The 20 Most Active Litigants at the Unified Patent Court

A small set of repeat players drives a large share of the Unified Patent Court's docket. Across the cases in our database — every claimant and respondent appearance our platform has classified through mid-2025 — we track close to 1,900 distinct parties, and roughly a quarter of them appear exactly once. But the most active UPC litigants, perhaps two dozen names, account for a disproportionate share of the activity, and one of them — counting all its national subsidiaries together — has been named in more than 500 case appearances on its own.

That name is Xiaomi, and the way it shows up is the first lesson in reading these rankings: the same corporate group litigates under many flags. This is our read on who the UPC's repeat players are, what posture each takes — claimant or respondent, patent owner or accused infringer — and the patterns those appearances reveal.

The most active UPC litigants, by appearance count

The table below ranks the busiest entities by total appearances (claimant plus respondent) across the cases we have classified. "As claimant" counts how often the party brought or pursued an action; "as respondent," how often it was on the receiving end. A single party often sits on both sides across its portfolio, because a defendant in an infringement action routinely counterclaims for revocation, and a patentee sued for revocation defends and counter-asserts. These are public-record litigation appearances; "NPE" (non-practising entity) is a neutral descriptor for a company that licenses and asserts patents rather than making products — not a judgement on any case.

Counts are claimant/respondent appearances across the cases our platform has classified through mid-2025; an appearance is not the same as a distinct lawsuit, because one dispute can generate an infringement action, a revocation counterclaim, and procedural sub-applications, each adding appearances.

A note on subsidiaries. Large groups litigate through many national entities, and the data records each one separately. Xiaomi is the clearest case: its German, Dutch, French, Italian, Swedish, Hong Kong and Beijing units each appear in our corpus, and the single most-named entity above — the Dutch Xiaomi company, with 74 respondent appearances — is only one slice of it. Collapse the whole Xiaomi family into one combatant and it tops any UPC activity ranking by a wide margin, almost entirely as a respondent. The same caveat applies, more modestly, to Meril (two entities), Kodak (three), Huawei and OPPO. Read the table as the shape of the docket, not a precise league table of corporate groups.

SEP holders versus implementers: the telecoms war

The largest single pattern is the standard-essential-patent (SEP) fight between cellular-technology licensors and the smartphone makers who implement their standards. On one side, the patent owners — Panasonic (62 claimant appearances), Huawei, Ericsson, Nokia, Philips. On the other, the implementers who show up overwhelmingly as respondents — the Xiaomi entities, OPPO/OROPE, Motorola Mobility, ASUSTek.

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 EP 2 568 724 and granting an injunction across Germany, France, Italy, Sweden and the Netherlands, plus €250,000 in provisional damages — even though the parties had, in principle, already agreed to settle globally the month before (McDermott, "UPC Issues First FRAND Decision"). Panasonic ran roughly a dozen UPC actions against OPPO and Xiaomi from a single campaign, which is exactly why one claimant generates dozens of appearances. A SEP holder's count is a campaign signature, not a count of disputes: a handful of patents against a handful of implementers, multiplied across divisions and counterclaims, fills a large block of the table.

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. Two such wars dominate the rankings.

Edwards Lifesciences v. Meril is the transcatheter-heart-valve (TAVI) fight. Edwards (43 claimant / 45 respondent appearances) and Meril (both entities together, roughly 50 claimant / nearly 100 respondent) have produced a string of UPC actions over prosthetic heart valves and delivery systems. The Munich Local Division granted Edwards an injunction on EP 3 646 825, with product recall and destruction, rejecting Meril's jurisdiction, validity and public-interest defences; a second injunction followed in 2025 on a further heart-valve patent, and a third resolution came by court-enforceable settlement. The near-symmetry of each side's counts is the signature of a true two-front war — each company simultaneously asserting its own patents and defending against the other's.

Abbott Diabetes Care v. DexCom is the continuous-glucose-monitoring (CGM) equivalent. Abbott (48 claimant) and DexCom (22/24) ran a multi-jurisdictional fight that included a Paris Local Division ruling invalidating DexCom's EP 3 435 866 for lack of inventive step, before settling globally with a ten-year, zero-royalty patent peace and no payments either way (Abbott's settlement announcement). Here 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 (Fujifilm 32 claimant; the three Kodak entities heavily on the respondent side) — the same dispute that produced the UPC's landmark long-arm-jurisdiction ruling in Düsseldorf.

The rise of NPEs at the UPC

When the UPC opened, a common prediction was that it would become a magnet for non-practising entities seeking pan-European injunctions. The data shows that prediction coming true, led by the entity at the top of our table.

Network System Technologies LLC (50 claimant / 43 respondent) was the first NPE to sue at the UPC — bringing semiconductor-patent infringement actions in Munich against Texas Instruments, Audi and Volkswagen in early 2024, and later against Qualcomm and Samsung over the same patents. Its high respondent count comes from the revocation counterclaims those targets filed in return; the Munich Local Division ultimately rejected several of NST's suits, and the campaign wound down through settlements. Volkswagen's respondent appearances in our table are partly a product of being on the receiving end of exactly this kind of NPE chip litigation. Behind NST, a cohort of assertion entities has built a visible UPC footprint:

• Headwater Research (24 / 10) — Texas-based; a wireless-patent campaign against Samsung run in parallel in the Eastern District of Texas and the UPC.
• Suinno Mobile & AI (21 / 13) and Sun Patent Trust (21 / 11) — repeat claimants in the mobile and cellular space.
• Centripetal (18 / 3) — a near-pure claimant posture (cybersecurity patents).
• InterDigital VC Holdings (11 / 5), with several affiliated InterDigital entities adding more — the SEP-licensing model in NPE form.
• Shamrock Mobile and Odiporo (each 31 respondent appearances) — entities that sit predominantly on the defending side, a reminder that the NPE label spans very different litigation roles.

The pattern across the NPE cohort is a claimant-heavy posture — they exist to assert — but with substantial respondent counts driven by the revocation counterclaims their targets reflexively file. NPEs have become a large and growing presence at the UPC, most of the top European assertion entities US-based, and our appearance data is what that trend looks like at the party level.

What this means for practitioners

If you are pricing a dispute against one of these repeat players, the appearance count tells you something the case caption does not: posture.

• Profile the opponent's stance before you file or answer. A claimant-heavy SEP holder running a campaign (Panasonic, Huawei, Ericsson) likely has parallel actions and a settlement number in mind; a respondent-heavy implementer (Xiaomi, OPPO, 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 are litigated separately, the defendant on your matter may be one node of a group already deep in UPC litigation elsewhere. Aggregate the family before judging how battle-tested — and how settlement-minded — the other side is.
• In a two-front operating-company war (Edwards/Meril, Abbott/DexCom), expect mirrored escalation. Each patent you assert invites a counter-assertion; these rivalries resolve as packages, often by global settlement, not patent-by-patent.
• For NPE matters, the counterclaim is the lever. The respondent counts on NST, Headwater and the rest are revocation counterclaims — the most reliable pushback operating companies have, and frequently the path to settlement.

What to watch

Three things will reshape these rankings as the UPC moves through its third year. First, 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. Second, the SEP/FRAND venue question — every clarification on whether and how the UPC sets FRAND terms changes the calculus for both the licensors filing campaigns and the implementers deciding whether to fight or take a licence. Third, settlement velocity — several of the biggest appearance-generators (Panasonic/OPPO, Abbott/DexCom, NST/Samsung) resolved by settlement, which means today's most active litigant can exit the rankings in a single quarter. We update these counts as new decisions are classified.

Want to see the full appearance profile for a specific party, including 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/
• Abbott — "Abbott Agrees to Global Continuous Glucose Monitoring Litigation Settlement with Dexcom": https://abbott.mediaroom.com/Abbott-Agrees-to-Global-Continuous-Glucose-Monitoring-Litigation-Settlement-with-Dexcom
• UPClytics.com — internal dataset of classified UPC decisions (snapshot June 2026 build).