Company lists · Data refreshed September 2026

Top 25 Omnichannel media agencies based in London, United Kingdom

RevenueBase identified 528 omnichannel media agencies headquartered in London, United Kingdom as of September 2026 and tracks 38,793 professional contacts across them, including 8,944 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers omnichannel media agencies 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 29, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase Smart Search, 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 RevenueBase Smart Search rating on every row Refreshed Sep 29, 2026 86% judged on-target in blind review
528Companies
38,793Contacts tracked
8,944Verified emails
Explore this list → Free signup · no credit card · 500 free credits

The 25 largest omnichannel media agencies based in London, United Kingdom

Ranked by team size
Top 25 of 528 omnichannel media agencies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to omnichannel media agencies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Partial evidenceLondon, United KingdomHQ checked Sep 29, 202610001+6,901 contacts →

Partial evidence

“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: RevenueBase Database · checked Sep 29, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20265,001-10,0004,133 contacts →

Indirect evidence

“Zenith is the ROI Agency.”

Source: RevenueBase Database · checked Sep 29, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 29, 20265,001-10,0002,366 contacts →

Partial evidence

“iProspect, a dentsu company, is a leading global digital-first media agency.”

Source: RevenueBase Database · checked Sep 29, 2026
4Partial evidenceLondon, United KingdomHQ checked Sep 29, 20265,001-10,0002,182 contacts →

Partial evidence

“Carat is the world’s first media agency and is privileged to work with some of today’s most storied and innovative brands.”

Source: RevenueBase Database · checked Sep 29, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20265,001-10,000941 contacts →

Indirect evidence

“Welcome to dentsu X.”

Source: RevenueBase Database · checked Sep 29, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261,001-5,000925 contacts →

Indirect evidence

“A global, fully integrated agency with AI at its heart.”

Source: RevenueBase Database · checked Sep 29, 2026
7Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026501-1,000643 contacts →

Partial evidence

“We're an independent global media, creative, and data agency helping our clients make their next best move.”

Source: RevenueBase Database · checked Sep 29, 2026
8Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261,001-5,000544 contacts →

Indirect evidence

“Happy to see you came here to learn a little more about us!”

Source: RevenueBase Database · checked Sep 29, 2026
9Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500527 contacts →

Partial evidence

“MG OMD, part of Omnicom Media, brings innovation, insight and creativity to the world of media.”

Source: RevenueBase Database · checked Sep 29, 2026
10Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500457 contacts →

Partial evidence

“We are a Global digital media agency specializing in taking a human approach to connecting brands with people across all channels.”

Source: RevenueBase Database · checked Sep 29, 2026
11Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500455 contacts →

Indirect evidence

“We’re the original pioneers in connected commerce marketing.”

Source: RevenueBase Database · checked Sep 29, 2026
12Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500439 contacts →

Indirect evidence

“TMW, part of Accenture Song, is an integrated creative agency.”

Source: RevenueBase Database · checked Sep 29, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026501-1,000416 contacts →

Partial evidence

“EssenceMediacom is WPP Media's newest and largest agency, committed to delivering breakthroughs for brands in the New Communications Economy.”

Source: RevenueBase Database · checked Sep 29, 2026
14Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500295 contacts →

Partial evidence

“the7stars is the UK’s largest independent media agency, offering the best people, the best service and the best creative media campaigns.”

Source: RevenueBase Database · checked Sep 29, 2026
15Partial evidenceLondon, United KingdomHQ checked Sep 29, 2026501-1,000282 contacts →

Partial evidence

“At NewBase we provide expert and independent marketing and advertising services across all media channels globally.”

Source: RevenueBase Database · checked Sep 29, 2026
16Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500269 contacts →

Indirect evidence

“Greenpark is a global, award-winning digital agency.”

Source: RevenueBase Database · checked Sep 29, 2026
17Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261,001-5,000247 contacts →

Indirect evidence

“eg+ is now part of OCX.”

Source: RevenueBase Database · checked Sep 29, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500210 contacts →

Indirect evidence

“A world where complexity is the only constant demands a new breed of company.”

Source: RevenueBase Database · checked Sep 29, 2026
19Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-200195 contacts →

Partial evidence

“Medialab is the UK’s leading independent media agency, Campaign's 2025 & 2024 Independent Media Agency of the Year and Media Week's Independent Media Agency of the Year 2025…”

Source: RevenueBase Database · checked Sep 29, 2026
20Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-200180 contacts →

Partial evidence

“Cedar is a specialist agency dedicated to helping brands unlock the full value of their audiences, platforms and partnerships through expertly crafted media networks and creative…”

Source: RevenueBase Database · checked Sep 29, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 29, 202651-200178 contacts →

Partial evidence

“All Response Media is the leading performance media planning and buying agency.”

Source: RevenueBase Database · checked Sep 29, 2026
22Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500150 contacts →

Indirect evidence

“At krow Group, our ideas are designed to make a genuine difference, building your brand and making it easier to buy by capturing and converting people’s attention.”

Source: RevenueBase Database · checked Sep 29, 2026
23Indirect evidenceLondon, United KingdomHQ checked Sep 29, 202651-200134 contacts →

Indirect evidence

Source: RevenueBase Database · checked Sep 29, 2026
24Indirect evidenceLondon, United KingdomHQ checked Sep 29, 2026201-500132 contacts →

Indirect evidence

“Metia is a global marketing agency with offices in London, Seattle, Austin and Singapore.”

Source: RevenueBase Database · checked Sep 29, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 29, 20261,001-5,000117 contacts →

Indirect evidence

“We’re MSQ.”

Source: RevenueBase Database · checked Sep 29, 2026

Showing 25 of 528 omnichannel media agencies based in London, United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 8,944 reachable decision-makers.

Free signup · no credit card

View the full list →

Omnichannel media agencies based in London, United Kingdom at a glance

As of Sep 29, 2026
23.1%Verified-email coverage
73.5Average contacts per company
11-50Median size (employees)
Sep 29, 2026Page data refreshed

Companies by employee count

1-10
254
11-50
163
51-200
52
201-500
26
501-1,000
15
1,001-5,000
9
5,001-10,000
7
10001+
1

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 528 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 omnichannel media agencies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search 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 Smart Search, 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 “omnichannel media agencies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names omnichannel media agencies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among omnichannel media agencies, 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 its RevenueBase Smart Search 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, 8,944 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 29, 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.

Omnichannel media agencies by metro in the United Kingdom

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names omnichannel media agencies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many omnichannel media agencies are there based in London, United Kingdom?

RevenueBase identified 528 omnichannel media agencies 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 in the United Kingdom has the most omnichannel media agencies?

London leads the United Kingdom with 528 headquartered companies, followed by Manchester (49) and Leeds (39).

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 8,944 verified decision-maker contacts tracked across these 528 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 29, 2026.

Ready to reach these companies? Verified emails and direct dials for all 528 omnichannel media agencies based in London, United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

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 Smart Search, 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.