Company lists · Data refreshed September 2026
Top 25 Api security consulting companies based in the United Kingdom
RevenueBase identified 122 api security consulting companies headquartered in the United Kingdom as of September 2026 and tracks 1,566 professional contacts across them, including 201 with verified work emails. London is the largest hub.
This list covers api security consulting 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 api security consulting companies based in the United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 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. | |||||
| 2 | 36 contacts → | ||||
Indirect evidence “Secarma exists to keep the world safe.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 3 | 30 contacts → | ||||
Partial evidence “Cyber security can feel overwhelming.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 4 | 26 contacts → | ||||
Partial evidence “Based in Manchester UK, we are an independent Cyber Security Consultancy providing Security services across a wide range of markets, from multi-national Corporate Organisations…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 5 | 21 contacts → | ||||
Partial evidence “Chaleit is a cyber security management consultancy that aligns business context with real-world capability to solve complex risks.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 6 | 20 contacts → | ||||
Indirect evidence “We help organisations achieve business-focused cybersecurity compliance across various industry and regulatory frameworks with successful stakeholder management, particularly in…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 7 | 19 contacts → | ||||
Partial evidence “Razorthorn Security is a specialist cybersecurity consultancy founded in 2007, with nearly two decades of experience helping organisations protect their data, their systems and…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 8 | 17 contacts → | ||||
Partial evidence “We are a cyber security consultancy that specialises in security solution architecture, engineering, implementation and operational support.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 9 | 15 contacts → | ||||
Indirect 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 27, 2026Thanks. The Data Team will review it. | |||||
| 10 | 14 contacts → | ||||
Partial evidence “Demand more from your AI & Data Security partner.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 11 | 12 contacts → | ||||
Indirect evidence “We offer specialist CREST & CHECK Approved Penetration Testing services in order to secure our clients most critical assets.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 12 | 11 contacts → | ||||
Strong evidence “At 2|SEC Consulting, we deliver an end-to-end service of cyber and information security solutions which are tailored to each client’s exact security needs.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 13 | 10 contacts → | ||||
Partial evidence “After being frustrated in the way that Cyber Security services were being delivered to organisations, Cyberhash was founded with a fresh approach to Cyber Security - keeping you…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 14 | 7 contacts → | ||||
Strong evidence “Kloudwerk offers a game-changing approach to cyber security consulting for SMEs.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 15 | 7 contacts → | ||||
Partial evidence “RM Information Security are a specialist penetration testing and information security consultancy based in the north of England.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 16 | 7 contacts → | ||||
Partial evidence “Kelltron Consulting Services is a globally recognized cybersecurity consulting firm with a strong presence in the United Kingdom, United States, and India.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 17 | 6 contacts → | ||||
Indirect evidence “Appsecco Inc.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 18 | 6 contacts → | ||||
Indirect evidence “Secure Debug: Your Full-Spectrum Cybersecurity Guardian!” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 19 | 5 contacts → | ||||
Partial evidence “Every engagement led by consultants with 10-20 years of offensive security experience.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 20 | 4 contacts → | ||||
Partial evidence “After spending over a decade working in the cyber security industry, I noticed that many organisations that once specialised in penetration testing were being bought out or had…” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 21 | 4 contacts → | ||||
Strong evidence “Novous is a results-focused company that provides high-quality Software Development, IT and Security Consulting services.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 22 | 3 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 27, 2026Thanks. The Data Team will review it. | |||||
| 23 | 2 contacts → | ||||
Indirect evidence “For our latest updates, please visit our company page 'KT Secure'.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 24 | 2 contacts → | ||||
Indirect evidence “Adversify is a CREST-accredited boutique cybersecurity consultancy founded in 2022 with a clear focus on delivering high-quality, outcome-driven penetration testing.” Source: RevenueBase Database · checked Sep 27, 2026Thanks. The Data Team will review it. | |||||
| 25 | 2 contacts → | ||||
Partial evidence “Identity9 provides strategic consulting and managed services to both enterprise business and cyber insurance providers.” 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: api security 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 api security consulting companies.
- Partial evidence
- Its own public description names part of api security consulting companies, so it works in or next to the category without describing itself that way.
- Indirect evidence
- The description shown does not name api security 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 122 api security consulting companies based in the United Kingdom
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Api security consulting 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 122 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 api security 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 the United Kingdom whose own description of what they do matches “api security 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 api security 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 api security consulting 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, 201 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.
Api security consulting companies by metro
- Api security consulting companies in London49
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 api security 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 api security consulting companies are there based in the United Kingdom?
RevenueBase identified 122 api security consulting 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?
MDSEC, headquartered in Macclesfield, tops this list with the largest team on record.
Which city has the most api security consulting companies?
London leads with 49 headquartered companies, followed by Manchester (5) and Basingstoke (3).
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 201 verified decision-maker contacts tracked across these 122 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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