requests M-A and M-B, the proprietor attempted to remove the problematic meaning. The Board admitted them, holding that a self-contradictory or inconsistent appealed decision may itself constitute “exceptional circumstances” under Article 13(2) RPBA where causally linked to the amendment.
However, the amendments failed under Article 123(3) EPC. The proprietor had argued that removing one of two possible claim interpretations inherently narrowed the scope. The Board disagreed, noting that the amendment removed “not a claimed alternative, but an alternative claim construction.” If a granted claim allows for several technically meaningful interpretations, it must be ensured that according to neither interpretation the protection conferred is extended. Because the granted claim had a technically meaningful construction requiring the presence message to indicate headset use, removing that mandatory requirement extended the protection conferred. The remaining auxiliary requests 1 to 5 also failed under Article 123(2) EPC, the added-subject-matter objection applying equally.
Analysis and implications
The decision illustrates that reliance on the description after G 1/24 does not allow a Board to disregard technically meaningful claim language. Where claim wording supports more than one technically meaningful interpretation, neither of these interpretations may extend beyond the content of the application as filed (Article 123(2) EPC) or extend the scope of protection (Article 123(3) EPC). Citing T 405/24, the Board expressly rejected an approach under which a claim is simply construed in a way that preserves validity, noting that nothing in Article 69(1) EPC or G 1/24 mandates an interpretation that necessarily complies with the EPC. The Board added that while a rule to interpret a legal document in a manner compliant with the law may find justification in contract law, a patent must be interpreted first and foremost according to the technical information it provides.
The reasoning also underlines the risk of clarifying amendments introduced during prosecution. A feature added during examination intended to express “regardless of headset use” was capable of being read as requiring the message to include specific headset-use information. Once this specific, narrower technical limitation was found not to be originally disclosed, attempts to remove it after grant broadened the scope of the claim under that interpretation, leading to an inescapable trap under Articles 123(2) and (3) EPC.
For opposition and appeal practice, T 0837/24 confirms that inconsistent reasoning in a first-instance decision can significantly affect the procedural framework on appeal. On these facts, the lack of clarity contributed to the “circumstances of the appeal case” justifying the admission of the opponent’s objection, while the self-contradiction specifically constituted “exceptional circumstances” under Article 13(2) RPBA justifying the admission of the proprietor’s late-filed auxiliary requests M-A and M-B. This procedural leeway did not, however, overcome the substantive inescapable trap. The patent was revoked.
