Company lists · Data refreshed September 2026
Top 25 Outsourced ciso services based in the United Kingdom
RevenueBase identified 782 outsourced ciso services headquartered in the United Kingdom as of September 2026 and tracks 7,745 professional contacts across them, including 3,118 with verified work emails. London is the largest hub.
This list covers outsourced ciso services 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 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 outsourced ciso services based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 303 contacts → | ||||
Indirect evidence “Bridewell is the trusted cyber security partner for organisations operating within Critical National Infrastructure (CNI), as well as companies who want the highest standard of…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 260 contacts → | ||||
Indirect evidence “We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 3 | 190 contacts → | ||||
Indirect evidence “Intragen is a cyber security business focused on managed Identity solutions and services.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 168 contacts → | ||||
Indirect evidence “Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 159 contacts → | ||||
Indirect evidence “At Cyberfort we are passionate about the cyber security services we deliver for our customers which keeps their people, data, systems and technology infrastructure secure…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 6 | 156 contacts → | ||||
Indirect evidence “Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 125 contacts → | ||||
Indirect evidence “KHIPU Networks is an award winning international Cyber Security Company delivering a wide range of network, wireless and security solutions, technologies and services across…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 123 contacts → | ||||
Indirect evidence “Bulletproof is now part of WorkNest Secure.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 97 contacts → | ||||
Indirect 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. | |||||
| 10 | 93 contacts → | ||||
Indirect evidence “ramsac provide so much more than just IT support.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 86 contacts → | ||||
Indirect evidence “CyberGuard Technologies is the security division of Wavenet.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 12 | 85 contacts → | ||||
Indirect evidence “Amethyst Risk Management is a leading cybersecurity consultancy supplying expert services and support to the UK Government, Defence, Operators of Essential Services, and the…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 80 contacts → | ||||
Indirect evidence “At Reliance Cyber, we believe in truly partnering with our customers.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 14 | 79 contacts → | ||||
Indirect evidence “Virtual IT are a leading provider of cyber-secure cloud and managed IT services in the UK, entrusted by over 700 businesses and schools as their end-to-end technology partner.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 74 contacts → | ||||
Indirect evidence “Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 73 contacts → | ||||
Indirect evidence “Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 73 contacts → | ||||
Indirect evidence “Bluecube - An Ekco Company Our mission is simple.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 62 contacts → | ||||
Indirect evidence “At DigitalXRAID, we’re more than just a managed security services provider – we’re your trusted partner in safeguarding your business from cyber threats.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 60 contacts → | ||||
Indirect evidence “Many organisations are dealing with multiple frameworks, overlapping tools, disconnected ownership, and increasing pressure from regulators, customers, and boards.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 20 | 57 contacts → | ||||
Indirect evidence “CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 52 contacts → | ||||
Indirect evidence “At Hexegic we are not just passionate about protecting data through our Cyber services we are passionate about helping companies release the potential of the data they hold…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 22 | 49 contacts → | ||||
Indirect evidence “PureCyber is an award-winning, expert Cyber Security Consultancy.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 45 contacts → | ||||
Indirect evidence “Established in 2004 (acquired by Gamma in 2023), Satisnet, a Gamma company is a pedigree-proven cyber security services and solutions specialist with a fully UK-based 24x7x365 SOC.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 39 contacts → | ||||
Indirect evidence “We help organisations understand, optimise, and strengthen their cybersecurity.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 39 contacts → | ||||
Indirect evidence “For over 20 years, we’ve helped businesses stay productive, secure and resilient through reliable IT support, modern cloud solutions and cyber security services designed for…” 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: outsourced ciso services. 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 outsourced ciso services.
- Partial evidence
- Its own public description names part of outsourced ciso services, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name outsourced ciso services. 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 782 outsourced ciso services based in the United Kingdom
See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 3,118 reachable decision-makers.
Free signup · no credit card
Outsourced ciso services based in the United Kingdom at a glance
As of Sep 21, 2026Companies by employee count
Email recency for this list is measured worldwide rather than for United Kingdom, so it is reported there. Company counts and contact totals on this page are exact for United Kingdom, over 782 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 outsourced ciso services, 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 “outsourced ciso services”. 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 outsourced ciso services), 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 outsourced ciso services, 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, 3,118 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.
Outsourced ciso services by metro
- Outsourced ciso services in London265
- Outsourced ciso services in Manchester30
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 outsourced ciso services, 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 outsourced ciso services are there based in the United Kingdom?
RevenueBase identified 782 outsourced ciso services 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?
Bridewell, headquartered in Reading, tops this list with the largest team on record.
Which city has the most outsourced ciso services?
London leads with 265 headquartered companies, followed by Manchester (30) and Birmingham (17).
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 3,118 verified decision-maker contacts tracked across these 782 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.
Ready to reach these companies? Verified emails and direct dials for all 782 outsourced ciso services based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Outsourced ciso services by geography
- Outsourced ciso services based in Brisbane, Australia
- Outsourced ciso services based in Melbourne, Australia
- Outsourced ciso services based in Sydney, Australia
- Outsourced ciso services based in Calgary, Canada
- Outsourced ciso services based in Montreal, Canada
- Outsourced ciso services based in Ottawa, Canada
- Outsourced ciso services based in Toronto, Canada
- Outsourced ciso services based in Ahmedabad, India
- Outsourced ciso services based in Bangalore, India
- Outsourced ciso services based in Bengaluru, India
- Outsourced ciso services based in Chennai, India
- Outsourced ciso services based in Hyderabad, India
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Outsourced ciso services based in Brisbane, Australia
- Outsourced ciso services based in Melbourne, Australia
- Outsourced ciso services based in Sydney, Australia
- Outsourced ciso services based in Calgary, Canada
- Outsourced ciso services based in Montreal, Canada
- Outsourced ciso services based in Ottawa, Canada