Company lists · Data refreshed September 2026
Top 25 Application security products and services providers based in the United Kingdom
RevenueBase identified 93 application security products and services providers headquartered in the United Kingdom as of September 2026 and tracks 1,279 professional contacts across them, including 409 with verified work emails. London is the largest hub.
This list covers application security products and services providers 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.
The 25 largest application security products and services providers based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 267 contacts → | ||||
Strong evidence “PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 2 | 99 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, 2026Thanks. The Data Team will review it. | |||||
| 3 | 61 contacts → | ||||
Partial evidence “Intruder's continuous exposure management platform helps security, IT, and engineering teams stop breaches before they start.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 4 | 57 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 5 | 57 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, 2026Thanks. The Data Team will review it. | |||||
| 6 | 36 contacts → | ||||
Indirect evidence “Secarma exists to keep the world safe.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 7 | 30 contacts → | ||||
Strong evidence “SnapSec is a cybersecurity company specializing in centralized application security operations.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 8 | 28 contacts → | ||||
Indirect evidence “Licel is a mobile channel protection company.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 9 | 25 contacts → | ||||
Partial evidence “Critical Endpoint Security | Unified Endpoint Management | Business Continuity Assessment Services | Resource Support and Consultancy | Powered by Tanium | Trend Micro Partner |…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 10 | 24 contacts → | ||||
Partial evidence “Nanjgel Solutions is focused on delivering the best IT security for businesses.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 11 | 19 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, 2026Thanks. The Data Team will review it. | |||||
| 12 | 14 contacts → | ||||
Partial evidence “CloudSecure delivers secure software and cloud systems for security-critical environments.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 13 | 11 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, 2026Thanks. The Data Team will review it. | |||||
| 14 | 9 contacts → | ||||
Partial evidence “Formed in 2010, Security Software Solutions Ltd (S3 Ltd) has become a recognised force in Enterprise Security Solutions in Europe.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 15 | 8 contacts → | ||||
Indirect evidence “Cytix is the AppSec layer that focuses testing where it matters.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 16 | 6 contacts → | ||||
Indirect evidence “Appsecco Inc.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 17 | 6 contacts → | ||||
Indirect evidence “Secure Debug: Your Full-Spectrum Cybersecurity Guardian!” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 18 | 6 contacts → | ||||
Partial evidence “We provide market-leading cybersecurity products to protect your mobile devices and computers from malicious attacks, identity theft and fraud.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 19 | 4 contacts → | ||||
Partial 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, 2026Thanks. The Data Team will review it. | |||||
| 20 | 3 contacts → | ||||
Partial evidence “CyberSafe is the original commercial provider of Kerberos-based security solutions, with over 20 years' experience, and focused on providing innovative security solutions for SAP…” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 21 | 3 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, 2026Thanks. The Data Team will review it. | |||||
| 22 | 3 contacts → | ||||
Strong evidence “Zeroday Co, Ltd is a company focusing on developing and delivering state-of-art application security testing tools/platforms.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 23 | 3 contacts → | ||||
Partial evidence “AVm has many years experience and expertise in IT security.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 24 | 3 contacts → | ||||
Partial evidence “At Securityium, we're dedicated to transforming the way you experience security testing for your business.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
| 25 | 3 contacts → | ||||
Partial evidence “CyberLegion is a UK/EU-based cybersecurity company helping organizations build, test and operate secure digital products.” Source: RevenueBase Database · checked Sep 21, 2026Thanks. The Data Team will review it. | |||||
RevenueBase Smart Search
RevenueBase Smart Search assesses information from a company’s LinkedIn profile, information supplied directly by the company, its website, and other publicly available sources. It uses that information to rate how closely the company relates to this list’s category: application security products and services providers. Every row carries its rating and the description the rating was read from, so each one can be checked rather than taken on trust.
- Strong evidence
- The company's own public description of its business names application security products and services providers.
- Partial evidence
- Its own public description names part of application security products and services providers, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name application security products and services providers. The match rests on the rest of the company's public profile rather than the one sentence quoted here, so this is the rating to check first.
RevenueBase Smart Search is how these lists are built: RevenueBase's data engine and AI assemble the companies that match a category defined in a user's own words, so a list can be about what companies actually do rather than about whichever industry code they were filed under.
Showing 25 of 93 application security products and services providers based in the United Kingdom
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Application security products and services providers based in the United Kingdom at a glance
As of Sep 21, 2026Companies by employee count
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 93 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 products and services providers, 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 products and services providers”. 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 products and services providers), 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 products and services providers, 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, 409 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 products and services providers by metro
- Application security products and services providers in London44
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 products and services providers, 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 products and services providers are there based in the United Kingdom?
RevenueBase identified 93 application security products and services providers 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?
Portswigger, headquartered in United Kingdom, tops this list with the largest team on record.
Which city has the most application security products and services providers?
London leads with 44 headquartered companies, followed by Leeds (5) 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 409 verified decision-maker contacts tracked across these 93 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.
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