Company lists · Data refreshed September 2026
Top 25 Code security companies based in the United Kingdom
RevenueBase identified 497 code security companies headquartered in the United Kingdom as of September 2026 and tracks 3,861 professional contacts across them, including 691 with verified work emails. London is the largest hub.
This list covers code security 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, its RevenueBase Smart Search rating, and when it was last checked. Data refreshed September 27, 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 code security companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 267 contacts → | ||||
Partial evidence “PortSwigger is a global leader in the creation of software tools for security testing of web applications.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 2 | 70 contacts → | ||||
Partial evidence “With over 50 years’ experience in the security industry, Abel has grown to become one of the UK’s largest privately owned providers of electronic security systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 61 contacts → | ||||
Partial evidence “MDSec are a UK based consultancy with a passion for information security.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 57 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 57 contacts → | ||||
Partial 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 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 52 contacts → | ||||
Indirect evidence “Recognised nationally for our customer focused approach and commitment to excellence.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 52 contacts → | ||||
Partial evidence “Secur-it is a leading provider of security services and risk management.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 46 contacts → | ||||
Partial evidence “Risk Management Security Services specialise in providing bespoke security to commercial, residential and Industrial premises.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 44 contacts → | ||||
Partial evidence “Design, install and maintain CCTV Systems Intruder Systems Access Control Manned Security Guarding Event Stewarding Construction Cleaning Commercial Cleaning Builders & Sparkle…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 39 contacts → | ||||
Partial evidence “Alpha Omega Securities Ltd provides a wide range of professional services for the protection of clients, their property and their premises throughout the United Kingdom.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 36 contacts → | ||||
Partial evidence “Doyle Security Ltd is a leading provider of professional security solutions, proudly safeguarding businesses, homeowners, and their properties for over four decades.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 32 contacts → | ||||
Partial evidence “Zicam specialise in state-of-the-art security disciplines covering remotely monitored CCTV, Access Control, Fire Alarms, Permitter Protection and Intruder Alarm Systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 32 contacts → | ||||
Partial evidence “Founded in 1974, Lincoln Security Ltd.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 32 contacts → | ||||
Partial evidence “Security Specialists A discreet, reliable and effective service Providing highly trained professional security guards and associated round the clock security services and for over…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 31 contacts → | ||||
Partial evidence “Established in 1992, we are one of the largest security companies in Manchester and are now providing an extensive range of security services to our clients Nationwide.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 28 contacts → | ||||
Indirect evidence “Protecting homes and businesses since 1982.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 25 contacts → | ||||
Partial evidence “We're a multi-award-winning security company, specialising in Corporate, Commercial and Construction solutions.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 24 contacts → | ||||
Partial evidence “At 1st Ace Security we are specialists in providing security solutions across South London for both domestic and commercial properties.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 24 contacts → | ||||
Partial evidence “Close Protection Security is an industry-leading security company, established in 2017 and based in the North East of England, created by Glenn Bartlett.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 22 contacts → | ||||
Partial evidence “Based in Aberdeen, Inverness, and now also Glasgow, Aberdeen Alarm Company Ltd offer a range of solutions for your security, fire prevention and locksmith requirements.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 20 contacts → | ||||
Partial evidence “Advance Fire & Security Ltd is a leading provider of domestic and commercial security systems.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 20 contacts → | ||||
Indirect evidence Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 19 contacts → | ||||
Partial evidence “Bee Tee Alarms Ltd is a well established family owned business evolving from Dove Security, established in 1980 and taking its present identity in 1984.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 16 contacts → | ||||
Partial evidence “Webeye Limited, alongside Webeye Corp in the USA, is a leading provider of advanced security solutions for the professional security industry.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 16 contacts → | ||||
Partial evidence “DCA Security Systems Ltd is an electronic fire & security company based out of 6 The Progression Centre, Mark Road, Hemel Hempstead, Hertfordshire.” Source: RevenueBase Database · checked Sep 27, 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: code security companies. 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 code security companies.
- Partial evidence
- Its own public description names part of code security companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name code security companies. 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 497 code security companies based in the United Kingdom
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Code security companies based in the United Kingdom at a glance
As of Sep 27, 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 497 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 code security companies, 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 “code security companies”. 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 code security companies), 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 code security 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 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, 691 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 27, 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.
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 code security companies, 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 code security companies are there based in the United Kingdom?
RevenueBase identified 497 code security 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?
Portswigger, headquartered in United Kingdom, tops this list with the largest team on record.
Which city has the most code security companies?
London leads with 81 headquartered companies, followed by Manchester (11) and Birmingham (8).
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 691 verified decision-maker contacts tracked across these 497 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 27, 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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