Company lists · Data refreshed September 2026

Top 25 Appsec consulting firms based in the United Kingdom

Name: Appsec consulting firms based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 21, 2026 777 companies tracked

RevenueBase identified 777 company matches for appsec consulting firms associated with the United Kingdom as of September 2026 and tracks 7,000 professional contacts across them, including 2,255 with verified work emails. London is the largest hub.

This list covers company matches for appsec consulting firms 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 September 21, 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 Sep 21, 2026 How this list was built

777Companies

7,000Contacts tracked

2,255Verified emails

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The 25 largest appsec consulting firms based in the United Kingdom

Ranked by team size

Top 25 of 777 company matches for appsec consulting firms based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Sep 21, 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.
#	Company	RevenueBase SmartSearch	Headquarters	Employees	Contacts
1	COBRA	Exact match	London, United KingdomHQ recorded Sep 21, 2026	n/a	705 contacts →
	Exact match “Get a free, powerful security assessment with personalised recommendations, the same analysis that costs from IT Consultancies.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
2	Portswigger	Exact match	Knutsford, United KingdomHQ recorded Sep 21, 2026	51-200	267 contacts →
	Exact match “PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
3	Xalient	Exact match	Leeds, United KingdomHQ recorded Sep 21, 2026	201-500	260 contacts →
	Exact match “We are a global boutique, specializing exclusively in the convergence of identity-driven security and networking.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
4	Turnkey Consulting	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	134 contacts →
	Exact match “Turnkey Consulting brings together people, protection, and performance to help the world’s leading companies understand and optimize their risk and security landscape.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
5	Trpglobal	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	126 contacts →
	Exact match “We are TRPGLOBAL, your strategic partner in helping you with the complexities of risk management.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
6	Bulletproof Cyber Security	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	123 contacts →
	Exact match “Bulletproof is now part of WorkNest Secure.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
7	Caretower An Integrity360 Company	Exact match	London, United KingdomHQ recorded Sep 21, 2026	201-500	97 contacts →
	Exact match “As an independent IT security specialist, Caretower provide comprehensive solutions to individual problems, thus allowing our recommendations to be unbiased.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
8	Cognisys	Exact match	Leeds, United KingdomHQ recorded Sep 21, 2026	51-200	90 contacts →
	Exact match “Solutions \| Testing \| Knowledge Helping You Protect Your Business From Cyber Attackers Your security and compliance partner, delivering trust worldwide Cognisys are your trusted…” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
9	Amethyst Risk Management	Exact match	Basingstoke, United KingdomHQ recorded Sep 21, 2026	11-50	85 contacts →
	Exact match “Amethyst Risk Management is a leading cybersecurity consultancy supplying expert services and support to the UK Government, Defence, Operators of Essential Services, and the…” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
10	Foregenix	Exact match	Swindon, United KingdomHQ recorded Sep 21, 2026	51-200	80 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
11	Saepio Information Security	Exact match	High Wycombe, United KingdomHQ recorded Sep 21, 2026	51-200	74 contacts →
	Exact match “Saepio increase awareness, reduce risk and improve security in a continually evolving threat landscape.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
12	Dionach By Nomios	Exact match	Oxford, United KingdomHQ recorded Sep 21, 2026	51-200	73 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 · Sep 21, 2026 · View company records in RevenueBase
13	CSA Cyber	Exact match	Gloucester, United KingdomHQ recorded Sep 21, 2026	51-200	69 contacts →
	Exact match “Modern cyber resilience demands more than isolated controls.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
14	Covertswarm	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	64 contacts →
	Exact match “YOU DESERVE TO BE HACKED®.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
15	MDSEC	Exact match	Macclesfield, United KingdomHQ recorded Sep 21, 2026	11-50	61 contacts →
	Exact match “MDSec are a UK based consultancy with a passion for information security.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
16	Evalian	Exact match	Southampton, United KingdomHQ recorded Sep 21, 2026	51-200	60 contacts →
	Exact match “Many organisations are dealing with multiple frameworks, overlapping tools, disconnected ownership, and increasing pressure from regulators, customers, and boards.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
17	Cyberlab	Exact match	Alderley Edge, United KingdomHQ recorded Sep 21, 2026	51-200	57 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
18	Secureflag	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	57 contacts →
	Exact match Recorded description not available. Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
19	Riversafe	Exact match	London, United KingdomHQ recorded Sep 21, 2026	11-50	57 contacts →
	Exact match “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…” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
20	Purecyber Limited	Exact match	Cardiff, United KingdomHQ recorded Sep 21, 2026	11-50	49 contacts →
	Exact match “PureCyber is an award-winning, expert Cyber Security Consultancy.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
21	Cornerstone	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	44 contacts →
	Exact match “CornerStone is an award winning, independent, security and digital building consulting firm with headquarters in the UK.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
22	RED Team Partners	Exact match	London, United KingdomHQ recorded Sep 21, 2026	51-200	44 contacts →
	Exact match “Our Red Team security consultants are elite technical experts with worldwide Red Team service experience, and a respected reputation of delivering red team services for SME’s.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
23	Coretech Security	Exact match	Cheltenham, United KingdomHQ recorded Sep 21, 2026	51-200	42 contacts →
	Exact match “CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
24	Secforce LTD	Exact match	London, United KingdomHQ recorded Sep 21, 2026	11-50	39 contacts →
	Exact match “SECFORCE are vendor independent offensive security specialists providing effective business risk intelligence and strategic security consulting.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase
25	Omerta	Exact match	Saffron Walden, United KingdomHQ recorded Sep 21, 2026	51-200	38 contacts →
	Exact match “Omerta - A Global Security Technology and Services Company.” Recorded in the RevenueBase company graph · Sep 21, 2026 · View company records in RevenueBase

RevenueBase SmartSearch

Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.

This list uses Exact for “appsec consulting firms”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.

Showing 25 of 777 appsec consulting firms based in the United Kingdom

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Appsec consulting firms based in the United Kingdom at a glance

As of Sep 21, 2026

32.2%Verified-email coverage

9.0Average contacts per company

1-10Median size (employees)

39.0%Largest-city concentration · London

Sep 21, 2026Page data refreshed

Companies by employee count

1-10

538

11-50

185

51-200

201-500

501-1,000

1,001-5,000

5,001-10,000

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 777 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 “appsec consulting firms” 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 2,255 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 September 21, 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 “appsec consulting firms”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many appsec consulting firms are there based in the United Kingdom?

RevenueBase identified 777 company matches for appsec consulting firms associated with the United Kingdom as of September 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?

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

Which city has the most appsec consulting firms?

London leads with 303 company records, followed by Manchester (28) and Birmingham (17).

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 2,255 professional contacts with verified work emails tracked across these 777 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 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 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.