The Most Active Litigants at the Unified Patent Court in 2026

A small group of repeat players drives a large share of the Unified Patent Court's docket. Of the roughly 2,800 cases our platform has classified, about 1,800 are substantive, the merits actions and their direct counterparts (infringement, revocation, provisional measures, appeals) rather than procedural sub-applications. Across those cases we track close to 1,900 distinct parties, and around a quarter of them appear only once. But a couple of dozen names, once you group each corporate family together, carry a disproportionate share of the substantive caseload. And the busiest of them all is not a patent owner. It is a defendant.

Xiaomi has been named in more substantive UPC cases than any other party, and it sits more often on the respondent side than the claimant side. The way it gets there is the first lesson in reading these rankings: a corporate group litigates through many national entities, and the number that matters aggregates the family rather than the flag.

How we count

A note on method, because it changes the picture. We count distinct substantive cases, not raw filing appearances. A single dispute can spin off an infringement action, a revocation counterclaim, and a run of procedural sub-applications; tallying each of those as a separate entry turns one fight into dozens. Excluding procedural matters and consolidating subsidiaries into corporate families gives a truer read of who is actually carrying the most litigation, and it is why the counts below are measured in tens, not hundreds.

The most active UPC litigants

The table ranks the busiest corporate groups by total substantive cases. "Claimant-side" counts the cases where the group brought or pursued the action; "respondent-side," where it answered one. Many parties sit on both sides across their portfolio, because a defendant in an infringement action routinely counterclaims for revocation, and a patentee sued for revocation defends and counter-asserts. "NPE" (non-practising entity) is a neutral label for a company that licenses and asserts patents rather than making products.

Counts are distinct substantive cases classified by our platform, grouped by corporate family. Figures move as new decisions are added.

A note on grouping. Large groups litigate through many national entities, and the public record lists each one separately. Xiaomi is the clearest example: its German, Dutch, French and other national units each appear in the docket, and only by collapsing the family into one combatant does it reach the top of the table, almost entirely on the defending side. The same caveat applies, more modestly, to Meril, Kodak and others. Read the rankings as the shape of the docket, not a precise league table.

Standard-essential patents: licensors versus implementers

The largest single pattern is the standard-essential-patent (SEP) fight between cellular-technology licensors and the smartphone makers who implement their standards. On the licensing side sit the patent owners that file more than they defend: Huawei, Ericsson, Nokia, Philips. On the other are the implementers that show up mostly as respondents: Xiaomi, OPPO, Samsung, Motorola.

The anchor case is Panasonic v. OPPO. On 22 November 2024 the Mannheim Local Division handed down the UPC's first FRAND ruling, finding that OPPO infringed Panasonic's standard-essential patent and granting an injunction across Germany, France, Italy, the Netherlands and Sweden (McDermott; A&O Shearman). Panasonic ran roughly a dozen UPC actions against OPPO and Xiaomi from a single campaign, which is how one licensor generates a block of cases. But the campaign is now over: after the English courts granted Xiaomi an interim licence that undercut the parallel proceedings, Panasonic settled its SEP disputes with both Xiaomi and OPPO in late 2025 (JUVE Patent). Panasonic's balanced count, 24 cases on the claimant side and 29 on the respondent side, is the residue of a campaign that drew as many revocation counterclaims as it filed infringement actions.

The medtech rivalries: heart valves and glucose monitors

The second pattern is operating-company rivalry in medical devices, where two firms litigate each other repeatedly across a product line.

Edwards Lifesciences v. Meril is the transcatheter-heart-valve fight. Edwards (18 claimant-side, 19 respondent-side) and Meril (26 and 17) have produced a long run of UPC actions over prosthetic heart valves and delivery systems; the Munich Local Division granted Edwards an injunction with product recall and destruction, and further rounds followed. The near-symmetry of each side's counts is the signature of a true two-front war, each company asserting its own patents while defending against the other's.

Abbott v. DexCom is the continuous-glucose-monitoring equivalent. Abbott is the more active of the pair here (34 cases on the claimant side), and the rivalry, which included a Paris Local Division ruling that invalidated a DexCom patent for lack of inventive step, resolved in a global, multi-jurisdiction settlement. The UPC was one theatre in a worldwide campaign the parties chose to end everywhere at once.

A third, lower-volume rivalry is Fujifilm v. Kodak in printing and imaging, the same dispute that produced the UPC's landmark long-arm-jurisdiction ruling.

The rise of NPEs

When the UPC opened, a common prediction was that it would become a magnet for non-practising entities seeking pan-European injunctions. The prediction was slow to arrive and is now visibly coming true, led by the party second on our table.

Network System Technologies, the first NPE to sue at the UPC, brought semiconductor-patent infringement actions in Munich against Texas Instruments, Audi and Volkswagen in early 2024, and later against Samsung and Qualcomm over the same patents (JUVE Patent). Its high respondent-side count is the tell: those targets fired back with revocation counterclaims, so an entity that exists to assert appears, on a case count, to spend much of its time defending. Volkswagen and Texas Instruments rank where they do partly because they were on the receiving end of exactly this kind of chip litigation. Most of the assertion entities now active at the UPC are US-based.

What this means for practitioners

If you are pricing a dispute against one of these repeat players, the claimant-to-respondent ratio tells you something the case caption does not: posture.

• Read the opponent's stance before you file or answer. A claimant-heavy SEP holder running a campaign (Huawei, Ericsson, Nokia) likely has parallel actions and a settlement number in mind; a respondent-heavy implementer (Xiaomi, Samsung, Motorola) is defending incoming suits and will fight on validity and FRAND. Posture predicts the playbook.
• Count the corporate group, not the entity. Because subsidiaries litigate separately, the defendant on your matter may be one node of a family already deep in UPC litigation elsewhere. Aggregate before you judge how battle-tested, and how settlement-minded, the other side is.
• In a two-front operating-company war (Edwards and Meril, Abbott and DexCom), expect mirrored escalation. Each patent asserted invites a counter-assertion; these rivalries tend to resolve as packages, often by global settlement, not patent by patent.
• For NPE matters, the revocation counterclaim is the lever. The respondent-side counts on the assertion entities are the counterclaims their targets filed, the most reliable pushback an operating company has and frequently the path to settlement.

What to watch

Three things will reshape these rankings as the court moves through its fourth year. First, settlement velocity: several of the biggest case generators, Panasonic's campaign against Xiaomi and OPPO among them, resolved by settlement, which means today's most active litigant can drop off the table in a single quarter. Second, the NPE share: if the assertion-entity cohort behind Network System Technologies keeps growing, the top of the table will tilt further toward licensing campaigns and away from operating-company disputes. Third, the SEP and FRAND venue question: every clarification on whether and how the UPC sets FRAND terms changes the calculus for the licensors filing campaigns and the implementers deciding whether to fight or take a licence. We update these counts as new decisions are classified.

Want the full case profile for a specific party, with the divisions and outcomes behind the counts? That is exactly what our entity analytics are built to surface.

Related reading

• UPC Firm Scorecards: Who's Winning the Most Patent Battles in Europe
• Meet the Judges of the UPC: Panel Composition & Ruling Tendencies
• The UPC's First Permanent SEP Injunction: Philips v. Belkin & the FRAND Landscape

Sources

• McDermott Will & Emery — "UPC Issues First FRAND Decision": https://www.mwe.com/insights/upc-issues-first-frand-decision/
• A&O Shearman — "UPC ruling on Panasonic v. Oppo: a landmark decision on SEPs and FRAND": https://www.aoshearman.com/en/insights/upc-ruling-on-panasonic-v-oppo-a-landmark-decision-on-seps-and-frand
• JUVE Patent — "Panasonic's global SEP battle with Xiaomi and Oppo": https://www.juve-patent.com/cases/panasonics-global-sep-battle-with-xiaomi-and-oppo-kicks-into-high-gear/
• JUVE Patent — "First NPE lawsuits over semiconductor patents reach the UPC": https://www.juve-patent.com/cases/first-npe-lawsuits-over-semiconductor-patents-reach-the-upc/
• UPClytics.com — internal dataset of classified UPC decisions (snapshot June 2026).