Company lists · Data refreshed September 2026

Top 25 Iot security testing companies based in the United Kingdom

RevenueBase identified 245 iot security testing companies headquartered in the United Kingdom as of September 2026 and tracks 2,089 professional contacts across them, including 836 with verified work emails. London is the largest hub.

This list covers iot security testing 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 28, 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 28, 2026 86% judged on-target in blind review
245Companies
2,089Contacts tracked
836Verified emails
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The 25 largest iot security testing companies based in the United Kingdom

Ranked by team size
Top 25 of 245 iot security testing companies based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 28, 2026. RevenueBase Smart Search rates how each company's information relates to iot security testing 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.
#CompanyRevenueBase Smart SearchHeadquartersEmployeesContacts
1Strong evidenceKnutsford, United KingdomHQ checked Sep 28, 202651-200267 contacts →

Strong evidence

“PortSwigger is a global leader in the creation of software tools for security testing of web applications.”

Source: RevenueBase Database · checked Sep 28, 2026
2Strong evidenceLeeds, United KingdomHQ checked Sep 28, 202651-20099 contacts →

Strong evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
3Partial evidenceOxford, United KingdomHQ checked Sep 28, 202651-20073 contacts →

Partial evidence

“Dionach by Nomios has over 25 years of expertise in information security, supporting organisations in building resilience against ever‑evolving cyber threats.”

Source: RevenueBase Database · checked Sep 28, 2026
4Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202651-20064 contacts →

Indirect evidence

“YOU DESERVE TO BE HACKED®.”

Source: RevenueBase Database · checked Sep 28, 2026
5Partial evidenceMacclesfield, United KingdomHQ checked Sep 28, 202611-5061 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
6Strong evidenceLondon, United KingdomHQ checked Sep 28, 202651-20051 contacts →

Strong evidence

“Redscan is an award-winning provider of managed security services, specialising in Managed Detection and Response, Penetration Testing and Red Teaming.”

Source: RevenueBase Database · checked Sep 28, 2026
7Partial evidenceBasingstoke, United KingdomHQ checked Sep 28, 202651-20049 contacts →

Partial evidence

“Human-Led Continuous Testing.”

Source: RevenueBase Database · checked Sep 28, 2026
8Indirect evidenceManchester, United KingdomHQ checked Sep 28, 202611-5036 contacts →

Indirect evidence

“Secarma exists to keep the world safe.”

Source: RevenueBase Database · checked Sep 28, 2026
9Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5036 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
10Indirect evidenceCambridge, United KingdomHQ checked Sep 28, 202611-5034 contacts →

Indirect evidence

“Pentesting Exams by Pentesting Experts.”

Source: RevenueBase Database · checked Sep 28, 2026
11Partial evidenceLondon, United KingdomHQ checked Sep 28, 20261,001-5,00033 contacts →

Partial evidence

“NotSoSecure Training, part of Claranet Cyber Security.”

Source: RevenueBase Database · checked Sep 28, 2026
12Partial evidenceBirmingham, United KingdomHQ checked Sep 28, 202611-5032 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
13Partial evidenceLancaster, United KingdomHQ checked Sep 28, 202611-5030 contacts →

Partial evidence

“Cyber security can feel overwhelming.”

Source: RevenueBase Database · checked Sep 28, 2026
14Indirect evidencePortsmouth, United KingdomHQ checked Sep 28, 202611-5029 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
15Partial evidenceAltrincham, United KingdomHQ checked Sep 28, 202611-5026 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 28, 2026
16Strong evidenceCheltenham, United KingdomHQ checked Sep 28, 202611-5025 contacts →

Strong evidence

“At CyberWhiz, we build next-generation IoT Cyber Security solutions across the three pillars of IoT, which are Edge·Mobile·Cloud.”

Source: RevenueBase Database · checked Sep 28, 2026
17Partial evidenceLondon, United KingdomHQ checked Sep 28, 202651-20024 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
18Strong evidenceNewbury, United KingdomHQ checked Sep 28, 202611-5023 contacts →

Strong evidence

“CyberCrowd are a market leader in the cyber security realm, offering everything from Assessment Services through to Pen Testing, CISOaaS, Certification Readiness, DPO services…”

Source: RevenueBase Database · checked Sep 28, 2026
19Indirect evidenceLondon, United KingdomHQ checked Sep 28, 202611-5023 contacts →

Indirect evidence

“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…”

Source: RevenueBase Database · checked Sep 28, 2026
20Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5020 contacts →

Partial evidence

“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…”

Source: RevenueBase Database · checked Sep 28, 2026
21Partial evidenceTunbridge Wells, United KingdomHQ checked Sep 28, 202611-5019 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 28, 2026
22Partial evidenceWimbledon, United KingdomHQ checked Sep 28, 202611-5019 contacts →

Partial evidence

“We are dedicated to advancing cyber security through meticulous assessment of products and services engineered to detect and thwart cyber attacks.”

Source: RevenueBase Database · checked Sep 28, 2026
23Indirect evidenceLeeds, United KingdomHQ checked Sep 28, 202611-5019 contacts →

Indirect evidence

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

Source: RevenueBase Database · checked Sep 28, 2026
24Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5018 contacts →

Partial evidence

“th4ts3cur1ty.company supplies cyber security services internationally.”

Source: RevenueBase Database · checked Sep 28, 2026
25Partial evidenceLondon, United KingdomHQ checked Sep 28, 202611-5017 contacts →

Partial evidence

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

Source: RevenueBase Database · checked Sep 28, 2026

Showing 25 of 245 iot security testing companies based in the United Kingdom

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Iot security testing companies based in the United Kingdom at a glance

As of Sep 28, 2026
40.0%Verified-email coverage
8.5Average contacts per company
1-10Median size (employees)
40.4%Largest-city concentration · London
Sep 28, 2026Page data refreshed

Companies by employee count

1-10
143
11-50
79
51-200
13
201-500
3
501-1,000
2
1,001-5,000
4
5,001-10,000
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 245 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 iot security testing 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 “iot security testing 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 iot security testing 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 iot security testing 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, 836 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 28, 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.

Iot security testing companies by metro

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 iot security testing 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 iot security testing companies are there based in the United Kingdom?

RevenueBase identified 245 iot security testing 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 iot security testing companies?

London leads with 99 headquartered companies, followed by Manchester (16) and Birmingham (7).

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 836 verified decision-maker contacts tracked across these 245 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 28, 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.