Company lists · Data refreshed November 2026

Top 25 Api penetration testing companies based in the United Kingdom

RevenueBase identified 177 company matches for api penetration testing companies associated with the United Kingdom as of November 2026 and tracks 1,274 professional contacts across them, including 476 with verified work emails. London is the largest hub.

This list covers company matches for api penetration testing companies associated with the United Kingdom, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, 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 RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
177Companies
1,274Contacts tracked
476Verified emails
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The 25 largest api penetration testing companies based in the United Kingdom

Ranked by team size
Top 25 of 177 company matches for api penetration testing companies based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchLeeds, United KingdomHQ recorded Nov 6, 202651-200106 contacts →

Exact match

“AppCheck is a Complete Enterprise Security Testing Solution that provides up to the minute vulnerability coverage for your entire estate.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchMacclesfield, United KingdomHQ recorded Nov 6, 202611-5057 contacts →

Exact match

“MDSec are a UK based consultancy with a passion for information security.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchBasingstoke, United KingdomHQ recorded Nov 6, 202651-20051 contacts →

Exact match

“Rootshell Security delivers human-led, AI-augmented Continuous Testing and Operational Continuous Threat Exposure Management (CTEM).”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchBristol, United KingdomHQ recorded Nov 6, 202651-20049 contacts →

Exact match

“OnSecurity offers CREST-accredited AI Augmented Penetration Testing, all whilst harnessing technology to simplify the management and delivery of pentesting.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchManchester, United KingdomHQ recorded Nov 6, 202611-5042 contacts →

Exact match

“Secarma exists to keep the world safe.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchBirmingham, United KingdomHQ recorded Nov 6, 202611-5037 contacts →

Exact match

“Aristi is a specialist provider of cyber security services with over 17 years of experience.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchCambridge, United KingdomHQ recorded Nov 6, 202611-5032 contacts →

Exact match

“Pentesting Exams by Pentesting Experts.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchPortsmouth, United KingdomHQ recorded Nov 6, 202611-5029 contacts →

Exact match

“Imagine a world where cyber threats are simply another challenge that you're fully equipped to handle.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchLondon, United KingdomHQ recorded Nov 6, 202611-5029 contacts →

Exact match

“RedHunt Labs is a research-driven cybersecurity company delivering Continuous Threat Exposure Management (CTEM), PTaaS, and AI Exposure Security.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchAltrincham, United KingdomHQ recorded Nov 6, 202611-5029 contacts →

Exact match

“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…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchLondon, United KingdomHQ recorded Nov 6, 202611-5025 contacts →

Exact match

“Toro was founded on creating the UK's first Red Team penetration test - and then attacking hundreds of clients by hacking their systems, influencing / social engineering staff and…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchLeeds, United KingdomHQ recorded Nov 6, 202611-5023 contacts →

Exact match

“Halo I.S is not just another cybersecurity organization based in the UK; we're a testament to evolution and client-centric innovation.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchManchester, United KingdomHQ recorded Nov 6, 202611-5020 contacts →

Exact match

“Cytix is the security decision layer for a world where software development never stops.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchMilton Keynes, United KingdomHQ recorded Nov 6, 202611-5015 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchBath, United KingdomHQ recorded Nov 6, 202611-5014 contacts →

Exact match

“At Mobius Binary we care about your reputation and the loss that could result from violating your digital boundaries.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchHolborn, United KingdomHQ recorded Nov 6, 20261-1013 contacts →

Exact match

“Laburity: Cyber Security Research and Services Company.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchLondon, United KingdomHQ recorded Nov 6, 202611-5011 contacts →

Exact match

“SecureTeam are a UK-based information security practice, specialising in all areas of cybersecurity.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchGaerwen, United KingdomHQ recorded Nov 6, 20261-108 contacts →

Exact match

“Your Trusted CREST Certified Penetration Testing Partner.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchLeamington Spa, United KingdomHQ recorded Nov 6, 202611-507 contacts →

Exact match

“Building the best Cyber Security company you've never heard of.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchManchester, United KingdomHQ recorded Nov 6, 20261-107 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchCranfield, United KingdomHQ recorded Nov 6, 202611-507 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchBirmingham, United KingdomHQ recorded Nov 6, 202611-506 contacts →

Exact match

“Cyndicate Labs are a UK based Cyber Security consultancy.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchBlackpool, United KingdomHQ recorded Nov 6, 20261-106 contacts →

Exact match

“Akimbo Core are a Cybersecurity company offering Penetration Testing, Cybersecurity Training, and Consultancy.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchLondon, United KingdomHQ recorded Nov 6, 20261-106 contacts →

Exact match

“Appsecco Inc.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchLondon, United KingdomHQ recorded Nov 6, 20261-106 contacts →

Exact match

“We are a UK-based Cyber Security company offering a comprehensive portfolio specialising in innovative solutions for Penetration Testing, Training, Compliance, Consulting, and…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 25 of 177 api penetration testing companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 476 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Api penetration testing companies based in the United Kingdom at a glance

As of Nov 6, 2026
37.4%Verified-email coverage
7.2Average contacts per company
1-10Median size (employees)
36.2%Largest-city concentration · London
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
119
11-50
49
51-200
6
201-500
2
1,001-5,000
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 177 companies.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Company records associated with the United Kingdom whose business descriptions match “api penetration testing companies” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Where headquarters information is recorded, preview rows are also filtered to this page’s location. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
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 displayed company carries at least one verified work email. RevenueBase tracks 476 professional contacts with verified work emails across the full matched dataset. 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 November 6, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Api penetration testing companies by metro

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “api penetration testing companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many api penetration testing companies are there based in the United Kingdom?

RevenueBase identified 177 company matches for api penetration testing companies associated with the United Kingdom as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Appcheck LTD tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which city has the most api penetration testing companies?

London leads with 64 company records, followed by Manchester (13) and Birmingham (5).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 476 professional contacts with verified work emails tracked across these 177 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 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 SmartSearch, 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.