These large UK companies are primarily in telecommunications, financial services, and information technology. Vodafone and BT Group are major telecommunications providers. RELX specializes in information-based analytics, and LSEG offers financial indexing and analytic services. Revolut is a fintech company, and Sage provides business software.
Most of these companies are headquartered in London, including Vodafone, BT Group, RELX, LSEG, and Revolut. Other headquarters include Middlesex for Sky, Windsor for Centrica and British Gas, Newcastle upon Tyne for Sage, Cardiff for Admiral Group Plc, and Crawley for Ambius United Kingdom. The companies were founded between 1980 and 2017.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Vodafonevodafone.com
Using technology to connect people globally, drive social change, and improve lives while emphasizing the importance of humanity and collaboration |
142,740 | |||
| 2 | 73,712 | ||||
| 3 | 37,600 | ||||
| 4 | 35,346 | ||||
| 5 | 25,298 | ||||
| 6 |
Revolutrevolut.com
A fintech company on a mission to provide customers with more visibility, control, and freedom over their money through innovative products |
18,462 | |||
| 7 |
Centricacentrica.com
A leading energy services provider with a focus on sustainability, offering zero carbon electricity to millions of customers through various brands |
18,164 | |||
| 8 | 15,616 | ||||
| 9 |
Pearsonpearson.com
A global leader in learning, offering digital content, assessments, qualifications, and data to create vibrant and enriching learning experiences worldwide |
13,596 | |||
| 10 |
Ambius United Kingdomambius.co.uk
Global provider of plants, replica foliage, and flowers for commercial spaces, offering interior landscaping, exterior landscaping, floral arrangements, artificial plants, and art rentals |
13,201 | |||
| 11 |
Finastrafinastra.com
Focusing on OPEN Collaboration & Finance, Finastra provides innovative technology solutions for global financial services, promoting financial inclusion and diversity |
12,499 | |||
| 12 | 12,146 | ||||
| 13 |
Clarivateclarivate.com
A global information services provider connecting people and organizations to trusted intelligence in Academia & Government, Life Sciences & Healthcare, and Intellectual Property |
11,385 | |||
| 14 |
Admiral Group Plcadmiralgroup.co.uk
Leading car insurance provider in the UK and 7 other countries, focusing on innovation, customer service, and employee satisfaction. |
11,047 | |||
| 15 |
British Gasbritishgas.co.uk
Providing affordable energy services and support to millions of UK homes and businesses, focusing on saving energy and money. |
10,311 | |||
| 16 |
BSIbsigroup.com
A global organization with over 100 years of experience in shaping best practices, helping businesses achieve excellence, competence, and sustainable growth |
9,882 | |||
| 17 |
Financial Timesft.com
provides authoritative, accurate business news and information with a large digital subscription base, serving the global business community. |
9,092 | |||
| 18 |
Nuffield Healthnuffieldhealth.com
Leading UK not-for-profit healthcare organization, investing all income back into hospitals, fitness clubs, and wellbeing services to build a healthier nation. |
9,066 | |||
| 19 |
Allianz UKallianz.co.uk
Global financial services provider offering commercial and personal insurance products through brokers, focusing on employee growth, diversity, and sustainability for a better future |
8,735 | |||
| 20 |
ACCAaccaglobal.com
A global body for professional accountants, providing qualifications and support while promoting ethics, governance, and public interest in the profession |
8,556 | |||
| 21 |
Oxford University Pressoup.com
An institution part of the University of Oxford with a 500-year history of providing high-quality research and education resources globally |
8,246 | |||
| 22 |
Virgin Activevirginactive.co.uk
Operates large health clubs offering diverse fitness products and services, inspiring active lifestyles with personalized gym and boutique experiences. |
7,690 | |||
| 23 | 7,630 | ||||
| 24 |
The Access Grouptheaccessgroup.com
It provides business management software solutions for small and mid-sized organizations, enhancing productivity through innovative cloud and AI technologies. |
7,368 | |||
| 25 |
David Lloyd Clubsdavidlloyd.co.uk
Largest European health and fitness group operating clubs with gyms, pools, racquet sports, spas, kids facilities, and social spaces for families. |
6,843 | |||
| 26 |
The Economisteconomist.com
Global news and analysis provider helping individuals understand the world; offering subscriptions for in-depth insights and respecting personal data privacy |
6,694 | |||
| 27 |
Soho House & Cosohohouse.com
Private members' clubs for creative industries featuring houses, restaurants, cinemas, spas, and workspaces across Europe and North America for networking and social growth. |
6,509 | |||
| 28 |
Formula 1formula1.com
Delivering Formula 1's global spectacle through technical infrastructure, data analysis, content production, hospitality programs, and innovative marketing to engage fans worldwide |
6,081 | |||
| 29 |
OnlyFansonlyfans.com
A platform empowering creators to express themselves, monetize content, and build connections with fans in a safe and inclusive environment |
5,941 | |||
| 30 |
IONiongroup.com
Innovative company providing trading and workflow automation software to financial institutions, corporations, and governments, empowering decision-making and accelerating processes |
5,591 | |||
| 31 |
Sophossophos.com
A global cybersecurity leader offering advanced solutions, managed services, and a broad portfolio of technologies to protect organizations from cyberattacks worldwide |
5,498 | |||
| 32 |
Manchester Unitedmanutd.com
Global football club with 146-year heritage, 68 trophies, and a passionate worldwide community generating revenue through sponsorships and merchandising. |
5,391 | |||
| 33 |
Pets at Homepetsathome.com
Leading UK petcare retailer with stores, grooming salons, veterinary practices, and dedicated colleagues focused on animal welfare and customer service. |
5,381 | |||
| 34 |
O2 (Telef贸nica UK)o2.co.uk
Leading UK mobile network operator providing 2G to 5G services, retail stores, WiFi, and partnerships with Tesco Mobile and entertainment venues. |
5,371 | |||
| 35 |
Everyone Active - SLMeveryoneactive.com
This company specializes in managing local authority leisure contracts, focusing on delivering high-quality services and increasing community participation |
5,340 | |||
| 36 |
Sapienssapiens.com
Global leader providing intelligent software solutions for insurers, empowering them with AI and automation across property, casualty, and life insurance operations. |
5,271 | |||
| 37 | 5,267 | ||||
| 38 |
LSEG Data & Analyticslseg.com
A global provider of financial markets data and infrastructure, enabling customers to gain insights through data, feeds, analytics, and workflow solutions |
5,147 | |||
| 39 |
Fitness AIguden.org
Fitness AI is a mobile app using artificial intelligence to personalize workout plans, track progress, and motivate users towards achieving health and fitness goals |
5,137 | |||
| 40 |
Utility Warehouseuw.co.uk
A growing business focusing on simplifying utilities and providing personalized service to help people spend more time on important things |
5,083 | |||
| 41 |
YouGovyougov.com
An international online research and analytics technology group providing unparalleled consumer insights for brands, media owners, and agencies worldwide |
4,691 | |||
| 42 | 4,204 | ||||
| 43 |
Fitch Group, Inc.fitch.group
Global leader in financial information services with operations in 30+ countries Offers credit ratings, research, risk solutions, training, and venture investments Dual headquarters in London and New York |
4,203 | |||
| 44 |
DAZNdazngroup.com
Global sports media innovators using cutting-edge technology to revolutionize the industry, providing sports streaming services and fostering an inclusive, diverse work environment |
4,092 | |||
| 45 |
Futurefutureplc.com
Global specialist media platform creating expert original content through websites, magazines, events, and social spaces reaching millions. |
3,900 | |||
| 46 |
Boots Opticiansboots.com
Providing extensive eyecare services and a wide range of designer glasses and contact lens plans across numerous UK stores. |
3,710 | |||
| 47 |
Taylor & Francis Grouptaylorandfrancis.com
A leading publisher of scholarly content in Humanities, Social Sciences, Science, and Medicine, partnering with researchers and institutions worldwide for knowledge dissemination |
3,598 | |||
| 48 | 3,597 | ||||
| 49 |
Infobipinfobip.com
Global leader in omnichannel engagement, providing messaging tools and solutions for customer engagement, authentication, and security with a strong focus on quality engineering |
3,501 | |||
| 50 |
TryHackMetryhackme.com
It simplifies learning and teaching Cybersecurity through prebuilt courses and cloud-hosted virtual machines, ideal for CTFs, workshops, and training. |
3,445 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 51 | 3,323 | ||||
| 52 |
Arsenal Football Clubarsenal.com
Professional football club focusing on winning trophies, developing youth talent, community involvement, maintaining a magnificent stadium, and self-financing operations. |
3,285 | |||
| 53 | 3,161 | ||||
| 54 |
Civicacivica.com
The company creates software solutions for delivering essential services to people globally |
3,116 | |||
| 55 |
Accelyaw3.accelya.com
A global software provider for airlines, empowering over 200 airlines with innovative solutions to drive growth, enhance customer experience, and control retailing operations |
3,080 | |||
| 56 |
Claranetclaranet.com
A global technology services provider offering managed services, professional services, and training in Cloud, Networks, Cyber Security, and Workplace technologies since 1996 |
3,073 | |||
| 57 |
Dentistrydentistry.co.uk
Leading UK dental website & magazine providing industry news, education, analysis, clinical insights, business tips, and product information for dental professionals |
3,066 | |||
| 58 |
Genius Sportsgeniussports.com
This company delivers technology and expertise to sports, betting, and media partners worldwide, enhancing data collection, fan engagement, and overall performance |
3,054 | |||
| 59 |
IRIS Software Groupiris.co.uk
Leading provider of integrated software solutions and services to help organizations make better business decisions, minimize admin, and improve efficiency across various industries. |
3,041 | |||
| 60 |
The Guardiantheguardian.com
A leading publisher of theguardiancom, Guardian US, and Guardian Australia, known for agenda-setting journalism and investigative reporting worldwide |
2,944 | |||
| 61 |
Peninsula UKpeninsulagrouplimited.com
Provides employment law, HR, and health & safety services, including training, tax, payroll, software, and employee assistance programs to businesses. |
2,888 | |||
| 62 |
TradingViewtradingview.com
Social network and charting platform for traders and investors, used by 50 million+ users worldwide with open source charts used by financial giants |
2,761 | |||
| 63 |
GlobalData Plcglobaldata.com
A leading information services company helps organizations and decision-makers predict the future, make informed decisions, and gain a competitive edge |
2,711 | |||
| 64 |
Vitalityvitality.co.uk
This company offers health insurance, life insurance, and investments that reward healthy lifestyle choices, leading to a longer, healthier, and financially secure life |
2,671 | |||
| 65 |
Darktracedarktrace.com
AI cybersecurity platform learns unique data, detects threats, and intervenes against attacks, protecting organizations worldwide from cyber-threats. |
2,632 | |||
| 66 |
NCC Groupnccgroupplc.com
Cybersecurity firm advising global organizations on protecting data and systems, with expertise in assessing, mitigating, and responding to cyber threats Offices worldwide |
2,617 | |||
| 67 |
Gammagammagroup.co
Gamma is a leading supplier of Unified Communications services in the UK, Germany, Spain, and Benelux, offering robust solutions for communication and collaboration |
2,588 | |||
| 68 | 2,522 | ||||
| 69 |
Wood Mackenziewoodmac.com
Provider of data, analytics, and consultancy services for renewables, energy, and natural resources sectors supporting investment decisions. |
2,472 | |||
| 70 |
Keyloopkeyloop.com
Global automotive technology company delivering cutting-edge solutions for auto retailers and OEMs, connecting them to consumers through innovative technology and distinctive customer experiences |
2,435 | |||
| 71 |
Mimecastmimecast.com
Protects humans, data, and AI agents through a unified platform, securing the workforce and their interactions with AI from cyberattacks. |
2,396 | |||
| 72 |
Hack The Boxhackthebox.com
Leading platform enhancing organizational cyber resilience, battle-testing and upskilling humans and AI agents through real-world scenarios and gamified labs. |
2,309 | |||
| 73 |
The Gym Groupthegymgroup.com
Provides affordable, 24/7 gyms across the UK with a focus on accessibility, community health, and member satisfaction. |
2,296 | |||
| 74 |
Ocado Retailocadoretail.com
Dedicated online supermarket offering unbeatable choice, excellent service, and good value to customers seeking convenient grocery shopping. |
2,292 | |||
| 75 |
Cineworld Cinemas Ltdcineworld.com
This company provides an unparalleled cinema experience in the UK & Ireland with over 100 cinemas, offering special formats like IMAX and 4DX |
2,245 | |||
| 76 |
Medivet & Partnersmedivetgroup.com
A community of passionate veterinary professionals dedicated to providing exceptional care, top-rated customer service, and continuous learning opportunities in the industry |
2,227 | |||
| 77 |
OneAdvancedoneadvanced.com
Provider of sector-focused business software and services supporting millions of users across healthcare, education, legal, and public sectors in the UK. |
2,179 | |||
| 78 |
Euromonitor Internationaleuromonitor.com
Provides comprehensive global data analytics and research on markets, industries, economies, and consumers to support strategic business growth decisions. |
2,176 | |||
| 79 |
SunLife UKsunlife.co.uk
Providing support and services tailored for individuals aged 50 and above to enhance life quality and enjoyment. |
2,164 | |||
| 80 | 2,102 | ||||
| 81 |
Unisonunison.org.uk
This organization is the UK's largest union, providing support, benefits, and services to over 13 million members across various sectors |
2,078 | |||
| 82 |
Places Leisureplacesleisure.org
A social enterprise managing leisure facilities for local authorities, promoting active lifestyles, healthy communities, and exceeding expectations through partnerships and dedicated teams |
2,050 | |||
| 83 |
Explore Learningexplorelearning.co.uk
A leading provider of after-school tuition for 4-16 year olds in the UK, focused on building confident learners hungry for knowledge |
2,032 | |||
| 84 |
Argus Mediaargusmedia.com
Provides price assessments, news, analytics, consulting, data tools, and conferences for global energy and commodity market transparency and decision-making. |
2,024 | |||
| 85 |
Chartered Institute of Arbitrators (Ciarb)ciarb.org
A charitable organization promoting effective resolution of disputes worldwide through arbitration, mediation, and adjudication with a focus on empowering best practices |
2,006 | |||
| 86 |
Canonicalcanonical.com
Publishing Ubuntu, popular enterprise Linux, open source delivery, cloud to edge, secure, cost-effective, global community, developer platform, remote-first company. |
2,001 | |||
| 87 |
Eurosportwbdsports.com
Leading sport destination in Europe with a focus on live streaming, Olympic coverage, cycling, tennis, and winter sports events, and online sports news |
1,989 | |||
| 88 |
Info-Tech Research Groupinfotech.com
This company provides unbiased, highly relevant IT research and tools to help CIOs and IT leaders make strategic, informed decisions for their organizations |
1,964 | |||
| 89 |
MICHELIN Connected Fleetconnectedfleet.michelin.com
Provide tools and data-driven recommendations to fleet operators for cost reduction, productivity improvement, driver safety, and sustainable fleet management. |
1,961 | |||
| 90 |
The Business of Fashionbusinessoffashion.com
A global fashion media company providing industry insights, resources, events, and online learning for fashion professionals, students, and entrepreneurs worldwide |
1,949 | |||
| 91 |
Institution of Engineering and Technology (IET)theiet.org
A global engineering institution with 154,000 members in 148 countries, inspiring and influencing engineers worldwide to create a better world |
1,940 | |||
| 92 |
AMamdigital.co.uk
Enriching research and teaching with digitized historical and cultural collections from libraries and archives worldwide, offering award-winning resources and education |
1,834 | |||
| 93 |
Tottenham Hotspur Football Clubtottenhamhotspur.com
A world-famous football club based in London, competing in the English Premier League with a strong business model and world-class facilities |
1,827 | |||
| 94 |
E.ON Nexteonnext.com
Helping customers reduce energy bills and environmental impact by facilitating the energy transition and promoting CO2 savings in the UK. |
1,792 | |||
| 95 |
Tatetate.org.uk
A public institution with four major galleries showcasing British and international art to increase public enjoyment and understanding |
1,743 | |||
| 96 |
Autotradercareers.autotrader.co.uk
Leading UK automotive marketplace connecting buyers and sellers of cars, e-bikes, caravans, simplifying complex vehicle purchasing journeys. |
1,706 | |||
| 97 |
Warrington Borough Councilwarrington.gov.uk
Local government focused on economic growth, social inclusion, community resilience, workforce wellbeing, and supporting vulnerable populations within the borough. |
1,680 | |||
| 98 |
Freedom Leisurefreedom-leisure.co.uk
A charitable leisure trust promoting healthy lifestyles through over 100 venues in England and Wales, offering affordable, accessible facilities for all |
1,675 | |||
| 99 |
Hotel Chocolathotelchocolat.com
Luxury British cacao grower and chocolatier focusing on originality, authenticity, and ethics, with eco-conscious practices and innovative farming initiatives |
1,648 | |||
| 100 |
Novakid Incnovakidschool.com
An innovative online learning platform offering English lessons for kids, combining game-based methods, AI technology, and immersive experiences for diverse learning needs |
1,622 | |||
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How this list is built
Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.
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