Company lists · Data refreshed September 2026
Top 25 Security consultancy firms based in London, United Kingdom
RevenueBase identified 528 security consultancy firms headquartered in London, United Kingdom as of September 2026 and tracks 7,440 professional contacts across them, including 1,192 with verified work emails. London is the largest hub.
This list covers security consultancy firms 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 21, 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 consultancy firms based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 419 contacts → | ||||
Partial evidence “Ward is an award winning, privately owned business, providing bespoke risk and security solutions including protective security personnel, explosive search dogs, narcotic search…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 351 contacts → | ||||
Strong evidence “S-RM is a global intelligence and cyber security consultancy.” Source: RevenueBase Database · checked Sep 21, 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 21, 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 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 116 contacts → | ||||
Strong evidence “SSR® Personnel is the largest recruitment consultancy & executive search practice dedicated to the security, fire, health and safety sectors.” Source: RevenueBase Database · checked Sep 21, 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 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 85 contacts → | ||||
Indirect evidence “We understand that fire safety can be a daunting prospect.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 78 contacts → | ||||
Partial evidence “Principle One provides Systems Engineering, Architecture and Business Consulting services within the Law Enforcement, National Security, Health and wider public sector.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 62 contacts → | ||||
Partial evidence “Cyro Cyber are your cyber security Guardians.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 60 contacts → | ||||
Indirect evidence “We provide deep expertise with technical and business specialists to help clients secure and protect the UK.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 58 contacts → | ||||
Partial evidence “Black Diamond Security - Safeguarding Your World.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 51 contacts → | ||||
Partial evidence “Established in Custom Intelligent Security is a technology driven ISO27001 & NSi Gold Accredited independent electronic security specialist with a proven track record of…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 49 contacts → | ||||
Partial evidence “GSA Global helps organisations, families and individuals respond to serious, complex and emerging security risks.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 48 contacts → | ||||
Indirect evidence “In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 44 contacts → | ||||
Partial evidence “CornerStone is an award winning, independent, security and digital building consulting firm with headquarters in the UK.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 39 contacts → | ||||
Partial evidence “Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 39 contacts → | ||||
Partial evidence “SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 37 contacts → | ||||
Indirect evidence “Audere Group is a London-headquartered holistic risk advisory company founded in 2014.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 34 contacts → | ||||
Partial evidence “Skylark is a bespoke security service provider based in London.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 33 contacts → | ||||
Indirect evidence “Othrys is a global strategic and risk advisory firm founded in 2016.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 32 contacts → | ||||
Partial evidence “As an independent fire safety consultancy, we thrive for highest quality of advice whilst ensuring life safety is always our priority.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 30 contacts → | ||||
Partial evidence “Capstar provides technology-enabled threat, risk and security services to private and corporate clients.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 29 contacts → | ||||
Strong evidence “Defence and security services consultancy.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 29 contacts → | ||||
Indirect evidence “Cyber Rescue is a leading specialist in helping Boardroom Executives to measure, monitor and mitigate potential harm from cyber-attacks.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 28 contacts → | ||||
Partial evidence “Priavo Security Group is an established provider of comprehensive security risk management, dedicated to safeguarding individuals, information, assets, and reputation through…” Source: RevenueBase Database · checked Sep 21, 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 consultancy firms. 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 consultancy firms.
- Partial evidence
- Its own public description names part of security consultancy firms, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name security consultancy firms. 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 528 security consultancy firms based in London, United Kingdom
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Security consultancy firms based in London, United Kingdom at a glance
As of Sep 21, 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 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 security consultancy firms, 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 consultancy firms”. 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 consultancy firms), 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 consultancy firms, 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, 1,192 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 21, 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.
Security consultancy firms by metro in the United Kingdom
- Security consultancy firms in London528
- Security consultancy firms in Manchester30
- Security consultancy firms in Birmingham25
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 consultancy firms, 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 consultancy firms are there based in London, United Kingdom?
RevenueBase identified 528 security consultancy firms 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?
Ward Security, headquartered in London, tops this list with the largest team on record.
Which city has the most security consultancy firms?
London leads with 528 headquartered companies, followed by Manchester (30) and Birmingham (25).
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 1,192 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 21, 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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