2025 Week 22
As we enter the third year of the UPC, we are seeing more and more parallel UPC proceedings and EPO oppositions. Although UPC decisions are not formally legally binding on the EPO, both the UPC and EPO recognise the importance of legal certainty, procedural efficiency and harmonisation across the European patent system. They acknowledge that parallel proceedings can lead to conflicting outcomes and wasted resources – for example if the EPO revokes a patent that has formed the basis of a UPC infringement action, or if the UPC and EPO maintain the same patent but in different amended forms.
It is within this context that the UPC aims to conduct first instance oral hearings within 1 year, and the UPC Rules of Procedure (RoP) explicitly give the court discretion to stay proceedings where a parallel EPO opposition is pending, although only where the EPO decision is expected imminently. On the EPO side, opposition proceedings will be accelerated if the EPO is informed of parallel infringement or revocation proceedings before the UPC or a national court of a contracting state (OJ EPO 2023, A99).
We last looked at how parallel UPC and EPO proceedings interact a year ago in UPC Weekly 2024 Week 22, so it’s time for a revisit. A year on, we now know more about what the UPC and EPO will do when there are parallel proceedings, including when the UPC will stay proceedings and when they will not. Parties can therefore start to utilise the timings of the parallel proceedings and respective decisions to their advantage as a strategic tool in their European litigation strategy.
When will the UPC stay proceedings?
The UPC RoP state that the court can stay proceedings when a parallel EPO opposition decision “may be expected to be given rapidly” (Article 33(10) UPCA and Rule 295(a) RoP). But what does “rapidly” mean?
In Astellas v. Healios, the Munich Central Division held that in order to stay proceedings “there should be a concrete expectation (i.e. a known date in time) for a decision which date should be in the near future such that it is clearly expected to be delivered before an expected decision by the UPC”. In that case, the court considered that EPO oral proceedings being scheduled for 3.5 months after the point when the UPC considered the request for a stay to not be “rapid”, and denied the request for a stay.
In Toyota Motor v. Neo Wireless, a date for EPO oral proceedings had not yet been set, and so the Paris Central Division rejected a request to stay the revocation proceedings, citing Astellas v. Healios and explaining there was no concrete expectation, and in particular no known date in time, for the EPO decision. So, if a date for EPO oral proceedings has not been set, a UPC stay will be pretty much impossible.
In Carrier v. Bitzer, discussed in UPC Weekly here, the Court of Appeal considered that a 4 month wait for EPO oral proceedings was not suitably “rapid” in the context. The fact the EPO had accelerated the opposition proceedings did not change the Court of Appeal’s view.
In Edwards v. Meril, concerning infringement of EP 3769722 B1, the question of stays of UPC infringement proceedings running in parallel with an EPO opposition was considered in more detail, both by the first instance court and by the UPC Court of Appeal – see the decisions, in order, here, here and here. The Court of Appeal made clear in their decision that the UPC RoP do not require a final decision to be expected rapidly, and a rapidly expected decision from the Opposition Division could be sufficient for a stay, even if it is likely to be appealed. On the other hand, they also emphasised that the UPC is not required to stay UPC proceedings, even if a decision is to be expected “rapidly”. The decision is at the discretion of the court, and should be based on the balance of interest of the parties and the specific circumstances of the case, including likelihood of revocation in the EPO opposition. The Court of Appeal remitted the case back to the first instance court, where it was decided that, even though the EPO oral proceedings were scheduled for only one day after the UPC oral hearing in January 2025, there should be no stay. One reason given for the refusal was that the Opposition Division generally deliver their decision orally at the end of the oral hearing such that the outcome of the opposition proceedings would still be available before the UPC Court of First Instance issued its own decision. At the EPO opposition division oral proceedings, the patent was maintained in amended form and there is now an appeal pending, with oral proceedings in the appeal scheduled for March 2026.
In the recent decision Aylo v. Dish, the Paris Central Division was faced with a late request for a stay. The EPO opposition division had issued its preliminary opinion on the patent in March 2025 with the UPC oral hearing scheduled for 3 April 2025. The patent EP 3822805 B1 was revoked by the UPC for added matter and at the same time the UPC explained that it was a bit pointless to stay the UPC proceedings at this stage, with all of the preparation for the oral hearing having been done. The EPO opposition hearing is scheduled for 4 June 2025.
So, in general, the UPC seem to be reluctant to grant stays of proceedings pending the outcome of an EPO opposition, instead prioritising procedural efficiency and balancing the interests of the parties.
However, stays are still possible. In Edwards v. Meril, an action for infringement of EP 2628464 B1, the UPC proceedings had been stayed pending the outcome of the EPO Board of Appeal decision. The infringement proceedings were launched in June 2023 and the stay was ordered in January 2024. The EPO appeal hearing took place on 3 June 2024 with the written decision issuing on 16 July 2024, maintaining the patent in amended form. The UPC proceedings are now back underway.
In the recent NJOY v. Juul decision, the UPC Court of Appeal stayed the appeal proceedings pending the outcome of the parallel opposition proceedings before the EPO Board of Appeal. Key factors at play here were the fact that both parties agreed to the stay, the appeal proceedings were at an early stage, the UPC appeal oral hearing would be expected around the time of the EPO decision, and that there were no pending infringement proceedings that might balance against a stay.
We can therefore see that there is a general reluctance at the UPC to grant a stay based on a parallel EPO opposition. But in some cases it is possible. For those cases, provided that “expected rapidly” requirement is met for the EPO decision, it is more likely that the UPC will stay its proceedings if those UPC proceedings are at an early stage.
Conflicting decisions
Having UPC cases with parallel EPO opposition proceedings increases the possibility of conflicting outcomes. The UPC Court of Appeal considered this exact point in Carrier v. Bitzer, and observed that if either the UPC or EPO revoke the patent, in whatever sequence, then the patent is revoked at least in the UPC territory. They did not however address the question of what happens if the UPC allows an amended version of the patent in one form and the EPO allows an amended version in another. In such cases, the sequence of decisions may well be important.
Using parallel proceedings as a strategic tool
With the EPO now accelerating parallel oppositions, and the UPC’s aim of providing fast decisions, parallel EPO and UPC proceedings are often very quick (by patent litigation standards). Take a look at an example timeline of such parallel proceedings in UPC Weekly 2025 Week 6.
Parallel proceedings can also provide an opportunity for parties to strengthen their case in one forum, following the outcome of another. In fact, the UPC seem to be supporting patentees in submitting corresponding claim amendments maintained in an EPO opposition, if the EPO decision is timed appropriately. Specifically, in JingAo Solar v. Chint New Energy, the patentee was able to amend the claims in the UPC proceedings in line with the claims that had been maintained at the EPO for EP 2787541 B1, even though they were formally late-filed in the UPC proceedings. The court noted that this allowed for synchronicity between the UPC and EPO proceedings.
The cases above consider the situation where the opponent at the EPO is also one of the parties in the UPC proceedings. But in Nicoventures v. Juul and NJOY, Nicoventures were trying to gain access to the pleadings and evidence in an ongoing UPC revocation action filed by NJOY against Juul for EP 3430921 B1 and two other patents. Nicoventures had filed an opposition against the patent at the EPO. The UPC Court of Appeal decided that the EPO opposition clearly gave Nicoventures the required “direct legitimate interest” in accessing the court documents for ongoing proceedings. The Court of Appeal placed restrictions on Nicoventures’ use of the documents – they would not be permitted to file them in the EPO proceedings (where they would be immediately available to all members of the public). However, they were allowed to use the same arguments and/or prior art in those EPO proceedings.
Opponents could benefit from the even tighter deadlines as a result of accelerated EPO oppositions in parallel proceedings, by applying more pressure on the patentee to quickly defend the patent in two venues. For this reason, there could be tactical advantages for an opponent to file an EPO opposition and UPC revocation action at similar times, as the UPC would be unlikely to stay the proceedings in those circumstances. On the other hand, filing a UPC revocation action after an unsuccessful EPO opposition could give an opponent a second chance of revocation. A later-filed UPC revocation action could also be useful if the opponent becomes aware of relevant prior art after the 9-month opposition period.
The relative timings of EPO oppositions and UPC actions can also impact settlement dynamics. For example, an early EPO decision could shift leverage in settlement or licensing discussions in relation to the UPC action, and the interplay between the two timelines could become a core factor in whether, when and how the dispute settles.
Where there are parallel EPO and UPC proceedings, parties should develop flexible, forum-aware strategies that take into account how the timing and outcome of one forum may influence the other. The choice of when to file, whether to request a stay, and how to align arguments or amendments across proceedings can all have a material impact on the trajectory—and outcome—of the case. As both the EPO and UPC continue to refine their practices and case law around parallel actions, this dual-track landscape will be a dynamic and increasingly central feature of European patent litigation strategy.
