Company lists · Data refreshed September 2026

Top 25 Cybersecurity government staffing companies based in the United Kingdom

RevenueBase identified 860 cybersecurity government staffing companies headquartered in the United Kingdom as of September 2026 and tracks 12,900 professional contacts across them, including 3,774 with verified work emails. London is the largest hub.

This list covers cybersecurity government staffing companies 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 28, 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.

How to read this list HQ checked on every row RevenueBase Smart Search rating on every row Refreshed Sep 28, 2026 86% judged on-target in blind review
860Companies
12,900Contacts tracked
3,774Verified emails
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The 25 largest cybersecurity government staffing companies based in the United Kingdom

Ranked by team size
Top 25 of 860 cybersecurity government staffing companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to cybersecurity government staffing companies: strong evidence (its own description names it), partial (names part of it), indirect (matched on the rest of its profile rather than the description shown). Click a contact count to view that company's people.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Indirect evidenceSt Neots, United KingdomHQ checked Sep 28, 2026201-500640 contacts →

Indirect evidence

“MASS, part of the Cohort plc group, helps you realise the value of your data.”

Source: RevenueBase Database · checked Sep 28, 2026
2Partial evidenceLondon, United KingdomHQ checked Sep 28, 2026501-1,000502 contacts →

Partial evidence

“SecurityHQ, a global cybersecurity company pioneering Security Performance Engineering for stronger operational performance and resilience.”

Source: RevenueBase Database · checked Sep 28, 2026
3Indirect evidenceReading, United KingdomHQ checked Sep 28, 2026201-500303 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 28, 2026
4Indirect evidenceBillericay, United KingdomHQ checked Sep 28, 2026201-500244 contacts →

Indirect evidence

“Tangent International Integrated Talent and Delivery across Technology and Communications.”

Source: RevenueBase Database · checked Sep 28, 2026
5Indirect evidenceLondon, United KingdomHQ checked Sep 28, 2026201-500242 contacts →

Indirect evidence

“Obrela Security Industries is a global provider of cyber security services.”

Source: RevenueBase Database · checked Sep 28, 2026
6Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-200177 contacts →

Indirect evidence

“Whether you’re a business or an individual, digital threats to your precious data and assets can come in any form - external or internal.”

Source: RevenueBase Database · checked Sep 28, 2026
7Partial evidenceAlton, United KingdomHQ checked Sep 28, 2026201-500165 contacts →

Partial evidence

“Exclusive Networks is a global trusted cybersecurity specialist for digital infrastructure helping to drive the transition to a totally trusted digital future for all people and…”

Source: RevenueBase Database · checked Sep 28, 2026
8Indirect evidenceThatcham, United KingdomHQ checked Sep 28, 202651-200159 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 28, 2026
9Partial evidenceMaidenhead, United KingdomHQ checked Sep 28, 202651-200156 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
10Partial evidenceStratford Upon Avon, United KingdomHQ checked Sep 28, 202651-200138 contacts →

Partial evidence

“CCL Solutions Group is one of Europe’s leading digital forensics, digital investigation and cyber security specialists, supporting law enforcement, government agencies, military…”

Source: RevenueBase Database · checked Sep 28, 2026
11Indirect evidenceFleet, United KingdomHQ checked Sep 28, 202651-200125 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 28, 2026
12Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-200123 contacts →

Indirect evidence

“Bulletproof is now part of WorkNest Secure.”

Source: RevenueBase Database · checked Sep 28, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 28, 202651-200105 contacts →

Partial evidence

“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.”

Source: RevenueBase Database · checked Sep 28, 2026
14Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20087 contacts →

Indirect evidence

“ITC Secure is an advisory-led cyber security services company.”

Source: RevenueBase Database · checked Sep 28, 2026
15Strong evidenceBasingstoke, United KingdomHQ checked Sep 28, 202611-5085 contacts →

Strong 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 28, 2026
16Indirect evidenceSwindon, United KingdomHQ checked Sep 28, 202651-20080 contacts →

Indirect evidence

“When your business relies on security, compliance and a strong reputation for taking care of your customers, you need a partner that understands your ethos, your challenges and…”

Source: RevenueBase Database · checked Sep 28, 2026
17Indirect evidenceWaterloo, United KingdomHQ checked Sep 28, 202651-20080 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20077 contacts →

Indirect evidence

“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…”

Source: RevenueBase Database · checked Sep 28, 2026
19Indirect evidenceBristol, United KingdomHQ checked Sep 28, 202651-20075 contacts →

Indirect evidence

“SQEP provides security-cleared experts across defence, aerospace and critical infrastructure.”

Source: RevenueBase Database · checked Sep 28, 2026
20Indirect evidenceHigh Wycombe, United KingdomHQ checked Sep 28, 202651-20074 contacts →

Indirect evidence

“Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.”

Source: RevenueBase Database · checked Sep 28, 2026
21Indirect evidenceGloucester, United KingdomHQ checked Sep 28, 202651-20069 contacts →

Indirect evidence

“Modern cyber resilience demands more than isolated controls.”

Source: RevenueBase Database · checked Sep 28, 2026
22Partial evidenceLondon, United KingdomHQ checked Sep 28, 202651-20068 contacts →

Partial evidence

“With a heritage of creating National Cyber Security Centre certified products, Becrypt, a Leonardo company, is a trusted provider of endpoint cybersecurity software solutions.”

Source: RevenueBase Database · checked Sep 28, 2026
23Indirect evidenceBournemouth, United KingdomHQ checked Sep 28, 202651-20066 contacts →

Indirect evidence

“We help businesses and individuals stay protected in an increasingly complex digital world.”

Source: RevenueBase Database · checked Sep 28, 2026
24Indirect evidenceBristol, United KingdomHQ checked Sep 28, 202651-20063 contacts →

Indirect evidence

“From our offices in London, Bristol, and Manchester, Stripe OLT delivers cutting-edge cyber security and IT services to support and protect organisations in an ever-changing…”

Source: RevenueBase Database · checked Sep 28, 2026
25Indirect evidenceDoncaster, United KingdomHQ checked Sep 28, 202651-20062 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 28, 2026

Showing 25 of 860 cybersecurity government staffing companies based in the United Kingdom

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Cybersecurity government staffing companies based in the United Kingdom at a glance

As of Sep 28, 2026
29.3%Verified-email coverage
15.0Average contacts per company
1-10Median size (employees)
38.6%Largest-city concentration · London
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
523
11-50
249
51-200
66
201-500
14
501-1,000
4
1,001-5,000
3
10001+
1

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 860 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 cybersecurity government staffing companies, so some rows will be adjacent to the category rather than pure plays. The description and RevenueBase Smart Search rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase Smart Search, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United Kingdom whose own description of what they do matches “cybersecurity government staffing companies”. Matching reads each company's description, not its industry code or its name.
RevenueBase Smart Search
RevenueBase Smart Search is how this list is assembled and how each row is rated. RevenueBase's data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to a category defined in a user's own words. Each row is rated strong evidence (its own description names cybersecurity government staffing companies), partial evidence (it names part of the category) or indirect evidence (the description shown names none of it and the match rests on the rest of the company's profile). The description supporting each rating is quoted on the row.
What we exclude
Companies whose own description does not clearly place them among cybersecurity government staffing companies, 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, 3,774 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 28, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

What is RevenueBase Smart Search?

RevenueBase Smart Search is how RevenueBase decides which companies belong on this list and how strongly each one fits. Its data engine and AI assess a company's LinkedIn profile, information supplied directly by the company, its website and other publicly available information, then relate it to the category the list is about. Each row is rated strong evidence when the company's own description names cybersecurity government staffing companies, partial evidence when it names part of the category, and indirect evidence when the description shown names none of it and the match rests on the rest of the company's profile.

How many cybersecurity government staffing companies are there based in the United Kingdom?

RevenueBase identified 860 cybersecurity government staffing companies 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?

MASS, headquartered in St Neots, tops this list with the largest team on record.

Which city has the most cybersecurity government staffing companies?

London leads with 332 headquartered companies, followed by Manchester (48) and Birmingham (21).

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 3,774 verified decision-maker contacts tracked across these 860 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 28, 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.