These London-based companies operate in the Technology, Information, and Media sectors. They include large established firms as well as mid-sized companies. The oldest companies listed here are Reach plc, founded in 1832, and Aspermont Limited, founded in 1835.
RELX provides information-based analytics, while Digital Marketing Awards focuses on financial marketing. The Business of Fashion is a global fashion media company, and ESL FACEIT Group - EFG specializes in competitive games and esports.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 | 37,600 | ||||
| 2 |
Digital Marketing Awardscloudlondon.org
A financial marketing firm helping financial services companies improve their online presence to attract, convert, and retain clients through customized marketing services |
2,246 | |||
| 3 |
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 | |||
| 4 |
Reach plcreachplc.com
Largest UK and Ireland commercial news publisher connecting audiences through over 120 brands including national, local, and US titles. |
1,756 | |||
| 5 |
ESL FACEIT Group - EFGeslfaceitgroup.com
Leading competitive games and esports company helping brands engage youth audiences through authentic activation, creating community beyond gameplay |
1,412 | |||
| 6 |
BMJbmjgroup.com
Global healthcare knowledge provider improving patient outcomes through evidence, decisions, systems, prioritizing inclusion, diversity, anti-racism, and equity. |
1,281 | |||
| 7 |
Time Outtimeout.com
Global brand curating city lifestyle content and operating editorially curated food and cultural markets in multiple international cities. |
735 | |||
| 8 |
Outraoutra.co.uk
A leading data and analytics company using proprietary data and expert modeling to help brands acquire and retain quality customers |
497 | |||
| 9 |
Merzigomerzigo.com
Cutting-edge video monetization services for broadcasters, producers, and distributors, helping entertainment brands grow AVOD business, reach new audiences, and boost revenue |
383 | |||
| 10 | 373 | ||||
| 11 |
The Drumthedrum.com
This company provides content on modern marketing, agency business, creativity, and the future of media to help global marketers make better decisions |
240 | |||
| 12 |
Aspermont Limitedaspermont.com
A leading media services provider specializing in B2B content for global resource industries, offering data and services products to a blue-chip client base |
175 | |||
| 13 |
nativepartner.native.fm
Campus media specialists connecting brands with students through exclusive partnerships with Students’ Unions, offering unique insight into student culture |
169 | |||
| 14 |
Sataliasatalia.com
Utilizing cutting-edge technologies, the company builds AI systems to solve complex efficiency challenges for various industries, including route optimization and demand forecasting |
169 | |||
| 15 |
Social Value Portalsocialvalueportal.com
Empowers organizations to measure, manage, and report their social contributions, utilizing a robust standard and extensive data to ensure compliance and prevent social washing. |
115 | |||
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. | |||||
| 16 |
Themiswearethemis.com
An award-winning technology platform assisting clients in managing financial crime risk exposure effectively |
106 | |||
| 17 |
Vyntelligencevyntelligence.com
Digital platform using smart data capture and AI insights to transform complex analog work, empowering users to make faster, more informed decisions for improved outcomes |
97 | |||
| 18 |
Brantial Türkiyebrantial.ai
A leading provider of packaging solutions, specializing in PET preforms, bottles, closures, extrusion, and thermoforming for various industries domestically and internationally |
77 | |||
| 19 |
Hyperlayerhyperlayer.com
Enabling financial institutions with a secure platform and orchestration layer for designing and scaling personalized financial experiences without replacing core systems. |
71 | |||
| 20 | 44 | ||||
| 21 |
Direct On Demandsdirectondemands.com
Global leader in B2B lead generation, offering sales support through results-driven solutions in lead generation, database solutions, and display advertising worldwide |
41 | |||
| 22 | 40 | ||||
| 23 |
Piccadilly Circusmsdevs.org
The QA Engineer Community is a global group of QA engineers who support each other through resources, forums, meetups, and projects |
35 | |||
| 24 | 32 | ||||
| 25 | 28 | ||||
| 26 | 24 | ||||
| 27 |
Aura Commoditiesauracommodities.com
Harnessing powerful interface for visualizing worldwide commodity weather risk and data, Aura provides insights for smarter, data-driven decisions on various agricultural commodities |
21 | |||
| 28 |
Op2mise.aiop2mise.ai
Media solutions experts providing best-in-class software solutions to empower clients and drive efficiency, growth, and strategic success through innovative approaches |
14 | |||
| 29 |
The Stackthestack.technology
A technology publication featuring interviews and insight on digital innovation, policy, and industry changemakers, focusing on IT roles and community support |
14 | |||
| 30 |
Reppedrepped.co.uk
A platform empowering media buyers to initiate sales with reps and vendors, fostering immediate connections for efficient planning and relationship-building |
6 | |||
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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 15, 2026.
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