UPC litigation trends

In summary

Revocation actions and counterclaims for revocation are gaining traction at the Unified Patent Court (UPC), comprising over 40 per cent of all filed cases. With 68 standalone revocation actions and 321 counterclaims for revocations to date, both mechanisms are strategically used. Compared to EPO and national proceedings, the UPC offers faster timelines but demands strict procedural discipline and careful advance planning. Proceedings are extremely front-loaded, requiring early, comprehensive submissions and leaving little room for later adjustments. Forum choice, procedural constraints, and differing invalidation rates highlight the importance of tailored strategies in high-stakes patent litigation.

Discussion points

• Statistics for revocation cases
• Procedure and timeline of revocation proceedings
• Comparison to EPO opposition proceedings
• Comparison to national nullity proceedings in Germany

Referenced in this article

• Edwards Lifesciences v Meril (ORD_69128/2024 of 4 April 2025)
• Meril v Edwards Lifesciences (ORD_598365/2023 of 19 July 2024)
• NanoString Technologies v 10x Genomics decision (UPC CoA 335/2023 of 26 February 2024)
• Juul v NJOY (UPC CoA 237/2025 of 28 April 2025)
• Kunststoff KG Nehl & Co v Häfele SE & Co. KG (ORD_18972/2025 of 18 April 2024)
• NJOY Netherlands v Juul Labs International (ORD_598564/2023 of 17 January 2025)

Revocation actions and counterclaims at the UPC: a growing pillar of patent strategy

The UPC continues to see steady growth in litigation activity, with 946 cases filed before the first instance by the end of June 2025. Among these, challenges to patent validity – either through central revocation actions or counterclaims in infringement proceedings – constitute a substantial and strategically significant portion.

Key figures

• 68 standalone revocation actions (filed directly with the Central Division)
• 321 counterclaims for revocation (filed as defensive actions during infringement proceedings)
• 351 infringement actions

Combined, revocation actions and counterclaims for revocation comprise over 40 per cent of the totality of UPC cases filed to date, underscoring their strategic importance.

Central versus local dynamics

The procedural framework of the UPC offers two principal paths to challenge a patent’s validity: a standalone revocation action filed at the Central Division, and a counterclaim for revocation brought within the context of an infringement suit before a Local or Regional Division. Both mechanisms are being actively used, but with distinct strategic aims and geographical concentrations.

The majority of standalone revocation actions – currently totalling 68 – have been filed with the Central Division, predominantly in Paris, followed by Munich and Milan. Litigants using this route typically aim to pre-empt infringement litigation by attacking the patent’s validity head-on, often in industries like pharmaceuticals, medical devices and consumer electronics.

In contrast, counterclaims for revocation – 321 to date – are lodged in the context of infringement proceedings brought before Local Divisions, particularly in Germany. The Munich and Düsseldorf divisions, with their strong reputations and experienced patent judges, have attracted a large share of these cases. Here, counterclaims for revocation are frequently used as a defensive tool for accused infringers, embedded within a broader litigation strategy that may also include contesting jurisdiction, seeking stays or requesting bifurcation. These differing procedural contexts shape the nature and timing of validity assessments at the UPC and are giving rise to increasingly complex litigation dynamics.

The patentee-friendly tilt

Although many had anticipated that the UPC might provide a more revocation attack-friendly forum – particularly through its Central Division’s UPC territory-wide revocation power – the court's early decisions suggest a more balanced or even patentee-favourable tendency.

Based on reported decisions to date, approximately 60–65 per cent of standalone revocation actions before the Central Division have resulted in patents being upheld, either in full or in amended form. In contrast, only 35–40 per cent of these actions have led to full revocations. For counterclaims for revocation – raised defensively during infringement proceedings in Local or Regional Divisions – the success rate is lower, with available data pointing to invalidation in no more than 30 per cent of decided cases.

However, it is still early days. With only a limited number of revocation decisions published to date, these figures may shift as more complex and high-value patents come under scrutiny.

Rising complexity of litigation strategies

The structure of the UPC enables more complex scenarios. While defendants in infringement proceedings may attack patents by a counterclaim for revocation before the competent Local Division, the same patent may be challenged by other parties in central revocation actions before the competent Central Division. Such parallel proceedings put pressure on the patent owner to defend the same patent in multiple fora and potentially accelerates an invalidity decision if the Central Division moves faster than the Local Division.

Procedure and timelines: counterclaims and standalone revocation actions at the UPC

Procedural efficiency is one of the core promises of the UPC. Whether pursued as standalone revocation actions or as counterclaims in infringement proceedings, the legal framework at the UPC imposes clear and compressed timelines.

Standalone revocation actions in the main proceedings

A standalone revocation action is filed directly with the Central Division of the UPC. It can be initiated at any time against any unitary patent or any European patent for which no opt-out has been filed. It is particularly attractive for generic companies or potential infringers seeking to ‘clear the way’ before launching a product.

Proceedings before the UPC Court of First Instance are structured into three main stages: a written procedure, an interim procedure and an oral hearing. In standalone revocation actions, initiated directly before the Central Division, the plaintiff files the revocation action, which is served on the patentee, who must respond within two months – possibly including an application to amend the patent (usually in form of auxiliary requests). The written stage continues with optional reply and rejoinder rounds (typically two months and one month, respectively), including further exchanges on auxiliary requests if filed.

This is followed by the interim procedure, usually concluded within three months. A key part of this phase is the interim hearing with the judge rapporteur, where procedural and substantive matters are clarified, deadlines are fixed and the structure of the final oral hearing is discussed.

The oral hearing itself – usually held in person unless otherwise agreed – is typically scheduled 12 to 14 months after filing the action. While procedural rules allow for flexibility, the hearing is usually completed in a single day and can involve next to oral arguments also technical expert testimony. Usually, the oral pleadings and resulting discussion are focused of the most relevant prior art or claim amendments. Whether the court issues a preliminary opinion at the start of the hearing depends on the forum chosen (German local divisions and the Central Division in Munich usually do so). After the hearing, the court aims to issue a reasoned written decision within six weeks.

Counterclaims for revocation in the main proceedings

A counterclaim for revocation is a legal instrument available to defendants in UPC infringement proceedings and must be filed together with the statement of defence. It provides a procedural route to challenge the validity of the asserted patent within the same court proceedings, avoiding the need for separate revocation proceedings before the Central Division.

The counterclaim is submitted as part of the defence, which is due within three months of service of the infringement action. The written procedure continues with optional reply and rejoinder rounds: the plaintiff (patentee) may respond with a reply within two months, and the defendant may follow with a rejoinder within one month (in cases without counterclaim for revocation) or two months (in cases with a counterclaim for revocation).

PI proceedings

Decisions on provisional measures (PI proceedings) before the UPC are typically issued within three to four months, significantly faster than the main proceedings. To obtain a PI, the applicant must demonstrate entitlement, validity and infringement, with the burden of proof for invalidity lying more on the defendant in inter partes cases. The requirements of urgency and balance of interests must be proven more rigorously. The court examines whether the applicant acted swiftly and without undue delay, though interpretations of urgency vary between divisions. If a PI is granted, the applicant must file the main infringement action within 31 calendar days or 20 working days, or risk revocation of the PI at the defendant’s request.

Strategic observations

The procedural windows in UPC revocation actions are tight – especially compared to national nullity actions before national courts or EPO oppositions. Both revocation paths (standalone and counterclaim) are front-loaded, with early deadlines for amendment requests, backed by strict preclusion rules if, for example, auxiliary requests are not timely submitted.

Time extensions under the UPC are generally granted only in exceptional circumstances. Parties must submit a reasoned request justifying the need for additional time, and such requests are scrutinised carefully by the court. The UPC’s procedural culture emphasises expediency and discipline, meaning that extensions disrupt the structured timeline only where truly necessary. In practice, the bar for obtaining an extension is high, and litigants are advised to plan filings with strict procedural adherence in mind.

UPC revocation actions and EPO opposition proceedings

Unlike in the German national patent system, where a nullity action is inadmissible during the opposition period, it is possible to file a revocation action before the UPC – either standalone or as a counterclaim – while opposition proceedings may still be pending or even initiated at the EPO. This is true even if both the revocation action and the opposition are filed by the same party and allows challengers to choose between the two options, or go with both in parallel. Of course, the prerequisite is that the opposition period of nine months after the grant of the patent has not yet expired.

Advantages of EPO opposition proceedings

A first advantage of filing an opposition before the EPO is the larger territorial scope of the potential revocation decision. While a UPC revocation only has effect for the 18 member states participating in the unitary patent system, an EPO opposition extends to all 39 EPC member states, notably including countries like the United Kingdom and Switzerland, plus – if applicable – extension and validation states. Further, the total expenses for EPO opposition proceedings in average complexity cases typically still attain five-digit amounts in euro, whereas a UPC revocation action can easily cost up to the five-fold amount or even more. It must be noted though that in UPC proceedings, a substantial proportion of costs can generally be recovered and claimed from the losing party, which is not the case before the EPO.

Advantages of UPC revocation actions

On the upside for the UPC, the streamlined proceedings lead to a faster decision compared to an EPO opposition. The UPC’s first instance decision on the revocation action is generally issued around one year after its filing. In contrast, an EPO opposition takes approximately two years from filing the notice of opposition until oral proceedings. If the case goes up to the second instance, the numbers mentioned roughly double – ie, the UPC appeal stage takes approximately another year, while the appeal at the EPO typically takes another two years.

As an aspect of material law, the EPO strictly applies its well-known problem-solution-approach (PSA) for assessing inventive step. Conversely, the exact approach of the UPC is not fully settled yet. There have been first-instance decisions sticking to the PSA (Edwards Lifesciences v Meril, ORD_69128/2024 of 4 April 2025), and others supporting a less formal approach (Meril v Edwards Lifesciences, ORD_598365/2023 of 19 July 2024). The UPC Court of Appeal emphasised in its NanoString Technologies v 10x Genomics decision (UPC CoA 335/2023 of 26 February 2024) that there is no need to identify ‘the closest prior art’. At present, it therefore appears that the UPC may not apply the PSA as strictly as the EPO. This generally raises the bar for patent validity compared to EPO practice, and is an important factor for strategic considerations.

Case-specific aspects

There are further differences between UPC revocation actions and EPO opposition proceedings, which may be an advantage or disadvantage depending on the circumstances of the case. For example, the opposition divisions of the EPO usually consist of technical members, whereas the UPC panels have more legally qualified judges than technically qualified judges. Depending on the technical depth of the case, this may be a reason to choose either the EPO or the UPC or both in parallel. As a further example, oral proceedings before the EPO are more fragmented with individual aspects of the case being pleaded and decided separately, while oral proceedings at the UPC involve long, comprehensive pleadings of the parties with less questions and one final decision at the end. Finally, first-instance oral proceedings at the EPO are generally held as a video conference, which may be beneficial in cases where cost-effectiveness is important, but less desirable for high stakes cases.

EPO opposition and UPC revocation in parallel

The more important the outcome of a patent dispute is, the more advisable it is to file both a notice of opposition at the EPO and a revocation action at the UPC. While this is more costly of course, the party aiming for a revocation of the patent has a second shot to convince a different panel in case it does not succeed at the first. A specific aspect that has to be taken into account in such cases is the stay of the UPC proceedings. However, if the same party files both the notice of opposition and the revocation action approximately at the same time, the faster proceedings at the UPC usually lead to an earlier decision, which leads to the requirements for a stay not being met. This applies even though the EPO has enacted provisions to accelerate opposition proceedings in the case of parallel UPC actions (cf. OJ EPO 2023, A99). Nevertheless, parallel proceedings may also occur because another party has already filed an opposition in advance. If in such cases a decision of the EPO is expected rapidly, the UPC may generally stay its proceedings. In Juul v NJOY (UPC CoA 237/2025 of 28 April 2025) for example, where a final decision of the EPO Boards of Appeal could be expected only some days before or after the possible date for an oral hearing before the UPC court of appeal, the latter had stayed proceedings based on an agreement of the parties. Still, the hurdles for a stay are rather high.

UPC revocation actions v national nullity proceedings in Germany

Traditionally, many patent disputes in Europe have been litigated and decided in Germany, owing to its extremely cost-efficient, high quality and rather patentee-friendly litigation venue. Since the UPC’s launch, patent owners and challengers in Germany operate within a fundamentally transformed validity landscape.

Jurisdictional framework: when choice exists

For unitary patents, the UPC holds exclusive jurisdiction. The real strategic options arise with bundle patents (European patents validated in each national country of interest as in the past), where the current transitional period running until 2030 creates a complex jurisdictional landscape. During this period, both UPC and national courts may have competence for validity challenges unless an opt-out has been filed or the 'first-seized' principle applies: once proceedings concerning a specific patent are initiated before either forum (UPC or national), that forum gains exclusive jurisdiction for subsequent revocation actions.

This framework entails strategic considerations for both sides. Patent owners must consider forum choice when filing infringement actions, as this determines where they will likely face subsequent revocation challenges. Patent challengers must assess both strategic merits and legal availability of each forum before initiating proceedings.

Procedural architecture: dual-track UPC v single national proceeding

While the German Federal Patent Court offers a single standalone nullity proceeding (a hallmark of Germany’s bifurcated patent litigation system), the UPC presents two distinct pathways for validity challenges: standalone revocation actions before the Central Division and counterclaims for revocation within infringement proceedings before Local Divisions.

Patent owners filing infringement complaints at the UPC may face validity challenges across multiple fora. Beyond expected counterclaims for revocation, they may simultaneously face standalone central revocation actions from other parties. This dual-track system introduces strategic complexity that is absent if the German national route is chosen. In the latter case, additional complexity may of course arise if multiple national litigation proceedings are initiated in different countries.

Timelines

At the German Federal Patent Court, nullity proceedings follow a familiar pattern: after filing a nullity action, the patent proprietor has two to three months to respond. Ideally, the Federal Patent Court issues qualified preliminary opinion six months after service of the nullity action, even though we see a large variance in when the qualified preliminary opinion are in practice issued. While these early assessments provide valuable early guidance to parties, the duration of proceedings is rather long compared to the UPC. Despite the Federal Patent Court streamlining its operations significantly compared to the average case duration from 32.8 months in 2020, the duration of nullity proceedings was still around 21 months in 2023.

In contrast, UPC revocation proceedings operate under compressed timelines that prioritise speed. Short time limits for filing writs are set, late-filed pleadings can be disregarded and a qualified preliminary opinion is not foreseen. In terms of duration of proceedings, this strict schedule pays off. Standalone central revocation actions average around 12–14 months from filing to decision.

Amendment strategies: auxiliary requests under different regimes

In German nullity proceedings, patent owners traditionally defend their patents not only in its granted form, but also in a variety of amended forms. The Federal Patent Court has traditionally allowed patent owners considerable latitude in presenting alternative claim sets.

The UPC agreement has introduced the requirement that auxiliary requests be 'reasonable' in number, depending on the circumstances of the case. In the early landmark decision in Meril v Edwards Lifesciences (ORD_598365/2023 of 19 July 2024), the Central Division Paris considered 84 auxiliary requests based on nine conditional amendments to be 'extremely high, potentially hindering the efficiency of the UPC proceedings', yet ultimately deemed them not 'unreasonable'. However, other decisions suggest a considerably lower limit around 10 or 12 auxiliary requests (Kunststoff KG Nehl & Co v Häfele SE & Co KG, ORD_18972/2025 of 18 April 2024; NJOY Netherlands v Juul Labs International, ORD_598564/2023 of 17 January 2025).

Thus, unlike the Federal Patent Court’s more permissive approach, UPC patent owners must balance comprehensive defence strategies against the risk of having auxiliary requests rejected.

Substantive law: the UPC’s search for its path on inventive step

The UPC has not yet settled on a uniform way to assess inventive step. While the Federal Patent Court consistently applies the traditional German approach, the UPC is still caught between the EPO's structured problem-solution approach which provides predictable but sometimes technically artificial results and more intuitive but less predictable German approach. While in many cases, both approaches lead to similar results, this may not be true for each individual case – a fact that needs to be considered when choosing a forum.

Invalidation rates

The invalidation rate at the Federal Patent Court measuring complete patent revocation has consistently ranged between 35 per cent and 45 per cent over the past two decades, differing, however, by technical subject matter. Early UPC data suggests similar overall invalidation rates, although with notable variations between divisions. However, this comparison must be approached cautiously given the UPC's nascent stage. Selection bias may influence early statistics, as patent owners might have strategically chosen to enforce only their strongest patents at the UPC initially or conversely, challengers may have targeted particularly vulnerable patents for early test cases.

Strategic implications

The availability of central revocation actions and counterclaims for revocation before the UPC has opened up new strategic options both for patent owners and challengers. Key considerations for the decision where to assert or challenge a patent include forum availability (opt-out status, first-seized principle) and potential difference in inventive step methodology. The UPC's speed in validity decisions (14 months average) comes at the price of strict deadlines and decreased flexibility, while the Federal Patent Court offers more procedural flexibility but longer timelines (21 months). Invalidation rates (35–45 per cent) are comparable and do not allow universal recommendations for patent owners or challengers.

Outlook

As the UPC matures, revocation actions and counterclaims are expected to remain central tools in patent litigation. With increasing case volume and evolving procedural practice, parties will need to adapt to the court’s front-loaded and fast-paced approach. While more case law will bring clarity, early strategic planning and procedural precision will continue to be critical for success. The growing caseload also suggests that the UPC is gaining traction as a preferred venue for pan-European patent disputes.

This article was first published on IAM in September 2025; for further in-depth analysis, please visit the IAM - Europe, Middle East and Africa Patent Prosecution Review 2026

Picture credits: Jarama_AdobeStock.com