The UK’s patent prosecution landscape is led by a group of highly experienced firms, each bringing a unique blend of technical expertise, sector focus, and global client networks.

Marks & Clerk tops the chart with over 18,000 filings, a testament to its enduring presence, full-service model, and longstanding international relationships. The firm remains a go-to partner for both high-volume EP validation work and complex domestic filings in sectors like medtech, telecom, and software.

Dehns, with more than 18,000 filings as well, demonstrates its strength in managing large portfolios for foreign corporates with major coverage in the United States. Despite a modest decline in filings, Dehns continues to hold its place as a cornerstone firm in the market, holding the number two position consecutively over the five year time frame.

Mewburn Ellis LLP, HGF Limited, and Murgitroyd & Company round out the top five. Notably:

• Mewburn Ellis remains steady with a strong focus in the Pharmaceuticals and Biotechnology technical areas, with filings coming from a majority of their top Japanese clients.
• HGF Limited’s performance remains consistent and reinforces its reputation for a multi-disciplinary approach, especially in pharma, medtech, and computer technology portfolios.
• Murgitroyd & Company showed a strong 30% increase in filings of the time period, suggesting successful client acquisition efforts and perhaps stronger referral flows from overseas partners.

Further down the list, firms like Venner Shipley (26% increase in published filings from 2021-2025), Mathys & Squire (42% increase in published filings), and Boult Wade Tennant (10% increase in published filings) maintain high relevance. They may not lead by raw volume but are posting strong growth.

Also notable is Lewis Silkin LLP with an impressive 252% increase in published filings. While primarily a Trademark firm, it seems that they are starting to show interest in adding patent filings to their portfolio.

What’s the bigger story?

A single player does not dominate the UK; competition is fierce and distributed. The presence of numerous firms filing between 5,000 and 10,000 filings suggests a dynamic and diversified ecosystem where technical authority, responsiveness, and international alignment are key differentiators.

The 2021–2025 period saw fluctuations shaped by global factors, from pandemic-related delays to economic recalibration, but overall, the market showed stability and long-term resilience.

• The majority of top firms maintained or grew their volume year-over-year, especially in the post-pandemic years of 2023–2025.
• Firms such as Marks & Clerk, Murgitroyd, Kilburn & Strode, and Mathys & Squire all posted double-digit growth, reflecting increased foreign-originating filings, particularly from Asia and North America.

The broader trend is a return to growth and confidence in the UK IP environment, despite external uncertainty around Brexit, UPC developments, and global supply chain disruptions.

A significant volume of patent cases continues to flow into the UK, led by the United States with over 59,000 cases, accounting for a substantial share of all inbound filings. The next-largest contributors are Japan (41,012), China (28,628), and South Korea (19,689), solidifying the UK’s importance to some of the most IP-intensive economies in the world.

This sustained inbound activity points to the UK’s relevance in:

• PCT national phase entries, often coordinated through European regional strategies
• EP validations, where UK-specific protection remains essential post-Brexit
• Direct UK national filings, particularly in high-tech, biotech, and pharmaceuticals

The presence of filings from countries such as Canada, Israel, and Australia highlights the UK’s appeal to emerging tech players and innovative SMEs worldwide.

UK-based applicants continue to file actively across global jurisdictions, with the United States again taking the lead as the top destination for UK-originating patents (15,255 cases). China (9,657) and Japan (5,642) follow, reflecting the growing strategic importance of Asian markets for British innovators.

Other key filing destinations include:

• Canada (5,065) and Australia (4,186) – two established Commonwealth markets with strong IP frameworks
• South Korea (3,836) and India (3,114) – both reflecting increasing collaboration and IP enforcement opportunities in Asia
• Brazil, Mexico, and Vietnam – suggesting proactive strategies by UK firms to secure protection in fast-growing innovation economies

The wide geographic distribution of outbound filings suggests a globally minded filing strategy and the increasing competitiveness of UK-originated innovation.

The UK’s role in international patent case exchange underscores the country’s strong relevance in the global IP landscape. For UK law firms and foreign associates alike, this presents an opportunity to:

• Build cross-border alliances with firms in top sending and receiving countries
• Enhance value propositions to overseas clients seeking a trusted UK partner
• Support British innovators as they expand into growth markets with robust outbound strategies

For international law firms considering an expansion or stronger relationships with firms or applicants in the UK, here are a few takeaways:

• The UK is not oversaturated, just competitive. While top firms handle a large share of filings, the breadth of high-performing mid-tier firms suggests there is still room for differentiation, especially through specialization, digital efficiency, and cross-jurisdictional integration.
• EP validation and PCT national phase work remains core. UK firms continue to attract substantial volume through strategic global partnerships.
• Strategic partnerships matter. Firms looking to build presence in the UK should prioritize long-term referral partnerships and explore partnerships with technically aligned British firms.

The UK patent landscape is marked by strong leadership at the top, rising challengers in the middle, and consistent international demand. Whether you’re a global firm looking to establish a presence or a domestic firm eyeing international expansion, the data shows that the UK remains fertile ground for growth in patent services.