Company lists · Data refreshed November 2026

Top 23 Managed security services companies based in the United Kingdom

RevenueBase identified 1,081 company matches for managed security services companies associated with the United Kingdom as of November 2026 and tracks 24,274 professional contacts across them, including 7,028 with verified work emails. London is the largest hub.

This list covers company matches for managed security services companies 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.

How to read this list RevenueBase SmartSearch · Exact Recorded Nov 5, 2026 How this list was built
1,081Companies
24,274Contacts tracked
7,028Verified emails
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The 23 largest managed security services companies based in the United Kingdom

Ranked by team size
Top 23 of 1,081 company matches for managed security services companies based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 5, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchAbingdon, United KingdomHQ recorded Nov 5, 20265,001-10,0005,283 contacts →

Exact match

“Sophos, a global cybersecurity leader, defends more than organizations worldwide with Sophos Fusion, the industry's first and most complete AI-native cybersecurity defense system…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
2Exact matchLondon, United KingdomHQ recorded Nov 5, 20261,001-5,000981 contacts →

Exact match

“Corps Security - experts in security with social value Built on over 165 years of experience, Corps provides specialist security services, across the UK, to ensure the safety of…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
3Exact matchLondon, United KingdomHQ recorded Nov 5, 20261,001-5,000458 contacts →

Exact match

“Ward is an award winning, privately owned business, providing bespoke risk and security solutions including protective security personnel, explosive search dogs, narcotic search…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
4Exact matchSwindon, United KingdomHQ recorded Nov 5, 2026501-1,000413 contacts →

Exact match

“SSGC is a leading innovator in the Manned Guarding industry, specialising in the application of new technology to improve the performance of its Management team, deployed staff…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
5Exact matchReading, United KingdomHQ recorded Nov 5, 2026201-500327 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
6Exact matchNewcastle Upon Tyne, United KingdomHQ recorded Nov 5, 202651-200187 contacts →

Exact match

“Sapphire delivers comprehensive cyber solutions tailored to your needs, spanning across consultancy, managed services, IT/OT and beyond.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
7Exact matchDublin 8, United KingdomHQ recorded Nov 5, 202651-200184 contacts →

Exact match

“Qualcom provides ultra secure managed IT services using a security first ethos which maximises IT uptime and ensures that data is protected and accessible 24/7.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
8Exact matchMiddx, United KingdomHQ recorded Nov 5, 2026201-500183 contacts →

Exact match

“We are able to supply a one stop security service for all types of security requirement.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
9Exact matchEnfield, United KingdomHQ recorded Nov 5, 2026501-1,000171 contacts →

Exact match

“We are GUK.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
10Exact matchSwindon, United KingdomHQ recorded Nov 5, 202651-200171 contacts →

Exact match

“One of the largest independent security companies in the UK.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
11Exact matchThatcham, United KingdomHQ recorded Nov 5, 202651-200161 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
12Exact matchMaidenhead, United KingdomHQ recorded Nov 5, 202651-200157 contacts →

Exact match

“Performanta is a global cybersecurity and data risk management company dedicated to protecting people where data matters most.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
13Exact matchPortsmouth, United KingdomHQ recorded Nov 5, 2026201-500135 contacts →

Exact match

“Vespasian Security was formed in February 2006.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
14Exact matchLondon, United KingdomHQ recorded Nov 5, 202611-50127 contacts →

Exact match

“At Secon, we empower our clients to reach their full potential by taking the stress out of cyber security.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
15Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-200123 contacts →

Exact match

“Doherty Associates is a Managed Service Provider delivering IT support, cyber security and AI enablement ‘beyond the call’.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
16Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-200105 contacts →

Exact match

“Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
17Exact matchLeeds, United KingdomHQ recorded Nov 5, 202651-200101 contacts →

Exact match

“SEP2 is an award-winning UK-based cyber security specialist service provider, powered by a dedicated team of experts available 24/7/365.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
18Exact matchGuildford, United KingdomHQ recorded Nov 5, 202651-200100 contacts →

Exact match

“ramsac provide so much more than just IT support.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
19Exact matchStourport-on-severn, United KingdomHQ recorded Nov 5, 2026201-50090 contacts →

Exact match

“CyberGuard Technologies is the security division of Wavenet.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
20Exact matchLondon, United KingdomHQ recorded Nov 5, 202651-20090 contacts →

Exact match

“Cybanetix is a leading provider of managed Cyber Security Service and hosted SIEM and breach detection services.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
21Exact matchWaterloo, United KingdomHQ recorded Nov 5, 202651-20084 contacts →

Exact match

“At Reliance Cyber, we believe in truly partnering with our customers.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase
22Exact matchOxford, United KingdomHQ recorded Nov 5, 202651-20076 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
23Exact matchFareham, United KingdomHQ recorded Nov 5, 202651-20074 contacts →

Exact match

“Established in 2015, NormCyber is a multi-award-winning cyber security specialist, on a mission to provide organisations with complete visibility and total control over cyber risk.”

Recorded in the RevenueBase company graph · Nov 5, 2026 · View company records in RevenueBase

Showing 23 of 1,081 managed security services companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 7,028 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Managed security services companies based in the United Kingdom at a glance

As of Nov 5, 2026
29.0%Verified-email coverage
22.5Average contacts per company
11-50Median size (employees)
31.0%Largest-city concentration · London
Nov 5, 2026Page data refreshed

Companies by employee count

1-10
487
11-50
362
51-200
156
201-500
46
501-1,000
8
1,001-5,000
7
5,001-10,000
2
10001+
3

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 1,081 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 “managed security services companies” 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 7,028 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.

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 “managed security services companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many managed security services companies are there based in the United Kingdom?

RevenueBase identified 1,081 company matches for managed security services companies 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?

Sophos tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most managed security services companies?

London leads with 335 company records, followed by Manchester (44) and Birmingham (29).

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 7,028 professional contacts with verified work emails tracked across these 1,081 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.

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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 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.