Company lists · Data refreshed September 2026
Top 25 Ott advertising platforms based in London, United Kingdom
RevenueBase identified 90 ott advertising platforms headquartered in London, United Kingdom as of September 2026 and tracks 1,476 professional contacts across them, including 586 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers ott advertising 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, 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.
The 25 largest ott advertising platforms based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 179 contacts → | ||||
Partial evidence “VIOOH is a leading premium global digital out of home supply side platform.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 2 | 122 contacts → | ||||
Partial evidence “Permutive is the predictive collaboration platform enabling Walled Garden outcomes on the Open Internet.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 3 | 99 contacts → | ||||
Indirect evidence “Admixer is an independent adtech company that develops an ecosystem of full-stack programmatic solutions.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 4 | 58 contacts → | ||||
Partial evidence “Your partner in OTT.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 5 | 54 contacts → | ||||
Partial evidence “OCM is a leading adtech agency providing solutions to advertisers, advertising agencies and to web, mobile & video publishers.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 6 | 51 contacts → | ||||
Strong evidence “DAX is the largest digital audio advertising platform in the UK and one of the largest in the world.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 7 | 39 contacts → | ||||
Indirect evidence “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: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 8 | 39 contacts → | ||||
Partial evidence “AMG is a technology company who has built one of the largest global multi-screen, multi-channel audience platforms.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 9 | 38 contacts → | ||||
Partial evidence “Our platform helps performance marketers scale social, display and retail media campaigns.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 10 | 38 contacts → | ||||
Partial evidence “We're an ad-tech company, serving the £23bn global market for audio advertising with software-as-a-service solutions for revenue optimisation, planning and scheduling.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 11 | 27 contacts → | ||||
Partial evidence “GEOMOTIVE is a marketplace that redefines DOOH advertising, fusing essential tools into a seamless ecosystem.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 12 | 25 contacts → | ||||
Partial evidence “At Voise Tech, we simplify the complexity of digital advertising through.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 13 | 24 contacts → | ||||
Indirect evidence “We offer a unique blend of cutting edge technology in combination with human connection and support.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 14 | 24 contacts → | ||||
Strong evidence “Adludio is an award-winning, AI-powered platform that delivers brand outcomes through interactive mobile advertising.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 15 | 23 contacts → | ||||
Indirect evidence “Naritive is a media owner dedicated to offering brands and companies better optimised and effective programmatic and display ad solutions.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 16 | 22 contacts → | ||||
Partial evidence “Broadlab provides a single point of access to the whole of the Addressable TV advertising landscape for agencies and their clients.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 17 | 18 contacts → | ||||
Partial evidence “Hoopla are an independent start-up online advertising network, specialising in online video, display, mobile and branded advertising solutions.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 18 | 17 contacts → | ||||
Indirect evidence “Created by GroupM in 2017, Finecast, now part of GroupM Nexus (GroupM's leading global performance group), is the group's leading addressable TV company which enables advertisers…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 19 | 17 contacts → | ||||
Indirect evidence “Ads and More Group is an international holding operating globally in programmatic marketing, built to deliver measurable growth through data, technology, and disciplined execution.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 20 | 16 contacts → | ||||
Partial evidence “Audience2Media is an Advertising Technology based company with offices in the UK and Asia, delivering data driven campaigns across all media channels, applying an innovative…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 21 | 16 contacts → | ||||
Indirect evidence “Massive is now Deltatre.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 22 | 14 contacts → | ||||
Partial evidence “Welcome to bidinfluence, your premier supply-side platform specializing in the dynamic monetization of mobile applications through top-notch programmatic video ads.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 23 | 11 contacts → | ||||
Indirect evidence “We connect brands with communities across the CTV marketplace.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 24 | 11 contacts → | ||||
Indirect evidence “We are the new media experts.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 25 | 8 contacts → | ||||
Indirect evidence “We specialise in Display, Social, Native, Video, Search, Programmatic TV, Digital Radio & Digital Out of Home, alongside Creative services, seamlessly unifying cross-channel…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: ott advertising platforms. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names ott advertising platforms.
- Partial evidence
- Its own public description names part of ott advertising platforms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name ott advertising platforms. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 90 ott advertising platforms based in London, United Kingdom
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Ott advertising platforms based in London, United Kingdom at a glance
As of Sep 29, 2026Companies by employee count
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 90 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 ott advertising platforms, 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 “ott advertising platforms”. 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 ott advertising platforms), 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 ott advertising 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 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, 586 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.
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 ott advertising platforms, 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 ott advertising platforms are there based in London, United Kingdom?
RevenueBase identified 90 ott advertising 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?
VIOOH, headquartered in London, tops this list with the largest team on record.
Which city in the United Kingdom has the most ott advertising platforms?
London leads the United Kingdom with 90 headquartered companies, followed by Manchester (5) and Birmingham (3).
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 586 verified decision-maker contacts tracked across these 90 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.
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- Ott advertising platforms based in Australia
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- Ott advertising platforms based in Canada
- Ott advertising platforms based in France
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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 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.
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