Company lists · Data refreshed August 2026

Top 25 Api security companies based in the United Kingdom

RevenueBase identified 382 company matches for api security companies associated with the United Kingdom as of August 2026 and tracks 4,477 professional contacts across them, including 1,231 with verified work emails and 338 with mobile numbers. London is the largest hub.

This list covers company matches for api security 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 August 31, 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 Aug 31, 2026 How this list was built
382Companies
4,477Contacts tracked
1,231Verified emails
338Mobile numbers
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The 25 largest api security companies based in the United Kingdom

Ranked by team size
Top 25 of 382 company matches for api security companies based in the United Kingdom, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Aug 31, 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 matchLeicester, United Kingdom201-500739 contacts →

Exact match

“SISA is a global forensics-driven cybersecurity solutions company, trusted by leading organizations for securing their businesses with robust preventive, detective, and corrective…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
2Exact matchThatcham, United Kingdom51-200160 contacts →

Exact match

“At Cyberfort we are passionate about the cyber security services we deliver for our customers which keeps their people, data, systems and technology infrastructure secure…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
3Exact matchLondon, United Kingdom51-200118 contacts →

Exact match

“Bulletproof is now part of WorkNest Secure.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
4Exact matchFarnborough, United Kingdom51-200100 contacts →

Exact match

“As the world becomes more connected, our lives and businesses are more vulnerable.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
5Exact matchWaterloo, United Kingdom51-20080 contacts →

Exact match

“At Reliance Cyber, we believe in truly partnering with our customers.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
6Exact matchLincoln, United Kingdom51-20056 contacts →

Exact match

“CyberLab is the UK-leading cyber security consultancy and managed services provider, trusted by over 1,200 enterprise businesses, government departments, and household names to…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
7Exact matchLondon, United Kingdom51-20052 contacts →

Exact match

“At Hexegic we are not just passionate about protecting data through our Cyber services we are passionate about helping companies release the potential of the data they hold…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
8Exact matchEdinburgh, United Kingdom201-50052 contacts →

Exact match

“We are Adarma, independent leaders in detection and response services.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
9Exact matchCheltenham, United Kingdom51-20041 contacts →

Exact match

“CoreTech is a specialist cyber security company whose people are motivated by the desire to deliver exceptional capabilities coupled with a real sense of mission.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
10Exact matchManchester, United Kingdom11-5034 contacts →

Exact match

“Secarma exists to keep the world safe.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
11Exact matchStevenage, United Kingdom51-20032 contacts →

Exact match

“Defense.com is transforming the way businesses manage cyber security by allowing them to easily identify, prioritise and remediate threats.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
12Exact matchBirmingham, United Kingdom11-5032 contacts →

Exact match

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

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
13Exact matchBailrigg, United Kingdom11-5030 contacts →

Exact match

“Cyber security can feel overwhelming.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
14Exact matchLondon, United Kingdom51-20025 contacts →

Exact match

“Encode is now part of Obrela Security Industries collectively delivering cutting edge Cyber Security Services, empowering organizations to better protect against cyber threats.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
15Exact matchPeterborough, United Kingdom51-20024 contacts →

Exact match

“Check Point Partner of the Year 2022 CRN MSSP of the Year 2021 Pentesec has been challenging the status quo in Cyber Security since 2014 when 5 industry veterans decided they were…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
16Exact matchLondon, United Kingdom11-5024 contacts →

Exact match

“Redfox Cybersecurity is a fast-growing cybersecurity consulting firm, spread across 4 countries.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
17Exact matchLondon, United Kingdom51-20024 contacts →

Exact match

“SSL247 (A Sectigo Company) has nearly 20 years of security consulting experience operating in 18 different markets globally.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
18Exact matchLondon, United Kingdom11-5020 contacts →

Exact match

“Secure Purple is a leading cyber security and digital safety firm that provides innovative solutions and services to help organisations and individuals stay protected in the…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
19Exact matchLondon, United Kingdom11-5019 contacts →

Exact match

“th4ts3cur1ty.company supplies cyber security services internationally.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
20Exact matchLeeds, United Kingdom11-5019 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 · Aug 31, 2026 · View company records in RevenueBase
21Exact matchLondon, United Kingdom11-5017 contacts →

Exact match

“We are a London based specialist supplier of cyber defence solution and information security services.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
22Exact matchCheltenham, United Kingdom11-5016 contacts →

Exact match

“B10SEC is a company specialising in cybersecurity and data protection services and solutions, headquartered in Gloucestershire, UK, with branches in Portugal, Brazil and Mexico.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
23Exact matchBirmingham, United Kingdom201-50015 contacts →

Exact match

“Best penetration testing service - Teiss Awards 2024 Managed cloud service winner - Stratus Awards 2023 Security vendor of the year - Computing security excellence awards 2023…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
24Exact matchLondon, United Kingdom11-5015 contacts →

Exact match

“is an ISO 9001:2015 and ISO/IEC 27001:2022 certified, DPIIT-recognized cybersecurity company delivering structured External Vulnerability Assessment & Penetration Testing (VAPT)…”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase
25Exact matchLondon, United Kingdom51-20014 contacts →

Exact match

“Who We Are DataSixth delivers Cybersecurity Intelligence.”

Recorded in the RevenueBase company graph · Aug 31, 2026 · View company records in RevenueBase

Showing 25 of 382 api security companies based in the United Kingdom

See the full list, filter by size, metro and specialty, and access 1,231 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Api security companies based in the United Kingdom at a glance

As of Aug 31, 2026
27.5%Verified-email coverage
7.5%Mobile-number coverage
11.7Average contacts per company
1-10Median size (employees)
41.9%Largest-city concentration · London
Aug 31, 2026Page data refreshed

Companies by employee count

1-10
223
11-50
124
51-200
25
201-500
6
501-1,000
3
1,001-5,000
1

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 security 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 1,231 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 August 31, 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 security 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 security companies”; each Exact match badge shows search membership, not an individual similarity or quality score.

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

RevenueBase identified 382 company matches for api security companies associated with the United Kingdom as of August 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?

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

Which city has the most api security companies?

London leads with 160 company records, followed by Manchester (18) and Cheltenham (12).

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 1,231 professional contacts with verified work emails tracked across these 382 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 August 31, 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.