Company lists · Data refreshed September 2026

Top 25 Security consulting companies based in the United Kingdom

RevenueBase identified 1,226 security consulting companies headquartered in the United Kingdom as of September 2026 and tracks 14,177 professional contacts across them, including 3,306 with verified work emails and 965 with mobile numbers. London is the largest hub.

This list covers security consulting 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, how directly it supports the match, and when it was last checked. Data refreshed September 6, 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 HQ checked on every row Match evidence on every row Refreshed Sep 6, 2026 86% judged on-target in blind review
1,226Companies
14,177Contacts tracked
3,306Verified emails
965Mobile numbers
Explore all 1,226 companies → Free signup · no credit card · 500 free credits

The 25 largest security consulting companies based in the United Kingdom

Ranked by team size
Top 25 of 1,226 security consulting companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 6, 2026. Evidence rates how directly each company's own description names security consulting companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
SecurityhqPartial evidence
London, United KingdomHQ checked Sep 6, 2026501-1,000502

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

Source: company website · checked Sep 6, 2026
2
Ward SecurityPartial evidence
London, United KingdomHQ checked Sep 6, 20261,001-5,000419

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

Source: company website · checked Sep 6, 2026
3London, United KingdomHQ checked Sep 6, 20265,001-10,000358

“ASEL design, develop and deliver fully bespoke and integrated security solutions, seamlessly bringing together people, technology and processes to achieve results-driven outcomes.”

Source: company website · checked Sep 6, 2026
4
XalientPartial evidence
Leeds, United KingdomHQ checked Sep 6, 2026201-500260

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

Source: company website · checked Sep 6, 2026
5
ObrelaPartial evidence
London, United KingdomHQ checked Sep 6, 2026201-500242

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

Source: company website · checked Sep 6, 2026
6Woking, United KingdomHQ checked Sep 6, 2026201-500205

“Pilgrims are a global security, risk management and service support company that identifies and manages risks for clients across all sectors, including oil & gas, telecoms…”

Source: company website · checked Sep 6, 2026
7Romford, United KingdomHQ checked Sep 6, 2026201-500200

“OpenView Security Solutions is the UK’S largest privately owned independent security company and provides unique, innovative and technologically excellent solutions to meet…”

Source: company website · checked Sep 6, 2026
8Leeds, United KingdomHQ checked Sep 6, 20261,001-5,000180

“Established in 1978, Bridgegate Security is proud to be one of the UK’s largest independent security contractors.”

Source: company website · checked Sep 6, 2026
9
CyberfortPartial evidence
Thatcham, United KingdomHQ checked Sep 6, 202651-200159

“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: company website · checked Sep 6, 2026
10
PerformantaIndirect evidence
Maidenhead, United KingdomHQ checked Sep 6, 202651-200156

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

Source: company website · checked Sep 6, 2026
11
Turnkey ConsultingStrong evidence
London, United KingdomHQ checked Sep 6, 202651-200134

“Turnkey Consulting brings together people, protection, and performance to help the world’s leading companies understand and optimize their risk and security landscape.”

Source: company website · checked Sep 6, 2026
12
TrpglobalIndirect evidence
London, United KingdomHQ checked Sep 6, 202651-200126

“We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.”

Source: company website · checked Sep 6, 2026
13Watford, United KingdomHQ checked Sep 6, 202651-200116

“TSP has a reputation for providing enterprise security solutions, as well as excellent system integration standards and exceptional aftercare support, since its founding in 1988.”

Source: company website · checked Sep 6, 2026
14London, United KingdomHQ checked Sep 6, 2026201-50097

“As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.”

Source: company website · checked Sep 6, 2026
15Whiteley, United KingdomHQ checked Sep 6, 2026501-1,00087

“Croma Security Solutions Group (CSSG) began in 1970 as a family-run business in Shirley, Southampton, known as County Locksmiths.”

Source: company website · checked Sep 6, 2026
16
Amethyst Risk ManagementIndirect evidence
Basingstoke, United KingdomHQ checked Sep 6, 202611-5085

“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: company website · checked Sep 6, 2026
17
Reliance CyberIndirect evidence
Waterloo, United KingdomHQ checked Sep 6, 202651-20080

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

Source: company website · checked Sep 6, 2026
18
Peregrine Risk ManagementPartial evidence
Plymouth, United KingdomHQ checked Sep 6, 2026201-50079

“Peregrine Risk Management is a leading provider of physical security, risk consultancy, travel risk management, security intelligence, and specialist training services.”

Source: company website · checked Sep 6, 2026
19High Wycombe, United KingdomHQ checked Sep 6, 202651-20074

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

Source: company website · checked Sep 6, 2026
20
Dionach By NomiosPartial evidence
Oxford, United KingdomHQ checked Sep 6, 202651-20073

“Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.”

Source: company website · checked Sep 6, 2026
21
Black Onyx ConceptsPartial evidence
Stoke-on-trent, United KingdomHQ checked Sep 6, 202651-20071

“MITIGATING THREATS TO YOUR BUSINESS • We offer an array of security support services aligned to individual client requirements and reflective of our holistic, systematic and…”

Source: company website · checked Sep 6, 2026
22
MDSECPartial evidence
Macclesfield, United KingdomHQ checked Sep 6, 202611-5061

“MDSec are a UK based consultancy with a passion for information security.”

Source: company website · checked Sep 6, 2026
23
EvalianIndirect evidence
Southampton, United KingdomHQ checked Sep 6, 202651-20060

“Many organisations are dealing with multiple frameworks, overlapping tools, disconnected ownership, and increasing pressure from regulators, customers, and boards.”

Source: company website · checked Sep 6, 2026
24
DainttaIndirect evidence
London, United KingdomHQ checked Sep 6, 202651-20060

“We provide deep expertise with technical and business specialists to help clients secure and protect the UK.”

Source: company website · checked Sep 6, 2026
25
Assist Security GroupPartial evidence
London, United KingdomHQ checked Sep 6, 202611-5058

“Assist Security Group (ASG) helps clients build resilient, comprehensive security strategies that protect their people and assets, business continuity and reputation.”

Source: company website · checked Sep 6, 2026

Showing 25 of 1,226 security consulting companies based in the United Kingdom

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Security consulting companies based in the United Kingdom at a glance

As of Sep 6, 2026
1-10Median size (employees)
LondonLargest hub · 442 HQs
965Contacts with mobile numbers
Sep 6, 2026Data refreshed

Companies by employee count

1-10
766
11-50
316
51-200
99
201-500
26
501-1,000
10
1,001-5,000
2
5,001-10,000
2
10001+
1

Verified emails by last verification

0–30
3,045
31–60
240
61–90
4
90–180
1
180+
16

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 security consulting companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence 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 SmartSearch, 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 “security consulting companies”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among security consulting 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 an evidence 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, 3,306 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 6, 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.

Security consulting companies by metro

  • Security consulting companies in London442
  • Security consulting companies in Manchester30

Frequently asked

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

RevenueBase identified 1,226 security consulting 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?

Securityhq, headquartered in Gb, tops this list with the largest team on record.

Which city has the most security consulting companies?

London leads with 442 headquartered companies, followed by Manchester (30) and Birmingham (22).

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 3,306 verified decision-maker contacts tracked across these 1,226 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 6, 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.