Company lists · Data refreshed September 2026

Top 25 Media buying platforms based in London, United Kingdom

Name: Media buying platforms based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 5, 2026 1,017 companies tracked

RevenueBase identified 1,017 media buying platforms headquartered in London, United Kingdom as of September 2026 and tracks 25,716 professional contacts across them, including 4,325 with verified work emails. London is the largest hub.

This list covers media buying platforms headquartered in London, United Kingdom, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review

1,017Companies

25,716Contacts tracked

4,325Verified emails

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The 25 largest media buying platforms based in London, United Kingdom

Ranked by team size

Top 25 of 1,017 media buying platforms based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names media buying platforms: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#	Company	Headquarters	Employees	Contacts
1	Publicis MediaPartial evidence	London, United KingdomHQ checked Sep 5, 2026	10001+	6,901
	“Publicis Media harnesses the power of modern media through leading agency brands Dysrupt, Infinite Roar, Publicis Collective, Publicis Health Media, Spark Foundry, Starcom and…” Source: company website · checked Sep 5, 2026
2	M C Saatchi PerformancePartial evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	457
	“We are a Global digital media agency specializing in taking a human approach to connecting brands with people across all channels.” Source: company website · checked Sep 5, 2026
3	The7starsPartial evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	295
	“the7stars is the UK’s largest independent media agency, offering the best people, the best service and the best creative media campaigns.” Source: company website · checked Sep 5, 2026
4	NewbasePartial evidence	London, United KingdomHQ checked Sep 5, 2026	501-1,000	282
	“At NewBase we provide expert and independent marketing and advertising services across all media channels globally.” Source: company website · checked Sep 5, 2026
5	Brave BisonIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	210
	“A world where complexity is the only constant demands a new breed of company.” Source: company website · checked Sep 5, 2026
6	VIOOHPartial evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	179
	“VIOOH is a leading premium global digital out of home supply side platform.” Source: company website · checked Sep 5, 2026
7	ALL Response MediaStrong evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	178
	“All Response Media is the leading performance media planning and buying agency.” Source: company website · checked Sep 5, 2026
8	BIG GroupIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	177
	“Founded in 1991, with offices in Amsterdam, Bath, Dubai and London our award-winning employee-owned company has consistently ranked as one of the UK's leading independent digital…” Source: company website · checked Sep 5, 2026
9	Expandi GroupIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	155
	“Expandi Group is a global leader in AdTech, MarTech and Managed Services.” Source: company website · checked Sep 5, 2026
10	CrimtanIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	130
	“Crimtan was established in 2009 with a clear mission: to be a trusted partner for brands navigating the complex world of programmatic advertising.” Source: company website · checked Sep 5, 2026
11	PermutivePartial evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	122
	“Permutive is the predictive collaboration platform enabling Walled Garden outcomes on the Open Internet.” Source: company website · checked Sep 5, 2026
12	AdmixerIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	99
	“Admixer is an independent adtech company that develops an ecosystem of full-stack programmatic solutions.” Source: company website · checked Sep 5, 2026
13	The Media PeopleIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	83
	“Powered by our people, our campaigns put your audience first.” Source: company website · checked Sep 5, 2026
14	Nest CommerceIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	69
	“Nest Commerce is a technology-led agency working with brands like Urban Outfitters, Hims and Damson Madder.” Source: company website · checked Sep 5, 2026
15	77agencyIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	64
	“We are an award-winning full-service digital agency, part of Jakala group with 1,800 employees across 16 countries around the world.” Source: company website · checked Sep 5, 2026
16	OCM Digital MediaIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	51-200	54
	“OCM is a leading adtech agency providing solutions to advertisers, advertising agencies and to web, mobile & video publishers.” Source: company website · checked Sep 5, 2026
17	DAXPartial evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	51
	“DAX is the largest digital audio advertising platform in the UK and one of the largest in the world.” Source: company website · checked Sep 5, 2026
18	AMS Media GroupPartial evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	50
	“From our office in London & Leeds, we seamlessly plan and buy media across all channels: digital, TV, cinema, OOH, radio, print, social and search.” Source: company website · checked Sep 5, 2026
19	Harvest DigitalPartial evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	48
	“We are a leading independent digital media agency.” Source: company website · checked Sep 5, 2026
20	Astus GroupIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	47
	“We speak to Marketing Directors across all sectors all the time and we understand their challenges and board demands: Get More ROI.” Source: company website · checked Sep 5, 2026
21	BAMBUIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	n/a	45
	“Bambu is an online marketing and advertising agency based in London, working with startup and growth brands across the UK, Europe and North America, founded by two ex-WPP…” Source: company website · checked Sep 5, 2026
22	Beautiful DigitalIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	44
	“Beautiful Digital is a full service digital marketing agency.” Source: company website · checked Sep 5, 2026
23	PEACHIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	201-500	44
	“Peach is working to radically simplify ad workflows.” Source: company website · checked Sep 5, 2026
24	UnrulyIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	501-1,000	39
	“Nexxen empowers advertisers, agencies, publishers and broadcasters around the world to utilize data and advanced TV in the ways that are most meaningful to them.” Source: company website · checked Sep 5, 2026
25	SembotIndirect evidence	London, United KingdomHQ checked Sep 5, 2026	11-50	39
	“Focus on strategy, not manually time-consuming tasks.” Source: company website · checked Sep 5, 2026

Showing 25 of 1,017 media buying platforms based in London, United Kingdom

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Media buying platforms based in London, United Kingdom at a glance

As of Sep 5, 2026

1-10Median size (employees)

LondonLargest hub · 1017 HQs

Contacts with mobile numbers

Sep 5, 2026Data refreshed

Companies by employee count

1-10

620

11-50

316

51-200

201-500

501-1,000

1,001-5,000

10001+

Email recency for this list is measured across the whole United Kingdom list rather than this city, so it is reported there. Company counts and contact totals on this page are exact for London, over 1,017 companies.

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among media buying platforms, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

Source: The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies: Companies headquartered in London, United Kingdom whose own description of what they do matches “media buying platforms”. Matching reads each company's description, not its industry code or its name.
What we exclude: Companies whose own description does not clearly place them among media buying platforms, and records with no verified work email. Companies headquartered outside London are excluded even when they keep an office there.
Match quality: In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking: Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification: Every listed company carries at least one verified work email, 4,325 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh: This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
Corrections: Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Media buying platforms by metro in the United Kingdom

Frequently asked

How many media buying platforms are there based in London, United Kingdom?

RevenueBase identified 1,017 media buying platforms headquartered in London, United Kingdom as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Publicis Media, headquartered in London, tops this list with the largest team on record.

Which city has the most media buying platforms?

London leads with 1017 headquartered companies, followed by Manchester (107) and Birmingham (60).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 4,325 verified decision-maker contacts tracked across these 1,017 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.