Company lists · Data refreshed September 2026

Top 25 Secure software development consulting companies based in London, United Kingdom

Name: Secure software development consulting companies based in London, United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 29, 2026 241 companies tracked

RevenueBase identified 241 secure software development consulting companies headquartered in London, United Kingdom as of September 2026 and tracks 1,419 professional contacts across them, including 365 with verified work emails. Across the United Kingdom, London is the largest hub for this category.

This list covers secure software development consulting companies headquartered in London, 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 29, 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 29, 2026 86% judged on-target in blind review

241Companies

1,419Contacts tracked

365Verified emails

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The 25 largest secure software development consulting companies based in London, United Kingdom

Ranked by team size

Top 25 of 241 secure software development consulting companies based in London, United Kingdom, ranked by team size, largest first. Data refreshed Sep 29, 2026. RevenueBase Smart Search rates how each company's information relates to secure software development consulting companies: 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.
#	Company	RevenueBase Smart Search	Headquarters	Employees	Contacts
1	Caretower An Integrity360 Company	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	201-500	97 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 29, 2026
2	Xynotech	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	96 contacts →
	Strong evidence “Xynotech is a provider of IT consulting and software development services that help companies overtake their competition.” Source: RevenueBase Database · checked Sep 29, 2026
3	Clurgo	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	76 contacts →
	Partial evidence “Clurgo empowers global enterprises and early ventures to deliver software at higher velocity and better quality.” Source: RevenueBase Database · checked Sep 29, 2026
4	Gemba Advantage	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	59 contacts →
	Strong evidence “Gemba Advantage make high-impact software that is secure, scalable and sustainable.” Source: RevenueBase Database · checked Sep 29, 2026
5	Secureflag	Indirect evidence	London, United KingdomHQ checked Sep 29, 2026	51-200	57 contacts →
	Indirect evidence Source: RevenueBase Database · checked Sep 29, 2026
6	Riversafe	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	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 29, 2026
7	IT Grids LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	33 contacts →
	Partial evidence “IT Grids is a global information technology (IT) services company offering span technology consulting, domain consulting, application services, systems integration, custom…” Source: RevenueBase Database · checked Sep 29, 2026
8	Leapsight	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	25 contacts →
	Strong evidence “We are an innovative software boutique consulting firm where extraordinary business insight meets technical excellence.” Source: RevenueBase Database · checked Sep 29, 2026
9	TGA Digital LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	23 contacts →
	Strong evidence “TGA Digital is a software engineering consultancy focussed on delivering high quality software projects as well as consulting, due diligence, trouble shooting and fund raising.” Source: RevenueBase Database · checked Sep 29, 2026
10	LMS Security	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	20 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 29, 2026
11	Olive JAR Digital	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	20 contacts →
	Partial evidence “Olive Jar Digital has extensive experience in building highly secure, resilient, highly available and scalable websites.” Source: RevenueBase Database · checked Sep 29, 2026
12	Fortyseven Software Professionals	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	501-1,000	18 contacts →
	Strong evidence “FortySeven Software Professionals (FSSP) is a European based IT consulting and full-cycle software development company.” Source: RevenueBase Database · checked Sep 29, 2026
13	Jags Consultancy LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	15 contacts →
	Strong evidence “Jags Consultancy Limited is an IT consulting and software development company founded in 2015, headquartered out of UK.” Source: RevenueBase Database · checked Sep 29, 2026
14	CYTAL	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	11 contacts →
	Partial evidence “CyTAL exists to help developers, manufacturers and their customers to improve the security and resilience of products and systems.” Source: RevenueBase Database · checked Sep 29, 2026
15	Stratia Cyber	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	8 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 29, 2026
16	Luminara Software	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	7 contacts →
	Strong evidence “Luminara Software Limited is a software consultancy and development based in London, United Kingdom.” Source: RevenueBase Database · checked Sep 29, 2026
17	Kloudwerk	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	7 contacts →
	Strong evidence “Kloudwerk offers a game-changing approach to cyber security consulting for SMEs.” Source: RevenueBase Database · checked Sep 29, 2026
18	Refineri	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	11-50	6 contacts →
	Partial evidence “REFINERI provides the information technology consulting you need to realise your ambitions.” Source: RevenueBase Database · checked Sep 29, 2026
19	Fortbridge	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	5 contacts →
	Partial evidence “Every engagement led by consultants with 10-20 years of offensive security experience.” Source: RevenueBase Database · checked Sep 29, 2026
20	Smart BEE Software Solutions LTD	Strong evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	4 contacts →
	Strong evidence “SmartBee,(Smart Bee Software Solutions Ltd.) majorly focuses on consultancy services for Architectural Software Designs and Full-Stack Software Development in technologies like…” Source: RevenueBase Database · checked Sep 29, 2026
21	Oppian Systems LTD	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Partial evidence “Oppian is a group of creative and passionate technologists with a wealth of experience gained from the forefront of mobile and web development, working with companies like Apple…” Source: RevenueBase Database · checked Sep 29, 2026
22	Logicful	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Partial evidence “A software consultancy with a passion for delivering fast, high quality results for your company.” Source: RevenueBase Database · checked Sep 29, 2026
23	L4g	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Partial evidence “A tech passionates, software developers and consultants.” Source: RevenueBase Database · checked Sep 29, 2026
24	Aliud Solutions	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	3 contacts →
	Partial evidence “Aliud Solutions is a UK-based IT consultancy specialising in secure, scalable systems for government and enterprise clients.” Source: RevenueBase Database · checked Sep 29, 2026
25	Cyberlegion	Partial evidence	London, United KingdomHQ checked Sep 29, 2026	1-10	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 29, 2026

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: secure software development consulting 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 secure software development consulting companies.
Partial evidence: Its own public description names part of secure software development consulting companies, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name secure software development consulting 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 241 secure software development consulting companies based in London, United Kingdom

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Secure software development consulting companies based in London, United Kingdom at a glance

As of Sep 29, 2026

25.7%Verified-email coverage

5.9Average contacts per company

1-10Median size (employees)

Sep 29, 2026Page data refreshed

Companies by employee count

1-10

185

11-50

51-200

201-500

501-1,000

Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 241 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 secure software development consulting 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 London, United Kingdom whose own description of what they do matches “secure software development consulting 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 secure software development consulting 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 secure software development consulting companies, and records with no verified work email. Companies headquartered outside London 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, 365 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 29, 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.

Secure software development consulting companies by metro in the United Kingdom

Secure software development consulting companies in Manchester26

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 secure software development consulting 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 secure software development consulting companies are there based in London, United Kingdom?

RevenueBase identified 241 secure software development consulting companies headquartered in London, 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?

Caretower An Integrity360 Company, headquartered in London, tops this list with the largest team on record.

Which city in the United Kingdom has the most secure software development consulting companies?

London leads the United Kingdom with 241 headquartered companies, followed by Manchester (26) and Cambridge (15).

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 365 verified decision-maker contacts tracked across these 241 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 29, 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.