CoA: No Extension by Auxiliary Request

Barco v Yealink – Court of Appeal, order of 16 October 2026, UPC-CoA-145/2026

Can a patent proprietor introduce a new auxiliary request into UPC proceedings after that request has been admitted in parallel EPO opposition proceedings? And can such a request be used to rely on claims that were not originally asserted in the infringement action?

The Court of Appeal has confirmed the Brussels Local Division's refusal to admit an additional auxiliary request. In the circumstances of the case, the request was not aimed at defending the patent against revocation but rather at extending the infringement action to previously unasserted claims. The Court also found that the proprietor had failed to justify the late submission.

The dispute

Barco brought an infringement action against Yealink before the Brussels Local Division, relying on claims 1, 6, 11, 12 and 13 of EP 3 732 827. Yealink filed a counterclaim for revocation directed against those claims.

Barco defended the patent as granted and filed five auxiliary requests.

In parallel, opposition proceedings were pending before the EPO. Interestingly, Barco had filed no fewer than 267 auxiliary requests in those proceedings.

During the EPO oral proceedings in June 2026, Barco introduced even further auxiliary requests. One of these, combining granted claims 1, 8 and 9, was admitted by the Opposition Division. The Opposition Division found no objections concerning added matter, sufficiency or novelty. Inventive step remained to be discussed at a further oral proceeding.

Barco subsequently sought to introduce the same claim combination into the UPC proceedings as a sixth auxiliary request (AR6).

The Brussels Local Division refused permission. Barco appealed.

An auxiliary request aimed at extending the infringement action

The Court of Appeal upheld the refusal.

The decisive point was that claims 8 and 9 had neither been asserted in the infringement action nor challenged in the counterclaim for revocation.

AR6 essentially corresponded to granted claim 9. Since that claim was not under attack, it would survive the counterclaim for revocation irrespective of whether AR6 was admitted.

The Court therefore considered that the proposed amendment was not aimed at defending the patent against revocation. Rather, it appeared intended to extend the infringement action to subject-matter that Barco had not originally invoked.

The Court held that R. 30.2 RoP could not be used for that purpose.

The fact that AR6 formally amended claim 1, which was challenged in the counterclaim, did not change this assessment.

Late amendments require justification

The Court of Appeal also confirmed the refusal on procedural grounds.

Under R. 30.2 and R. 263 RoP, subsequent amendments may be admitted only with the Court's permission. The Court must consider, in particular, whether the amendment could have been made earlier with reasonable diligence and whether its admission would unreasonably hinder the opposing party.

Barco had not explained why claims 8 and 9 were omitted from the original infringement action or why the corresponding amendment had not been included among its initial UPC auxiliary requests.

The fact that AR6 had been introduced during the EPO oral proceedings did not justify its late submission at the UPC. The relevant claim combination could have been submitted earlier. Moreover, Barco waited more than seven weeks after the EPO hearing before requesting its admission.

Admitting AR6 would also have required Yealink to address additional infringement and validity issues shortly before the scheduled UPC oral hearing.

The Court of Appeal therefore found no error in the Local Division's exercise of discretion.

Parallel EPO proceedings require careful coordination

Barco also relied on the differences between EPO and UPC procedures concerning auxiliary requests.

The Court of Appeal took the opposite view.

It acknowledged that the two systems have different procedural rules. However, these differences make it all the more important for a patent proprietor to coordinate its position carefully in parallel EPO and UPC proceedings.

The proprietor cannot rely on developments in EPO opposition proceedings to justify an amendment that could have been introduced earlier at the UPC.

Takeaways

• An auxiliary request may be refused where it effectively seeks to extend the infringement action to claims that were neither originally asserted nor challenged in the counterclaim for revocation.
• Ever wondered why you should assert dependent claims in an UPC infringement action from the outset, at least by way of an “in particular” request? This is why.
• Subsequent auxiliary requests under R. 30.2 RoP are subject to the same principles as amendments under R. 263 RoP, including reasonable diligence and the absence of unreasonable prejudice to the opposing party.
• Developments in parallel EPO opposition proceedings do not automatically justify late amendments at the UPC. The different procedural rules require careful coordination from the outset.

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