Company lists · Data refreshed September 2026
Top 25 Security audit and compliance companies based in London, United Kingdom
RevenueBase identified 176 security audit and compliance companies headquartered in London, United Kingdom as of September 2026 and tracks 3,198 professional contacts across them, including 587 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers security audit and compliance companies 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 security audit and compliance companies based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 705 contacts → | ||||
Partial evidence “Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 2 | 242 contacts → | ||||
Partial evidence “Obrela Security Industries is a global provider of cyber security services.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 3 | 134 contacts → | ||||
Partial evidence “Turnkey Consulting brings together people, protection, and performance to help the world’s leading companies understand and optimize their risk and security landscape.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 4 | 126 contacts → | ||||
Indirect evidence “We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 5 | 123 contacts → | ||||
Indirect evidence “Bulletproof is now part of WorkNest Secure.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 6 | 97 contacts → | ||||
Partial evidence “As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 7 | 20 contacts → | ||||
Partial evidence “LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 8 | 20 contacts → | ||||
Indirect evidence “We at CF assist enterprises manage IT risks better.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 9 | 17 contacts → | ||||
Indirect evidence “We are a leading cybersecurity services organization with more than a decade of proven expertise in consulting, solution implementation and managed services.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 10 | 15 contacts → | ||||
Indirect evidence “Who We Are DataSixth delivers Cybersecurity Intelligence.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 11 | 15 contacts → | ||||
Indirect evidence “We help organisations keep their data safe, use technology responsibly, and stay on the right side of the law, without the jargon.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 12 | 15 contacts → | ||||
Partial evidence “Alltime Technologies Limited is a London based Cyber Security focused Managed Services and Consultancy provider.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 13 | 14 contacts → | ||||
Indirect evidence “Risk Crew is known for their vision, innovative thinking and facility to embrace change.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 14 | 14 contacts → | ||||
Partial evidence “Demand more from your AI & Data Security partner.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 15 | 13 contacts → | ||||
Strong evidence “Our aim is to help businesses prepare for security audits and maintain ongoing compliance efficiently and effectively.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 16 | 13 contacts → | ||||
Indirect evidence “Our mission at SOCGuardians is to empower organizations to operate confidently in a digital world by providing cutting-edge cybersecurity services.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 17 | 11 contacts → | ||||
Strong evidence “1 Cyber Valley is a PCI DSS–approved Qualified Security Assessor (QSA) and PCI PIN Assessor (QPA), delivering compliance and assurance services to clients in more than 120…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 18 | 11 contacts → | ||||
Partial evidence “At 2|SEC Consulting, we deliver an end-to-end service of cyber and information security solutions which are tailored to each client’s exact security needs.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 19 | 10 contacts → | ||||
Partial evidence “SecureTeam are a UK-based information security practice, specialising in all areas of cybersecurity.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 20 | 10 contacts → | ||||
Strong evidence “We are a UK-based Cyber Security company offering a comprehensive portfolio specialising in innovative solutions for Penetration Testing, Training, Compliance, Consulting, and…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 21 | 8 contacts → | ||||
Indirect evidence “Locked Stack is an independent cybersecurity consultancy and managed services firm headquartered in London, with a US subsidiary, operating across North America, Europe, and the…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 22 | 8 contacts → | ||||
Partial evidence “Stratia Cyber is an independent, technology agnostic company providing high quality, pragmatic cyber security consultancy and expertise, is a founder member of the NCSC Certified…” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 23 | 7 contacts → | ||||
Partial evidence “We are a global consultancy firm that specializes in Digital Risk Management and Data Privacy/Data Protection, while also ensuring robust Cyber Security measures for our clients.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 24 | 7 contacts → | ||||
Indirect evidence “Through excellent consultancy we protect clients from reputation damage, financial penalties and the operational disruption associated with data incidents and cyberattacks.” Source: RevenueBase Database · checked Sep 29, 2026Thanks. The Data Team will review it. | |||||
| 25 | 7 contacts → | ||||
Strong evidence “ISUMO leverage industry leading technologies to ensure optimum security, availability and compliance throughout your entire network.” 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: security audit and compliance companies. 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 security audit and compliance companies.
- Partial evidence
- Its own public description names part of security audit and compliance companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name security audit and compliance companies. 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 176 security audit and compliance companies based in London, United Kingdom
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Security audit and compliance companies 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 176 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 security audit and compliance companies, 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 “security audit and compliance companies”. 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 security audit and compliance companies), 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 security audit and compliance companies, 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, 587 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 security audit and compliance companies, 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 security audit and compliance companies are there based in London, United Kingdom?
RevenueBase identified 176 security audit and compliance companies 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?
COBRA, headquartered in London, tops this list with the largest team on record.
Which city in the United Kingdom has the most security audit and compliance companies?
London leads the United Kingdom with 176 headquartered companies, followed by Manchester (14) and Birmingham (12).
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 587 verified decision-maker contacts tracked across these 176 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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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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