Company lists · Data refreshed September 2026

Top 25 Mobile app security testing firms based in the United Kingdom

RevenueBase identified 76 mobile app security testing firms headquartered in the United Kingdom as of September 2026 and tracks 669 professional contacts across them, including 191 with verified work emails. London is the largest hub.

This list covers mobile app security testing firms 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
76Companies
669Contacts tracked
191Verified emails
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The 25 largest mobile app security testing firms based in the United Kingdom

Ranked by team size
Top 25 of 76 mobile app security testing firms 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 mobile app security testing firms: 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 evidenceLeeds, United KingdomHQ checked Sep 21, 202651-20099 contacts →

Strong 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
2Indirect 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
3Partial evidenceLondon, United KingdomHQ checked Sep 21, 202611-5015 contacts →

Partial 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
4Partial evidenceHolborn, United KingdomHQ checked Sep 21, 20261-1013 contacts →

Partial evidence

“Laburity: Cyber Security Research and Services Company.”

Source: RevenueBase Database · checked Sep 21, 2026
5Partial evidenceMilton Keynes, United KingdomHQ checked Sep 21, 202611-5012 contacts →

Partial evidence

“We offer specialist CREST & CHECK Approved Penetration Testing services in order to secure our clients most critical assets.”

Source: RevenueBase Database · checked Sep 21, 2026
6Strong evidenceBelfast, United KingdomHQ checked Sep 21, 202611-5012 contacts →

Strong evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
7Partial evidenceBath, United KingdomHQ checked Sep 21, 202611-5011 contacts →

Partial 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
8Partial evidenceManchester, United KingdomHQ checked Sep 21, 202611-508 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 21, 2026
9Strong evidenceManchester, United KingdomHQ checked Sep 21, 20261-107 contacts →

Strong evidence

“RM Information Security are a specialist penetration testing and information security consultancy based in the north of England.”

Source: RevenueBase Database · checked Sep 21, 2026
10Indirect evidenceLondon, United KingdomHQ checked Sep 21, 20261-106 contacts →

Indirect evidence

“Appsecco Inc.”

Source: RevenueBase Database · checked Sep 21, 2026
11Indirect evidenceCranfield, United KingdomHQ checked Sep 21, 202611-506 contacts →

Indirect evidence

“Secure Debug: Your Full-Spectrum Cybersecurity Guardian!”

Source: RevenueBase Database · checked Sep 21, 2026
12Partial evidenceLondon, United KingdomHQ checked Sep 21, 20261-105 contacts →

Partial evidence

“Every engagement led by consultants with 10-20 years of offensive security experience.”

Source: RevenueBase Database · checked Sep 21, 2026
13Partial evidenceGaerwen, United KingdomHQ checked Sep 21, 20261-104 contacts →

Partial evidence

“Your Trusted CREST Certified Penetration Testing Partner.”

Source: RevenueBase Database · checked Sep 21, 2026
14Strong evidenceLondon, United KingdomHQ checked Sep 21, 20261-104 contacts →

Strong evidence

“We specialise in helping organisations identify security concerns and quantify the risks you may have across your assets, using Penetration Testing, Threat Simulation and…”

Source: RevenueBase Database · checked Sep 21, 2026
15Strong evidenceLondon, United KingdomHQ checked Sep 21, 202611-504 contacts →

Strong evidence

“At CyberSanctus, we specialize in offensive security and penetration testing services designed to identify real-world risks before attackers do.”

Source: RevenueBase Database · checked Sep 21, 2026
16Strong evidenceStevenage, United KingdomHQ checked Sep 21, 202611-503 contacts →

Strong evidence

“Armadillo Sec Ltd, a Chess Group company, are a specialist cyber security testing organisation, offering expert penetration testing, simulated attack testing, vulnerability…”

Source: RevenueBase Database · checked Sep 21, 2026
17Partial evidenceLeeds, United KingdomHQ checked Sep 21, 20261-103 contacts →

Partial evidence

“CodeGrazer is the newly formed pentest firm based in Leeds, UK, offering security services to protect private companies internal infrastructure and web services with quick…”

Source: RevenueBase Database · checked Sep 21, 2026
18Partial evidenceMilton Keynes, United KingdomHQ checked Sep 21, 202611-503 contacts →

Partial evidence

“Founded in London in 2019, Pyramid Ledger is a leading cybersecurity firm dedicated to enhancing digital security with comprehensive and bespoke solutions.”

Source: RevenueBase Database · checked Sep 21, 2026
19Strong evidenceLondon, United KingdomHQ checked Sep 21, 20261-103 contacts →

Strong evidence

“At Securityium, we're dedicated to transforming the way you experience security testing for your business.”

Source: RevenueBase Database · checked Sep 21, 2026
20Indirect evidenceLondon, United KingdomHQ checked Sep 21, 20261-103 contacts →

Indirect evidence

“CyberLegion is a UK/EU-based cybersecurity company helping organizations build, test and operate secure digital products.”

Source: RevenueBase Database · checked Sep 21, 2026
21Indirect evidenceCambridge, United KingdomHQ checked Sep 21, 202611-502 contacts →

Indirect evidence

“We believe that effective cybersecurity is within the reach of every organisation.”

Source: RevenueBase Database · checked Sep 21, 2026
22Partial evidenceWorcester, United KingdomHQ checked Sep 21, 20261-102 contacts →

Partial evidence

“We are a team of well-trained and experienced cybersecurity professionals that offer a multitude of testing, such as: Web application, Infrastructure penetration, Android…”

Source: RevenueBase Database · checked Sep 21, 2026
23Partial evidenceStevenage, United KingdomHQ checked Sep 21, 20261-102 contacts →

Partial evidence

“We are a selected team of UK based security professionals.”

Source: RevenueBase Database · checked Sep 21, 2026
24Partial evidenceLeeds, United KingdomHQ checked Sep 21, 202611-502 contacts →

Partial evidence

“Dhound is a cybersecurity company providing web application penetration testing, focused on manual approach and comprehensive delivery, helping IT companies be secure and…”

Source: RevenueBase Database · checked Sep 21, 2026
25Strong evidenceOxford, United KingdomHQ checked Sep 21, 20261-102 contacts →

Strong evidence

“The Traced app is a free mobile security app that protects users of both Android and iOS devices.”

Source: RevenueBase Database · checked Sep 21, 2026

Showing 25 of 76 mobile app security testing firms based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 191 reachable decision-makers.

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Mobile app security testing firms based in the United Kingdom at a glance

As of Sep 21, 2026
28.6%Verified-email coverage
8.8Average contacts per company
1-10Median size (employees)
40.8%Largest-city concentration · London
Sep 21, 2026Page data refreshed

Companies by employee count

1-10
52
11-50
21
51-200
2
201-500
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 76 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 mobile app security testing firms, 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 “mobile app security testing firms”. 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 mobile app security testing firms), 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 mobile app security testing firms, 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, 191 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.

Mobile app security testing firms by metro

  • Mobile app security testing firms in London31

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 mobile app security testing firms, 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 mobile app security testing firms are there based in the United Kingdom?

RevenueBase identified 76 mobile app security testing firms 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?

Appcheck LTD, headquartered in Leeds, tops this list with the largest team on record.

Which city has the most mobile app security testing firms?

London leads with 31 headquartered companies, followed by Leeds (4) and Manchester (4).

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 191 verified decision-maker contacts tracked across these 76 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.