Company lists · Data refreshed November 2026
Top 24 Security testing firms based in the United Kingdom
RevenueBase identified 490 company matches for security testing firms associated with the United Kingdom as of November 2026 and tracks 8,107 professional contacts across them, including 2,369 with verified work emails. London is the largest hub.
This list covers company matches for security testing firms associated with the United Kingdom, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 5, 2026.
Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 24 largest security testing firms based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 782 contacts → | ||||
Exact match “Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 2 | 426 contacts → | ||||
Exact match “At Resillion, we're more than just a global leader in quality engineering, testing, and cyber security – we're your dedicated partner from the start of your project to its…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 3 | 288 contacts → | ||||
Exact match “PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 4 | 120 contacts → | ||||
Exact match “Solutions | Testing | Knowledge Helping You Protect Your Business From Cyber Attackers Your security and compliance partner, delivering trust worldwide Cognisys are your trusted…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 5 | 106 contacts → | ||||
Exact match “AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 6 | 104 contacts → | ||||
Exact match “As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 7 | 86 contacts → | ||||
Exact match “ITC Secure is an advisory-led cyber security services company.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 8 | 77 contacts → | ||||
Exact match “White Hat, part of the EPAM group, is an award-winning cyber intelligence and offensive security company that leverages an attacker’s perspective to shape innovative, proactive…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 9 | 76 contacts → | ||||
Exact match “Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 10 | 75 contacts → | ||||
Exact match “Modern cyber resilience demands more than isolated controls.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 11 | 72 contacts → | ||||
Exact match “YOU DESERVE TO BE HACKED®.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 12 | 64 contacts → | ||||
Exact match “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…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 13 | 61 contacts → | ||||
Exact match “At DigitalXRAID, we’re more than just a managed security services provider – we’re your trusted partner in safeguarding your business from cyber threats.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 14 | 59 contacts → | ||||
Exact match “Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 15 | 57 contacts → | ||||
Exact match “MDSec are a UK based consultancy with a passion for information security.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 16 | 53 contacts → | ||||
Exact match “We deliver services in Cybersecurity, Application Security and DevOps and are trusted by some of the world’s leading brands to maximise the value of their security investments and…” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 17 | 52 contacts → | ||||
Exact match “Redscan is an award-winning provider of managed security services, specialising in Managed Detection and Response, Penetration Testing and Red Teaming.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 18 | 51 contacts → | ||||
Exact match “Rootshell Security delivers human-led, AI-augmented Continuous Testing and Operational Continuous Threat Exposure Management (CTEM).” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 19 | 49 contacts → | ||||
Exact match “OnSecurity offers CREST-accredited AI Augmented Penetration Testing, all whilst harnessing technology to simplify the management and delivery of pentesting.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 20 | 46 contacts → | ||||
Exact match “CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 21 | 45 contacts → | ||||
Exact match “ERGOS is an award-winning IT Managed Service Provider.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 22 | 44 contacts → | ||||
Exact match “SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 23 | 43 contacts → | ||||
Exact match “We help organisations understand, optimise, and strengthen their cybersecurity.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
| 24 | 42 contacts → | ||||
Exact match “Secarma exists to keep the world safe.” Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase | |||||
RevenueBase SmartSearch
Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.
This list uses Exact for “security testing firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.
Showing 24 of 490 security testing firms based in the United Kingdom
See the full list, filter by size, metro and specialty, and access 2,369 tracked professional contacts with verified work emails. Direct dials are available where recorded.
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Security testing firms based in the United Kingdom at a glance
As of Nov 5, 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 490 companies.
How this list was built
The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.
- Source
- The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
- What qualifies
- Company records associated with the United Kingdom whose business descriptions match “security testing firms” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
- RevenueBase SmartSearch
- Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
- Public preview
- The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
- Match quality
- RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
- 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 displayed company carries at least one verified work email. RevenueBase tracks 2,369 professional contacts with verified work emails across the full matched dataset. 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 November 5, 2026. Lists refresh periodically as the graph is re-checked.
- Record context
- Company records and descriptions can change. Check the company's website for its current services and locations.
Security testing firms by metro
Frequently asked
What is RevenueBase SmartSearch?
RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “security testing firms”; each Exact match badge shows search membership, not an individual similarity or quality score.
How many security testing firms are there based in the United Kingdom?
RevenueBase identified 490 company matches for security testing firms associated with the United Kingdom as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.
What is the largest company on this list?
COBRA tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.
Which city has the most security testing firms?
London leads with 183 company records, followed by Manchester (27) and Cheltenham (11).
How do I get contact information for these companies?
A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 2,369 professional contacts with verified work emails tracked across these 490 companies; direct dials are available where recorded.
How current is this list?
The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 5, 2026.
Ready to reach these companies? Verified emails and direct dials for all 490 security testing firms based in the United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Security testing firms by geography
- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India
- Security testing firms based in Bangalore, India
- Security testing firms based in Hyderabad, India
- Security testing firms based in Mumbai, India
- Security testing firms based in Noida, India
- Security testing firms based in Pune, India
- Security testing firms based in Warsaw, Poland
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 SmartSearch, 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
- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India
Company intelligence · public preview
Top 24 security testing firms based in the United Kingdom
Find companies in any niche.
Describe the businesses you want in your own words. RevenueBase SmartSearch matches company descriptions by meaning.
RevenueBase records 490 matching company records for security testing firms based in the United Kingdom, with 8,107 tracked contacts and 2,369 verified work emails.
This public preview shows 24 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: November 5, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 24 security testing firms based in the United Kingdom
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 |  COBRAaudit.amazingsupport.co.ukHQ: London, United KingdomReported employees: Not recorded | London, United Kingdom | Not recorded | Exact match | 782 contacts → |
“Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 |  Resillionresillion.comHQ: London, United KingdomReported employees: 501-1,000 | London, United Kingdom | 501-1,000 | Exact match | 426 contacts → |
“At Resillion, we're more than just a global leader in quality engineering, testing, and cyber security – we're your dedicated partner from the start of your project to its…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 |  Portswiggerportswigger.netHQ: Knutsford, United KingdomReported employees: 51-200 | Knutsford, United Kingdom | 51-200 | Exact match | 288 contacts → |
“PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 |  Cognisyscognisys.co.ukHQ: Leeds, United KingdomReported employees: 51-200 | Leeds, United Kingdom | 51-200 | Exact match | 120 contacts → |
“Solutions | Testing | Knowledge Helping You Protect Your Business From Cyber Attackers Your security and compliance partner, delivering trust worldwide Cognisys are your trusted…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 |  Appcheck LTDappcheck-ng.comHQ: Leeds, United KingdomReported employees: 51-200 | Leeds, United Kingdom | 51-200 | Exact match | 106 contacts → |
“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 |  Caretower An Integrity360 Companyintegrity360.comHQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 104 contacts → |
“As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 |  ITC Secureitcsecure.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 86 contacts → |
“ITC Secure is an advisory-led cyber security services company.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 |  White HAT An Epam Companywhite-hat-cyber.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 77 contacts → |
“White Hat, part of the EPAM group, is an award-winning cyber intelligence and offensive security company that leverages an attacker’s perspective to shape innovative, proactive…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 |  Dionach By Nomiosdionach.comHQ: Oxford, United KingdomReported employees: 51-200 | Oxford, United Kingdom | 51-200 | Exact match | 76 contacts → |
“Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 |  CSA Cybercsacyber.comHQ: Gloucester, United KingdomReported employees: 51-200 | Gloucester, United Kingdom | 51-200 | Exact match | 75 contacts → |
“Modern cyber resilience demands more than isolated controls.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 |  Covertswarmcovertswarm.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 72 contacts → |
“YOU DESERVE TO BE HACKED®.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 |  Cyberlabcyberlab.co.ukHQ: Macclesfield, United KingdomReported employees: 51-200 | Macclesfield, United Kingdom | 51-200 | Exact match | 64 contacts → |
“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…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 |  Digitalxraiddigitalxraid.comHQ: Doncaster, United KingdomReported employees: 51-200 | Doncaster, United Kingdom | 51-200 | Exact match | 61 contacts → |
“At DigitalXRAID, we’re more than just a managed security services provider – we’re your trusted partner in safeguarding your business from cyber threats.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 |  Intruderintruder.ioHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 59 contacts → |
“Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 |  MDSECmdsec.co.ukHQ: Macclesfield, United KingdomReported employees: 11-50 | Macclesfield, United Kingdom | 11-50 | Exact match | 57 contacts → |
“MDSec are a UK based consultancy with a passion for information security.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 |  Riversaferiversafe.co.ukHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 53 contacts → |
“We deliver services in Cybersecurity, Application Security and DevOps and are trusted by some of the world’s leading brands to maximise the value of their security investments and…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 |  Redscan, A Kroll Businessredscan.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“Redscan is an award-winning provider of managed security services, specialising in Managed Detection and Response, Penetration Testing and Red Teaming.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 |  Rootshell Securityrootshellsecurity.netHQ: Basingstoke, United KingdomReported employees: 51-200 | Basingstoke, United Kingdom | 51-200 | Exact match | 51 contacts → |
“Rootshell Security delivers human-led, AI-augmented Continuous Testing and Operational Continuous Threat Exposure Management (CTEM).” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 |  Onsecurityonsecurity.ioHQ: Bristol, United KingdomReported employees: 51-200 | Bristol, United Kingdom | 51-200 | Exact match | 49 contacts → |
“OnSecurity offers CREST-accredited AI Augmented Penetration Testing, all whilst harnessing technology to simplify the management and delivery of pentesting.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 |  Coretech Securitycoretechsec.comHQ: Cheltenham, United KingdomReported employees: 51-200 | Cheltenham, United Kingdom | 51-200 | Exact match | 46 contacts → |
“CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 |  Ergos UKergos.ukHQ: Crawley, United KingdomReported employees: 11-50 | Crawley, United Kingdom | 11-50 | Exact match | 45 contacts → |
“ERGOS is an award-winning IT Managed Service Provider.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 |  Secforce LTDsecforce.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 44 contacts → |
“SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 |  Core To Cloudcoretocloud.co.ukHQ: Cirencester, United KingdomReported employees: 11-50 | Cirencester, United Kingdom | 11-50 | Exact match | 43 contacts → |
“We help organisations understand, optimise, and strengthen their cybersecurity.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 |  Secarma LTDsecarma.comHQ: Manchester, United KingdomReported employees: 11-50 | Manchester, United Kingdom | 11-50 | Exact match | 42 contacts → |
“Secarma exists to keep the world safe.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 24 of 490 company matches
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Security testing firms: dataset insights
November 5, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
488 records in the displayed employee bands.
2 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
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 490 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: November 5, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Security testing firms by metro
Questions about this company list
What does Exact match mean for security testing firms?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many security testing firms did RevenueBase find based in the United Kingdom?
The saved snapshot records 490 matching company records, 8,107 tracked contacts and 2,369 verified emails. The public preview displays 24 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: November 5, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
Security testing firms by geography
- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India
- Security testing firms based in Bangalore, India
- Security testing firms based in Hyderabad, India
- Security testing firms based in Mumbai, India
- Security testing firms based in Noida, India
- Security testing firms based in Pune, India
- Security testing firms based in Warsaw, Poland
Cite this list
RevenueBase Data Team. Top 24 security testing firms based in the United Kingdom. Snapshot: November 5, 2026. https://revenuebase.ai/companies/security-testing-firms/united-kingdom.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India
Company intelligence · public preview
Top 24 security testing firms based in the United Kingdom
RevenueBase records 490 matching company records for security testing firms based in the United Kingdom, with 8,107 tracked contacts and 2,369 verified work emails.
This public preview shows 24 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: November 5, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 24 security testing firms based in the United Kingdom
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 | COBRAaudit.amazingsupport.co.uk HQ: London, United KingdomReported employees: Not recorded | London, United Kingdom | Not recorded | Exact match | 782 contacts → |
“Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 | Resillionresillion.com HQ: London, United KingdomReported employees: 501-1,000 | London, United Kingdom | 501-1,000 | Exact match | 426 contacts → |
“At Resillion, we're more than just a global leader in quality engineering, testing, and cyber security – we're your dedicated partner from the start of your project to its…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 | Portswiggerportswigger.net HQ: Knutsford, United KingdomReported employees: 51-200 | Knutsford, United Kingdom | 51-200 | Exact match | 288 contacts → |
“PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 | Cognisyscognisys.co.uk HQ: Leeds, United KingdomReported employees: 51-200 | Leeds, United Kingdom | 51-200 | Exact match | 120 contacts → |
“Solutions | Testing | Knowledge Helping You Protect Your Business From Cyber Attackers Your security and compliance partner, delivering trust worldwide Cognisys are your trusted…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 | Appcheck LTDappcheck-ng.com HQ: Leeds, United KingdomReported employees: 51-200 | Leeds, United Kingdom | 51-200 | Exact match | 106 contacts → |
“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 | Caretower An Integrity360 Companyintegrity360.com HQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 104 contacts → |
“As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 | ITC Secureitcsecure.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 86 contacts → |
“ITC Secure is an advisory-led cyber security services company.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 | White HAT An Epam Companywhite-hat-cyber.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 77 contacts → |
“White Hat, part of the EPAM group, is an award-winning cyber intelligence and offensive security company that leverages an attacker’s perspective to shape innovative, proactive…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 | Dionach By Nomiosdionach.com HQ: Oxford, United KingdomReported employees: 51-200 | Oxford, United Kingdom | 51-200 | Exact match | 76 contacts → |
“Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 | CSA Cybercsacyber.com HQ: Gloucester, United KingdomReported employees: 51-200 | Gloucester, United Kingdom | 51-200 | Exact match | 75 contacts → |
“Modern cyber resilience demands more than isolated controls.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 | Covertswarmcovertswarm.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 72 contacts → |
“YOU DESERVE TO BE HACKED®.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 | Cyberlabcyberlab.co.uk HQ: Macclesfield, United KingdomReported employees: 51-200 | Macclesfield, United Kingdom | 51-200 | Exact match | 64 contacts → |
“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…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 | Digitalxraiddigitalxraid.com HQ: Doncaster, United KingdomReported employees: 51-200 | Doncaster, United Kingdom | 51-200 | Exact match | 61 contacts → |
“At DigitalXRAID, we’re more than just a managed security services provider – we’re your trusted partner in safeguarding your business from cyber threats.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 | Intruderintruder.io HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 59 contacts → |
“Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 | MDSECmdsec.co.uk HQ: Macclesfield, United KingdomReported employees: 11-50 | Macclesfield, United Kingdom | 11-50 | Exact match | 57 contacts → |
“MDSec are a UK based consultancy with a passion for information security.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 | Riversaferiversafe.co.uk HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 53 contacts → |
“We deliver services in Cybersecurity, Application Security and DevOps and are trusted by some of the world’s leading brands to maximise the value of their security investments and…” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 | Redscan, A Kroll Businessredscan.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“Redscan is an award-winning provider of managed security services, specialising in Managed Detection and Response, Penetration Testing and Red Teaming.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 | Rootshell Securityrootshellsecurity.net HQ: Basingstoke, United KingdomReported employees: 51-200 | Basingstoke, United Kingdom | 51-200 | Exact match | 51 contacts → |
“Rootshell Security delivers human-led, AI-augmented Continuous Testing and Operational Continuous Threat Exposure Management (CTEM).” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 | Onsecurityonsecurity.io HQ: Bristol, United KingdomReported employees: 51-200 | Bristol, United Kingdom | 51-200 | Exact match | 49 contacts → |
“OnSecurity offers CREST-accredited AI Augmented Penetration Testing, all whilst harnessing technology to simplify the management and delivery of pentesting.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 | Coretech Securitycoretechsec.com HQ: Cheltenham, United KingdomReported employees: 51-200 | Cheltenham, United Kingdom | 51-200 | Exact match | 46 contacts → |
“CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 | Ergos UKergos.uk HQ: Crawley, United KingdomReported employees: 11-50 | Crawley, United Kingdom | 11-50 | Exact match | 45 contacts → |
“ERGOS is an award-winning IT Managed Service Provider.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 | Secforce LTDsecforce.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 44 contacts → |
“SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 | Core To Cloudcoretocloud.co.uk HQ: Cirencester, United KingdomReported employees: 11-50 | Cirencester, United Kingdom | 11-50 | Exact match | 43 contacts → |
“We help organisations understand, optimise, and strengthen their cybersecurity.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 | Secarma LTDsecarma.com HQ: Manchester, United KingdomReported employees: 11-50 | Manchester, United Kingdom | 11-50 | Exact match | 42 contacts → |
“Secarma exists to keep the world safe.” Recorded description excerpt · November 5, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 24 of 490 company matches
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Security testing firms: dataset insights
November 5, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
488 records in the displayed employee bands.
2 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
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 490 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: November 5, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Security testing firms by metro
Questions about this company list
What does Exact match mean for security testing firms?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many security testing firms did RevenueBase find based in the United Kingdom?
The saved snapshot records 490 matching company records, 8,107 tracked contacts and 2,369 verified emails. The public preview displays 24 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: November 5, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
Security testing firms by geography
- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India
- Security testing firms based in Bangalore, India
- Security testing firms based in Hyderabad, India
- Security testing firms based in Mumbai, India
- Security testing firms based in Noida, India
- Security testing firms based in Pune, India
- Security testing firms based in Warsaw, Poland
Cite this list
RevenueBase Data Team. Top 24 security testing firms based in the United Kingdom. Snapshot: November 5, 2026. https://revenuebase.ai/companies/security-testing-firms/united-kingdom.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
More company lists
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- Security testing firms based in Melbourne, Australia
- Security testing firms based in Sydney, Australia
- Security testing firms based in Sao Paulo, Brazil
- Security testing firms based in Toronto, Canada
- Security testing firms based in Paris, France
- Security testing firms based in Ahmedabad, India