Company lists · Data refreshed September 2026

Top 25 Cyber security consultancies based in the United Kingdom

RevenueBase identified 2,283 cyber security consultancies headquartered in the United Kingdom as of September 2026 and tracks 31,728 professional contacts across them, including 11,712 with verified work emails. London is the largest hub.

This list covers cyber security consultancies 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 14, 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 14, 2026 86% judged on-target in blind review
2,283Companies
31,728Contacts tracked
11,712Verified emails
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The 25 largest cyber security consultancies based in the United Kingdom

Ranked by team size
Top 25 of 2,283 cyber security consultancies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 14, 2026. RevenueBase Smart Search rates how each company's information relates to cyber security consultancies: 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 evidenceAbingdon, United KingdomHQ checked Sep 14, 20265,001-10,0004,925 contacts →

Indirect evidence

“Sophos is a cybersecurity leader defending organizations globally with an AI-driven platform and expert-led services.”

Source: RevenueBase Database · checked Sep 14, 2026
2Strong evidenceStaines-upon-thames, United KingdomHQ checked Sep 14, 2026201-500764 contacts →

Strong evidence

“MTI provides award-winning, end-to-end technology solutions and services in cyber security and data centre for over 35 years.”

Source: RevenueBase Database · checked Sep 14, 2026
3Strong evidenceLondon, United KingdomHQ checked Sep 14, 2026n/a705 contacts →

Strong evidence

“Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.”

Source: RevenueBase Database · checked Sep 14, 2026
4Partial evidenceLondon, United KingdomHQ checked Sep 14, 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 14, 2026
5Strong evidenceReading, United KingdomHQ checked Sep 14, 2026201-500366 contacts →

Strong evidence

“FSP is a leading consultancy specialising in Data and AI, Cyber Security, Enterprise Cloud and Change Delivery, providing advisory led enterprise transformation delivered through…”

Source: RevenueBase Database · checked Sep 14, 2026
6Indirect evidenceNottingham, United KingdomHQ checked Sep 14, 2026201-500364 contacts →

Indirect evidence

“Littlefish is a multi-award-winning Managed IT Services Provider that continues to grow consistently and significantly through tangibly delivering on our promises of enhanced user…”

Source: RevenueBase Database · checked Sep 14, 2026
7Strong evidenceLondon, United KingdomHQ checked Sep 14, 2026201-500351 contacts →

Strong evidence

“S-RM is a global intelligence and cyber security consultancy.”

Source: RevenueBase Database · checked Sep 14, 2026
8Indirect evidenceWest End, United KingdomHQ checked Sep 14, 2026201-500326 contacts →

Indirect evidence

“As our name suggests, our customers rely on us in providing suitable technology inputs to support their business goals.”

Source: RevenueBase Database · checked Sep 14, 2026
9Strong evidenceReading, United KingdomHQ checked Sep 14, 2026201-500303 contacts →

Strong 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 14, 2026
10Partial evidenceEdinburgh, United KingdomHQ checked Sep 14, 2026201-500297 contacts →

Partial evidence

“At Quorum Cyber, we're on a mission to help good people win.”

Source: RevenueBase Database · checked Sep 14, 2026
11Partial evidenceLeeds, United KingdomHQ checked Sep 14, 2026201-500260 contacts →

Partial evidence

“We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.”

Source: RevenueBase Database · checked Sep 14, 2026
12Indirect evidenceGreenham, United KingdomHQ checked Sep 14, 2026201-500243 contacts →

Indirect evidence

“Roc Technologies delivers transformational IT solutions to public and private sector organisations across the UK.”

Source: RevenueBase Database · checked Sep 14, 2026
13Strong evidenceLondon, United KingdomHQ checked Sep 14, 2026201-500242 contacts →

Strong evidence

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

Source: RevenueBase Database · checked Sep 14, 2026
14Indirect evidenceDurham, United KingdomHQ checked Sep 14, 2026201-500215 contacts →

Indirect evidence

“We are an IT business with a difference.”

Source: RevenueBase Database · checked Sep 14, 2026
15Strong evidenceLondon, United KingdomHQ checked Sep 14, 2026201-500190 contacts →

Strong evidence

“Intragen is a cyber security business focused on managed Identity solutions and services.”

Source: RevenueBase Database · checked Sep 14, 2026
16Indirect evidenceLondon, United KingdomHQ checked Sep 14, 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 14, 2026
17Partial evidenceLondon, United KingdomHQ checked Sep 14, 2026n/a171 contacts →

Partial evidence

Security Blue Team is now Centri.”

Source: RevenueBase Database · checked Sep 14, 2026
18Partial evidenceNewcastle Upon Tyne, United KingdomHQ checked Sep 14, 202651-200168 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 14, 2026
19Indirect evidenceAlton, United KingdomHQ checked Sep 14, 2026201-500165 contacts →

Indirect 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 14, 2026
20Indirect evidenceManchester, United KingdomHQ checked Sep 14, 2026201-500165 contacts →

Indirect evidence

“FourNet transforms the customer and citizen services people rely on every day.”

Source: RevenueBase Database · checked Sep 14, 2026
21Strong evidenceThatcham, United KingdomHQ checked Sep 14, 202651-200159 contacts →

Strong 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 14, 2026
22Indirect evidenceMaidenhead, United KingdomHQ checked Sep 14, 202651-200156 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 14, 2026
23Partial evidenceCheltenham, United KingdomHQ checked Sep 14, 202651-200156 contacts →

Partial evidence

“CDS Defence & Security is a technical consultancy working to enhance operational effectiveness and bring about behavioural change in the defence sector.”

Source: RevenueBase Database · checked Sep 14, 2026
24Strong evidenceBradley Stoke, United KingdomHQ checked Sep 14, 2026201-500143 contacts →

Strong evidence

“Logiq is a UK-based cyber security consultancy and secure managed services provider supporting defence, government, and critical national infrastructure (CNI) organisations where…”

Source: RevenueBase Database · checked Sep 14, 2026
25Strong evidenceStratford Upon Avon, United KingdomHQ checked Sep 14, 202651-200138 contacts →

Strong 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 14, 2026

Showing 25 of 2,283 cyber security consultancies based in the United Kingdom

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Cyber security consultancies based in the United Kingdom at a glance

As of Sep 14, 2026
36.9%Verified-email coverage
13.9Average contacts per company
1-10Median size (employees)
36.8%Largest-city concentration · London
Sep 14, 2026Page data refreshed

Companies by employee count

1-10
1,472
11-50
601
51-200
146
201-500
41
501-1,000
6
1,001-5,000
9
5,001-10,000
2
10001+
2

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 2,283 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 cyber security consultancies, 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 “cyber security consultancies”. 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 cyber security consultancies), 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 cyber security consultancies, 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, 11,712 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 14, 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 cyber security consultancies, 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 cyber security consultancies are there based in the United Kingdom?

RevenueBase identified 2,283 cyber security consultancies 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?

Sophos, headquartered in Abingdon, tops this list with the largest team on record.

Which city has the most cyber security consultancies?

London leads with 841 headquartered companies, followed by Manchester (76) and Birmingham (40).

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 11,712 verified decision-maker contacts tracked across these 2,283 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 14, 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.