The UPC After Three Years: From Experiment to Enforcement Forum

The Unified Patent Court opened on 1 June 2023 against a backdrop of considerable uncertainty. While some users welcomed the prospect of a new forum offering pan-European relief, others adopted a more cautious “wait and see” approach. Now that the Court has completed its first three years of operation, its filing trends provide a useful indication of how the system is being used in practice.

Filing Numbers

The UPC marked the third anniversary of its opening on 1 June 2026. Over its first three years, a total of 1,282 cases were filed at the UPC Court of First Instance, the number having passed the 1,000 mark during 2025. This included 582 infringement actions, 98 “standalone” revocation actions, and 164 applications for provisional measures. These categories represent the main types of original actions and applications. Other types, such as counterclaims for revocation and infringement, or applications for cost decisions, are generally subsidiary to one of these three main types of action and make up the balance of the 1,282 cases. By focusing on these “original” actions, we can get a picture of UPC users’ activities and confidence in the system.

The early period: a strong start in 2023

By December 2023—little more than six months after opening—the UPC had already attracted a meaningful number of cases, including 67 infringement actions, 24 revocations, and 13 applications for provisional measures. Some of this early activity is likely to have reflected a stock of cases that had effectively been held back and prepared in anticipation of the court opening, so that they could be filed once the UPC became available. Even allowing for that initial flurry, however, the figures are striking. Early uptake showed that a significant number of litigants were prepared to commit to the new system from the outset, rather than waiting for a longer bedding-in period or a substantial body of case law.

Consolidation during 2024

Throughout 2024, filing numbers continued to rise at a broadly consistent pace. By the end of December 2024, cumulative filings had increased to 231 infringement actions, 56 revocation actions, and 62 provisional measures applications.

Acceleration in 2025

The most striking feature in the dataset is the acceleration observed during 2025, particularly in the second half of the year. By the end of June 2025, cumulative filings stood at 342 infringement actions, 68 revocations, and 94 provisional measures applications. By year-end, those numbers had jumped to 497, 88, and 135 respectively. By the end of 2025, more than half of all infringement actions that had been filed with the UPC were filed in 2025 itself, with a substantial proportion concentrated in the second half of the year. Applications for provisional measures showed a similar pattern of acceleration.

While the dataset does not explain the causes, several factors are likely to have contributed: increasing familiarity with UPC procedure, a growing body of decisions and orders to guide litigants, and greater confidence in timelines and remedies. Whatever the precise mix of drivers, the data points to a system that was gathering momentum rather than plateauing.

The third year: momentum sustained into 2026

The court’s third year confirmed that the acceleration seen during 2025 was not an aberration. In the first five months of 2026, a further 224 cases were filed at the Court of First Instance, including 85 infringement actions, 10 standalone revocation actions, and 29 applications for provisional measures. At around 45 new cases per month, filings have continued at the elevated pace established in late 2025, albeit below the exceptional peak reached in November and December of that year.

Comparing the court’s three years side by side makes the trajectory clear. Infringement filings rose from 126 in the first year (June 2023 to May 2024) to 186 in the second, and then to 270 in the third—meaning that almost half of all infringement actions ever filed at the UPC arrived in its third year alone. Applications for provisional measures followed a similar path, rising from 32 to 56 and then to 76 across the same three periods.

Shifts in the case type mix

Looking not just at absolute numbers but at proportions over time reveals a gradual shift in the case-type mix. In late 2023, infringement actions accounted for around 64% of filings, with revocations around 23%. By the end of 2025, infringement actions had risen to nearly 70%, while revocations had fallen to around 12% of the total. That mix has since stabilised. At the three-year mark, infringement actions accounted for around 70% of the three main categories, with revocations at around 11%.

This does not mean that revocation actions became less common in absolute terms—the cumulative total has continued to rise—but rather that enforcement activity grew far more quickly. The UPC’s role appears to be evolving into that of a mainstream enforcement forum, rather than being used primarily as a central revocation alternative to national proceedings.

Not the patent graveyard some feared

The widening gap between infringement and revocation filings deserves particular attention, because it speaks directly to one of the great anxieties that preceded the court’s opening. A central objection to the UPC, and a principal reason so many proprietors opted their European patents out of the system, was the fear that it would become a pan-European revocation machine: a single forum in which a competitor could knock out a patent across the whole of the participating territory in one action. Three years of filing data suggests that this feared outcome simply has not materialised.

At the end of 2023, infringement actions outnumbered standalone revocation actions by a little under three to one. By the end of the court’s third year, the ratio had widened to a little under six to one on a cumulative basis, and the trend among new filings is starker still. In the third year alone, 270 infringement actions were filed against just 33 standalone revocations—more than eight to one. Indeed, while annual infringement filings have more than doubled since the court’s first year, the number of new revocation actions was significantly lower in years two and three, at 25 and 33 respectively, than in the first year, in which 40 revocation actions were filed.

The headline number of standalone revocation actions also likely overstates the amount of genuinely pre-emptive central validity litigation. Some actions recorded as standalone revocation actions are, in practical terms, responses to actual or threatened assertions, including applications for provisional measures. The true number of revocation actions brought simply to clear the way, without a live enforcement context, is therefore likely to be lower than the raw figures suggest.

The comparison with EPO oppositions puts this in perspective. Across the period from June 2023 to the end of May 2026, roughly 7,000 European patents were opposed, corresponding to an opposition rate of about 2.2% of granted European patents.

By contrast, the 98 standalone revocation actions filed at the UPC over the same June 2023 to May 2026 period correspond to a revocation-action rate of only around 0.05% of non-opted-out European patents granted in that period. That figure is, if anything, a generous upper limit. Unlike an EPO opposition, a UPC revocation action is not confined to a nine-month post-grant window, so the pool of patents theoretically exposed to UPC revocation is broader than the cohort of recently granted, non-opted-out patents used for the comparison.

There are good reasons why the patent graveyard failed to materialise. For those seeking to clear a patent centrally, opposition at the European Patent Office remains available for nine months after grant, is considerably cheaper than a UPC revocation action, and takes effect across all EPC states rather than only the UPC territory. Meanwhile, validity challenges at the UPC arise overwhelmingly in a defensive posture, as counterclaims within infringement proceedings, rather than as pre-emptive strikes. The picture that emerges is of a court whose centre of gravity lies firmly in enforcement, with revocation playing a largely responsive, subsidiary role—almost the inverse of what the system’s early sceptics predicted.

Interim relief as a core feature

One consistent theme throughout the period is the prominence of applications for provisional measures. With 164 applications by the end of May 2026, interim relief is clearly not a marginal feature of UPC litigation. Instead, it forms a significant part of the court’s procedural landscape, reinforcing the perception that parties are prepared to use the UPC for both urgent and final relief.

Looking ahead

Three years in, the UPC has moved well beyond its launch phase. The filing data shows sustained growth and a clear acceleration, with infringement actions firmly at the centre of the court’s workload. The opening of the court’s Patent Mediation and Arbitration Centre in May 2026 adds a further dimension, offering parties a route from litigation into mediation or arbitration without abandoning proceedings already under way. While longer-term trends will depend on future decisions, remedies, and market behaviour, the first three years suggest that the UPC has established itself as a serious and increasingly popular forum for European patent litigation.

Language

Despite a strong start for German as the most common language of proceedings at the UPC, the data shows a clear and rapid shift, with English overtaking German as the most frequently used language for first-instance proceedings filed in 2024.

The direction of travel is consistent. English moves from a minority position to a clear majority, and retains that lead across subsequent snapshots. In 2024, the ratio of cases filed in English to those filed in German was about 1.6 to 1. That gap has continued to widen. In the first five months of 2026, English accounted for around 69% of new cases at the Court of First Instance against 26% for German—a ratio of around 2.6 to 1.

Several factors likely explain this development.

The growing use of the UPC for enforcement favours English

As infringement actions increasingly dominate the court’s workload, claimants—particularly those seeking pan-European relief—may default to English as the most commercially neutral and widely understood litigation language. For many international disputes, English is already the working language between parties, even where neither is based in an English-speaking jurisdiction.

The internationalisation of UPC litigation

As more non-European and cross-border European litigants engage with the UPC, English naturally becomes the lowest-friction choice. This is especially true where legal teams, in-house counsel, and technical experts are already accustomed to operating in English in other international forums, reducing translation costs and complexity.

Early strategic caution favoured German Local Divisions

It was only in the days before the court started operating that the German local divisions decided to hear cases in English, which led many of those preparing their cases in advance to do so in German. As confidence in the UPC has grown—and as procedure and case law have become more predictable—that initial home-court effect appears to be weakening, with users prioritising broader accessibility over national familiarity, at least when it comes to language.

German-language capacity may become a bottleneck

A further, more institutional reason may also point in the same direction. UPC local-division panels are multinational. In the German local divisions, the panel includes two German legally qualified judges and one legally qualified judge from another Contracting Member State. If a case is conducted in German, that non-German judge must also be able to work effectively in German. As the German local divisions continue to attract a high share of the court’s workload, heavy use of German as the language of proceedings could therefore create a capacity constraint, because the pool of non-German judges able to sit comfortably in German is necessarily more limited than the pool able to sit in English.

That practical constraint gives users and the court a shared reason to favour English in appropriate cases. For litigants, English may reduce the risk of delay or allocation friction in a busy system. For the court, greater use of English may make it easier to draw flexibly on the multinational judicial pool and avoid concentrating pressure on the comparatively small group of non-German judges who can hear German-language cases.

Institutional momentum

Now that English dominates filings, it becomes easier for it to reinforce its own position. Pleadings, decisions, and advocacy experience accumulate in English, making it an ever more practical default for subsequent cases.

Overall, the data suggests that language choice at the UPC is increasingly being driven by the court’s role as a pan-European enforcement forum, rather than by national litigation traditions. English’s rise appears less a temporary fluctuation and more a reflection of how users now see—and use—the UPC in practice. It also highlights the advantages of well-integrated pan-European teams, like the team at EIP, which includes both native German and English speakers.

Location

One of the clearest structural features of UPC activity to date is the strong concentration of cases in German local divisions. While this dominance is striking in numerical terms—the German local divisions account for around three quarters of all cases where the claimant may have had a choice of division—it is not particularly surprising when viewed against the background of European patent litigation practice.

Institutional continuity and user familiarity

German courts have, along with the courts of England and Wales, long been Europe’s primary patent litigation venues, with Munich, Düsseldorf and Mannheim in particular handling large volumes of technically complex infringement actions for decades. With the UK’s departure from the UPC system, Germany remains the dominant national venue.

For many litigants, these divisions represent not a leap into unfamiliar territory but a continuation of established litigation habits, now operating within a UPC framework. Judges, procedural rhythms and advocacy styles in these divisions are perceived as familiar, which reduces perceived litigation risk in a new court system.

Speed, predictability and remedies

German patent courts have a reputation for efficient case handling and relatively predictable outcomes, especially in infringement proceedings. That reputation transfers naturally to the German UPC divisions, which are often seen as offering a combination of speed and technical competence. For claimants seeking rapid, pan-European enforcement, German local divisions therefore present a compelling balance between novelty (the UPC) and reliability (a familiar judicial culture).

Claimant-driven forum choice

The UPC system gives claimants an essentially free choice over forum selection when filing infringement actions in many cases. In practice, this means claimants can gravitate toward divisions perceived as more predictable or claimant-friendly. The German local divisions’ prominence in the data therefore reflects strategic claimant choice, rather than merely geographic happenstance.

What this tells us about the UPC’s early character

The focus on German local divisions underscores that, in its formative years, the UPC is being used primarily as an enforcement forum anchored in established litigation centres, rather than as a fully decentralised pan-European court. This does not diminish its European character; rather, it highlights how deeply existing litigation cultures shape the adoption of new institutions.

A self-correcting trend?

A quieter but important factor is institutional capacity. The UPC Agreement itself limits the number of local divisions in any single country to four, and the ability of the UPC to expand capacity in Germany is unclear. If the German local divisions begin to experience delays and procedural bottlenecks, claimants with the ability to choose the venue will start to look elsewhere. Even small increases in time-to-decision can materially alter enforcement strategy, particularly in fast-moving technology markets. There are early signs of exactly this dynamic in the most recent data. In the first five months of 2026, the German local divisions received around two-thirds of new infringement actions—still clearly dominant, but a step down from the roughly three-quarters share seen over the court’s first two and a half years.

Conclusion

Three years on, the central lesson from the data is that users are not merely experimenting with the UPC; they are increasingly choosing it. The steady rise in filings, the acceleration of infringement actions, and the growing use of the court for urgent relief all point to a system that litigants see as useful, credible and strategically valuable.

At the same time, many of the most serious early concerns have not materialised. The court has not become the patent graveyard some feared; standalone revocation actions remain modest in number and are often defensive in character. Nor has the system remained a niche or cautious forum used only by early adopters. Instead, it has developed into a mainstream enforcement venue, anchored in established litigation centres but increasingly international in language, users and outlook.

That is not to say that the system is fully settled. Potential capacity constraints, particularly if work remains heavily concentrated in particular divisions, and the still-developing body of first-instance and appellate case law will continue to shape how the UPC develops. But these are signs of a young court scaling up, not of a system failing to take root. Capacity pressures should ease as users diversify their choice of division and the court adapts its resources and working practices; legal uncertainty should diminish as more decisions are issued and the Court of Appeal continues to give guidance. Judged against the uncertainty that surrounded its launch, the court’s first three years have been a remarkable success. The UPC has established itself faster and more decisively than many expected.

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