Company lists · Data refreshed September 2026

Top 25 Application security consulting services based in the United Kingdom

RevenueBase identified 288 application security consulting services headquartered in the United Kingdom as of September 2026 and tracks 2,769 professional contacts across them, including 659 with verified work emails. London is the largest hub.

This list covers application security consulting services 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 21, 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 21, 2026 86% judged on-target in blind review
288Companies
2,769Contacts tracked
659Verified emails
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The 25 largest application security consulting services based in the United Kingdom

Ranked by team size
Top 25 of 288 application security consulting services based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 21, 2026. RevenueBase Smart Search rates how each company's information relates to application security consulting services: 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
1Strong evidenceLondon, United KingdomHQ checked Sep 21, 202651-200134 contacts →

Strong evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
2Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202651-200126 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
3Partial evidenceLeeds, United KingdomHQ checked Sep 21, 202651-20099 contacts →

Partial evidence

“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.”

Source: RevenueBase Database · checked Sep 21, 2026
4Partial evidenceLondon, United KingdomHQ checked Sep 21, 2026201-50097 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceMacclesfield, United KingdomHQ checked Sep 21, 202611-5061 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
6Partial evidenceAlderley Edge, United KingdomHQ checked Sep 21, 202651-20057 contacts →

Partial evidence

“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…”

Source: RevenueBase Database · checked Sep 21, 2026
7Strong evidenceLondon, United KingdomHQ checked Sep 21, 202611-5057 contacts →

Strong evidence

“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…”

Source: RevenueBase Database · checked Sep 21, 2026
8Indirect evidenceManchester, United KingdomHQ checked Sep 21, 202611-5036 contacts →

Indirect evidence

“Secarma exists to keep the world safe.”

Source: RevenueBase Database · checked Sep 21, 2026
9Partial evidenceBirmingham, United KingdomHQ checked Sep 21, 202611-5032 contacts →

Partial evidence

“Aristi is a specialist provider of cyber security services with over 17 years of experience.”

Source: RevenueBase Database · checked Sep 21, 2026
10Partial evidenceSolihull, United KingdomHQ checked Sep 21, 202611-5031 contacts →

Partial evidence

“SPECIALISTS IN IT SECURITY AND COMPLIANCE Our goal is to help customers define, develop and implement information security and compliance services, no matter what stage of the…”

Source: RevenueBase Database · checked Sep 21, 2026
11Partial evidenceAltrincham, United KingdomHQ checked Sep 21, 202611-5026 contacts →

Partial evidence

“Based in Manchester UK, we are an independent Cyber Security Consultancy providing Security services across a wide range of markets, from multi-national Corporate Organisations…”

Source: RevenueBase Database · checked Sep 21, 2026
12Partial evidenceCambridge, United KingdomHQ checked Sep 21, 202611-5021 contacts →

Partial evidence

“Chaleit is a cyber security management consultancy that aligns business context with real-world capability to solve complex risks.”

Source: RevenueBase Database · checked Sep 21, 2026
13Partial evidenceLondon, United KingdomHQ checked Sep 21, 202611-5020 contacts →

Partial evidence

“LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…”

Source: RevenueBase Database · checked Sep 21, 2026
14Partial evidenceLondon, United KingdomHQ checked Sep 21, 202611-5020 contacts →

Partial evidence

“Formed in 2018, NGS (UK) Ltd are independent, Next Generation Security trusted advisors, providing all-encompassing solutions from the perimeter to the endpoint.”

Source: RevenueBase Database · checked Sep 21, 2026
15Partial evidenceTunbridge Wells, United KingdomHQ checked Sep 21, 202611-5019 contacts →

Partial evidence

“Razorthorn Security is a specialist cybersecurity consultancy founded in 2007, with nearly two decades of experience helping organisations protect their data, their systems and…”

Source: RevenueBase Database · checked Sep 21, 2026
16Indirect evidenceLeeds, United KingdomHQ checked Sep 21, 202611-5019 contacts →

Indirect evidence

“Halo I.S is not just another cybersecurity organization based in the UK; we're a testament to evolution and client-centric innovation.”

Source: RevenueBase Database · checked Sep 21, 2026
17Partial evidenceEdinburgh, United KingdomHQ checked Sep 21, 202611-5017 contacts →

Partial evidence

“We are a cyber security consultancy that specialises in security solution architecture, engineering, implementation and operational support.”

Source: RevenueBase Database · checked Sep 21, 2026
18Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-5015 contacts →

Indirect evidence

“is an ISO 9001:2015 and ISO/IEC 27001:2022 certified, DPIIT-recognized cybersecurity company delivering structured External Vulnerability Assessment & Penetration Testing (VAPT)…”

Source: RevenueBase Database · checked Sep 21, 2026
19Partial evidenceBelfast, United KingdomHQ checked Sep 21, 202611-5012 contacts →

Partial evidence

“Cyber Guarded is a vendor independent business which provides Cyber Security auditing and testing services.”

Source: RevenueBase Database · checked Sep 21, 2026
20Indirect evidenceBath, United KingdomHQ checked Sep 21, 202611-5011 contacts →

Indirect evidence

“At Mobius Binary we care about your reputation and the loss that could result from violating your digital boundaries.”

Source: RevenueBase Database · checked Sep 21, 2026
21Partial evidenceSouthend-on-sea, United KingdomHQ checked Sep 21, 202611-5011 contacts →

Partial evidence

“Cyber Trust | Your security team around your existing IT Cyber Trust is a UK‑based cyber security firm that works alongside your existing IT team or technology provider.”

Source: RevenueBase Database · checked Sep 21, 2026
22Partial evidenceMaidenhead, United KingdomHQ checked Sep 21, 20261-1010 contacts →

Partial evidence

“After being frustrated in the way that Cyber Security services were being delivered to organisations, Cyberhash was founded with a fresh approach to Cyber Security - keeping you…”

Source: RevenueBase Database · checked Sep 21, 2026
23Indirect evidenceManchester, United KingdomHQ checked Sep 21, 202611-508 contacts →

Indirect evidence

“Cytix is the AppSec layer that focuses testing where it matters.”

Source: RevenueBase Database · checked Sep 21, 2026
24Partial evidenceLondon, United KingdomHQ checked Sep 21, 202611-508 contacts →

Partial evidence

“Stratia Cyber is an independent, technology agnostic company providing high quality, pragmatic cyber security consultancy and expertise, is a founder member of the NCSC Certified…”

Source: RevenueBase Database · checked Sep 21, 2026
25Indirect evidenceLondon, United KingdomHQ checked Sep 21, 202611-507 contacts →

Indirect evidence

“Through excellent consultancy we protect clients from reputation damage, financial penalties and the operational disruption associated with data incidents and cyberattacks.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 288 application security consulting services based in the United Kingdom

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Application security consulting services based in the United Kingdom at a glance

As of Sep 21, 2026
23.8%Verified-email coverage
9.6Average contacts per company
1-10Median size (employees)
38.2%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
205
11-50
63
51-200
12
201-500
5
501-1,000
1
5,001-10,000
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 288 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 application security consulting services, 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 “application security consulting services”. 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 application security consulting services), 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 application security consulting services, 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, 659 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 21, 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.

Application security consulting services by metro

  • Application security consulting services in London110

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 application security consulting services, 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 application security consulting services are there based in the United Kingdom?

RevenueBase identified 288 application security consulting services 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?

Turnkey Consulting, headquartered in London, tops this list with the largest team on record.

Which city has the most application security consulting services?

London leads with 110 headquartered companies, followed by Manchester (13) and Birmingham (7).

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 659 verified decision-maker contacts tracked across these 288 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 21, 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.