UPC Weekly brings you timely, thoughtful and joined-up insight into the evolving landscape of patent litigation at the Unified Patent Court.
2026 Week 35
What happens when you have different claim amendments in UPC proceedings and an EPO opposition against the same patent? It sounds like a basic question to which there must be an easy answer. But no, this one’s still being worked through.
The trite answer would be to make sure that the claims are the same in the two venues. But in Barco v. Yealink (UPC LD Brussels, 17 August 2026), an attempt to do just that was rejected by the UPC as being too late.
Background
EP 3732827 B1 was granted in June 2024 and opposed at the EPO by Yealink and others in February 2025. Opposition proceedings were accelerated and oral proceedings were held in June 2026.
In August 2025, Barco sued Yealink at the UPC for infringement of the patent, asserting claims 1, 6, 11, 12 and 13 only. In March 2026, Yealink counterclaimed for revocation of those same claims, and Barco responded with a conditional application to amend the patent, filing five auxiliary requests (AR1-AR5), which introduced features of e.g. claim 6 into claim 1 and/or various features from the description.
Back at the EPO, the opposition division (OD) found granted claim 1 to lack an inventive step. After finding claim 1 invalid, the OD allowed Barco to enter a new auxiliary request, during the oral proceedings, that combined claim 1 with granted claims 8 and 9. You’ll note that this is not a claim combination that Barco had been relying on for infringement at the UPC and so was also not a target of Yealink's counterclaim for revocation.
The OD's provisional view was that this new auxiliary request overcame the clarity issues affecting the earlier ARs and appeared to be novel, sufficiently disclosed and free of added matter. However, inventive step was left open for a further EPO hearing scheduled for 5 November 2026.
In the meantime, the interim conference at the UPC is scheduled for 8 September 2026 and the oral hearing for 3 November 2026 – two days before the second EPO OD oral proceedings.
The application to amend, again
On 4 August 2026, Barco applied to introduce a new auxiliary request – AR6 – into the UPC proceedings under Rules 30.2 and 263 RoP. AR6 has the same scope as the claims allowed into the opposition proceedings by the EPO OD – i.e., incorporating granted claims 8 and 9 into claim 1.
Barco’s reasoning was straightforward: it was reasonable to assume that the claims of AR6 could be found valid in the EPO opposition. If AR6 was not admitted into the UPC proceedings, then the claims as maintained by the EPO would differ from the claims being litigated at the UPC. Barco presented their request as contributing to a comprehensive and efficient resolution of the dispute. Barco also explained that they could not reasonably have filed the new auxiliary request any earlier.
Yealink pointed out that there was no explanation for why claims 8 and 9 had not been asserted in the original pleading, argued that “no reasonable diligence” had been made in the timing of the application, invoked an unreasonable hindrance to its defence and alleged no connection between AR6 and the arguments in their counterclaim for revocation, and no adequate case on infringement of the amended claim.
Why the UPC refused to allow AR6 into proceedings
The Court dismissed Barco’s application on two independent grounds.
Firstly, Rule 263 RoP was not satisfied. Barco had not explained why AR6 was not in its original pleading, and the Court held that admitting it now would let Barco assert the substance of granted claims 8 and 9 – never previously invoked – deep into the proceedings. The Court was not persuaded that the OD's oral hearing was really the moment this became foreseeable. Since granted claims are not open to clarity objections in EPO opposition, it should have been apparent to Barco all along that a request built from these granted dependent claims would sidestep the clarity problems dogging its other auxiliary requests.
The seven weeks between the EPO hearing (17 June) and filing AR6 at the UPC (4 August) also counted against Barco. The Court was unconvinced by Barco’s argument that it was awaiting the EPO hearing minutes, noting that Yealink's own submissions had already set out the relevant EPO findings well before Barco eventually acted.
Secondly, the Court held that AR6 was not admissible as a defence to the revocation counterclaim under Rule 30 RoP at all because Yealink's counterclaim only attacked claims 1, 6, 11, 12 and 13. Claims 8 and 9 were simply outside the scope of the UPC proceedings. The Brussels LD held that Barco could not introduce amendments in response to an attack that has not been made.
It’s messy – what’s the solution?
We have seen several other cases where claim amendments have been allowed into a UPC case on the basis that this aligns with parallel EPO opposition proceedings. It is common sense that it is preferable to avoid divergent claim amendments that affect the same patent, at least for the UPC territory.
What counted against Barco here was the fact that they limited their UPC infringement case to certain claims and did not act early enough to align auxiliary requests across the EPO and UPC tracks at the earliest opportunity.
The Brussels LD pointedly noted that Barco had not abided by the principles of procedural efficiency and so could not then use these principles to support a late change of case.
However, the fact that Barco only asserted some of the claims of the patent, and Yealink limited the revocation action to the same claims, does leave a ray of light for Barco provided that the EPO maintains the patent in amended form. Because only some of the claims have been attacked at the UPC, the UPC will not revoke the entire patent. The Brussels LD made it clear that in their view, Barco would be allowed to bring fresh UPC infringement proceedings based on the claims not yet asserted.
To avoid such additional expense and effort, for patentees running EPO opposition and UPC proceedings side by side, the message is clear: alignment is needed from the beginning and throughout.
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