Company lists · Data refreshed September 2026

Top 25 B2B media agencies based in the United Kingdom

RevenueBase identified 2,443 B2B media agencies headquartered in the United Kingdom as of September 2026 and tracks 27,276 professional contacts across them, including 7,761 with verified work emails and 2,113 with mobile numbers. London is the largest hub.

This list covers B2B media agencies headquartered in the 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 23, 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 23, 2026 86% judged on-target in blind review
2,443Companies
27,276Contacts tracked
7,761Verified emails
2,113Mobile numbers
Explore this list → Free signup · no credit card · 500 free credits

The 25 largest B2B media agencies based in the United Kingdom

Ranked by team size
Top 25 of 2,443 B2B media agencies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 23, 2026. RevenueBase Smart Search rates how each company's information relates to B2B 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 23, 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 23, 2026
2Indirect evidenceStockport, United KingdomHQ checked Sep 23, 2026501-1,0001,152 contacts →

Indirect evidence

“We’ve been delivering marketing and communications since 1961.”

Source: RevenueBase Database · checked Sep 23, 2026
3Partial evidenceLondon, United KingdomHQ checked Sep 23, 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 23, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 23, 202651-200370 contacts →

Indirect evidence

“In a world where everyone’s shouting the same thing, whisper something truly distinctive in all the right ears.”

Source: RevenueBase Database · checked Sep 23, 2026
5Partial evidenceLondon, United KingdomHQ checked Sep 23, 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 23, 2026
6Partial evidenceLondon, United KingdomHQ checked Sep 23, 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 23, 2026
7Partial evidenceLondon, United KingdomHQ checked Sep 23, 2026201-500272 contacts →

Partial evidence

“The Spafax Group is one of the world’s leading providers of media sales, entertainment curation and content marketing.”

Source: RevenueBase Database · checked Sep 23, 2026
8Indirect evidenceLeeds, United KingdomHQ checked Sep 23, 2026n/a255 contacts →

Indirect evidence

“You Grow.”

Source: RevenueBase Database · checked Sep 23, 2026
9Indirect evidenceLondon, United KingdomHQ checked Sep 23, 20261,001-5,000247 contacts →

Indirect evidence

“eg+ is now part of OCX.”

Source: RevenueBase Database · checked Sep 23, 2026
10Partial evidenceLondon, United KingdomHQ checked Sep 23, 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 23, 2026
11Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200186 contacts →

Partial evidence

“We work exclusively with B2B publishers and lead gen providers.”

Source: RevenueBase Database · checked Sep 23, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200178 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 23, 2026
13Indirect evidenceLondon, United KingdomHQ checked Sep 23, 2026201-500155 contacts →

Indirect evidence

“Expandi Group is a global leader in AdTech, MarTech and Managed Services.”

Source: RevenueBase Database · checked Sep 23, 2026
14Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200139 contacts →

Partial evidence

“Publicis Pro is the specialist B2B marketing agency within Publicis Groupe, the world's number one marketing holding group.”

Source: RevenueBase Database · checked Sep 23, 2026
15Partial evidenceFrome, United KingdomHQ checked Sep 23, 202651-200138 contacts →

Partial evidence

“The B2B marketing agency built for complex tech sales.”

Source: RevenueBase Database · checked Sep 23, 2026
16Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200136 contacts →

Partial evidence

“The Drum covers modern marketing, agency business, creativity & the future of media.”

Source: RevenueBase Database · checked Sep 23, 2026
17Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200134 contacts →

Partial evidence

“We’re a full-service marketing agency operating across Media.”

Source: RevenueBase Database · checked Sep 23, 2026
18Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200132 contacts →

Partial evidence

“We are an award-winning media planning and buying agency, helping brands cut through the noise with strategic clarity, inventive solutions, and commercial integrity.”

Source: RevenueBase Database · checked Sep 23, 2026
19Indirect evidenceLondon, United KingdomHQ checked Sep 23, 202651-200128 contacts →

Indirect evidence

“Redactive is a London-based content and publishing agency that focuses on the core professional body membership sector and has unrivalled experience in this field.”

Source: RevenueBase Database · checked Sep 23, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 23, 20265,001-10,000126 contacts →

Indirect evidence

“Zenith is the ROI Agency.”

Source: RevenueBase Database · checked Sep 23, 2026
21Partial evidenceLondon, United KingdomHQ checked Sep 23, 2026201-500126 contacts →

Partial evidence

“NRi Digital creates design-led digital content for B2B and commercial markets.”

Source: RevenueBase Database · checked Sep 23, 2026
22Strong evidenceLondon, United KingdomHQ checked Sep 23, 2026501-1,000115 contacts →

Strong evidence

“Tarsus Group delivers B2B events across the globe along with digital media & industry-focussed publications.”

Source: RevenueBase Database · checked Sep 23, 2026
23Partial evidenceLondon, United KingdomHQ checked Sep 23, 202651-200111 contacts →

Partial evidence

“We’re The Kite Factory, the independent media agency built on Values and Velocity.”

Source: RevenueBase Database · checked Sep 23, 2026
24Indirect evidenceLondon, United KingdomHQ checked Sep 23, 2026201-500107 contacts →

Indirect evidence

“From pigeons to platforms, from news agency to integrated communications services, our story is one of constant reinvention.”

Source: RevenueBase Database · checked Sep 23, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 23, 2026501-1,000103 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 23, 2026

Showing 25 of 2,443 B2B media agencies based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 7,761 reachable decision-makers.

Free signup · no credit card

View the full list →

B2B media agencies based in the United Kingdom at a glance

As of Sep 23, 2026
28.5%Verified-email coverage
7.7%Mobile-number coverage
11.2Average contacts per company
1-10Median size (employees)
34.1%Largest-city concentration · London
Sep 23, 2026Page data refreshed

Companies by employee count

1-10
1,745
11-50
549
51-200
99
201-500
21
501-1,000
12
1,001-5,000
4
5,001-10,000
4

Freshness & accuracy

How recently the business emails were verified and the company information checked

Email last verified

Median 25.0d

Company record updated

Median 88.0d

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 B2B 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 the United Kingdom whose own description of what they do matches “B2B 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 B2B 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 B2B media agencies, and records with no verified work email. Companies headquartered outside United Kingdom 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, 7,761 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 23, 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.

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 B2B 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 B2B media agencies are there based in the United Kingdom?

RevenueBase identified 2,443 B2B media agencies headquartered in the 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?

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

Which city has the most B2B media agencies?

London leads with 833 headquartered companies, followed by Manchester (75) and Birmingham (54).

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 7,761 verified decision-maker contacts tracked across these 2,443 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 23, 2026.

Ready to reach these companies? Verified emails and direct dials for all 2,443 B2B media agencies based in the 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.