Company lists · Data refreshed September 2026

Top 25 Infrastructure hardening contractors based in the United Kingdom

Name: Infrastructure hardening contractors based in the United Kingdom
Creator: RevenueBase
License: https://creativecommons.org/licenses/by/4.0/

Compiled by the RevenueBase Data Team Data refreshed Sep 17, 2026 191 companies tracked

RevenueBase identified 191 infrastructure hardening contractors headquartered in the United Kingdom as of September 2026 and tracks 1,110 professional contacts across them, including 275 with verified work emails. London is the largest hub.

This list covers infrastructure hardening contractors 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 17, 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 17, 2026 86% judged on-target in blind review

191Companies

1,110Contacts tracked

275Verified emails

Explore this list → Free signup · no credit card · 500 free credits

The 25 largest infrastructure hardening contractors based in the United Kingdom

Ranked by team size

Top 25 of 191 infrastructure hardening contractors based in the United Kingdom, ranked by team size, largest first. Data refreshed Sep 17, 2026. RevenueBase Smart Search rates how each company's information relates to infrastructure hardening contractors: 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	Synoptix	Indirect evidence	Bristol, United KingdomHQ checked Sep 17, 2026	51-200	75 contacts →
	Indirect evidence “Synoptix was formed in 2011 to provide engineering solutions across various technical industries.” Source: RevenueBase Database · checked Sep 17, 2026
2	Black Diamond Security	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	201-500	58 contacts →
	Indirect evidence “Black Diamond Security - Safeguarding Your World.” Source: RevenueBase Database · checked Sep 17, 2026
3	SQR Group Security Solutions LTD	Partial evidence	Barnet, United KingdomHQ checked Sep 17, 2026	501-1,000	58 contacts →
	Partial evidence “In today’s advanced, interconnected world, protecting the infrastructure that allows society to function is crucial.” Source: RevenueBase Database · checked Sep 17, 2026
4	Cyberlab	Indirect evidence	Alderley Edge, United KingdomHQ checked Sep 17, 2026	51-200	57 contacts →
	Indirect evidence “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…” Source: RevenueBase Database · checked Sep 17, 2026
5	Omerta	Indirect evidence	Saffron Walden, United KingdomHQ checked Sep 17, 2026	51-200	38 contacts →
	Indirect evidence “Omerta - A Global Security Technology and Services Company.” Source: RevenueBase Database · checked Sep 17, 2026
6	Barrier Networks	Indirect evidence	Glasgow, United KingdomHQ checked Sep 17, 2026	11-50	34 contacts →
	Indirect evidence “We are your strategic cybersecurity partner – going beyond traditional models to deliver agile, expert-led protection tailored to the needs of regulated industries and critical…” Source: RevenueBase Database · checked Sep 17, 2026
7	Cyber Security Specialists	Indirect evidence	Altrincham, United KingdomHQ checked Sep 17, 2026	11-50	26 contacts →
	Indirect 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 17, 2026
8	Secure Construct	Partial evidence	Chichester, United KingdomHQ checked Sep 17, 2026	11-50	24 contacts →
	Partial evidence “We deliver buildings and infrastructure for clients whom the protection of their estate and assets are a priority.” Source: RevenueBase Database · checked Sep 17, 2026
9	Hamiltonian Dynamics	Indirect evidence	Gloucestershire, United KingdomHQ checked Sep 17, 2026	11-50	23 contacts →
	Indirect evidence “At Hamiltonian Dynamics we have a secure by design engineering mindset built into the core of our company.” Source: RevenueBase Database · checked Sep 17, 2026
10	Anotherday	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	11-50	21 contacts →
	Indirect evidence “AnotherDay is a new kind of defence & security consulting firm established to bring the power of effective intelligence and strategy to the challenge of safeguarding individuals…” Source: RevenueBase Database · checked Sep 17, 2026
11	LMS Security	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	11-50	20 contacts →
	Indirect 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 17, 2026
12	NGS Next Generation Security	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	11-50	20 contacts →
	Indirect evidence “Formed in 2018, NGS (UK) Ltd are independent, Next Generation Security trusted advisors, providing all-encompassing solutions from the perimeter to the endpoint.” Source: RevenueBase Database · checked Sep 17, 2026
13	DEV Null Security	Indirect evidence	Edinburgh, United KingdomHQ checked Sep 17, 2026	11-50	17 contacts →
	Indirect evidence “We are a cyber security consultancy that specialises in security solution architecture, engineering, implementation and operational support.” Source: RevenueBase Database · checked Sep 17, 2026
14	PDP Projects	Indirect evidence	Peterborough, United KingdomHQ checked Sep 17, 2026	11-50	12 contacts →
	Indirect evidence “PDP offers a unique blend of security solutions, covering all aspects of human, physical and cyber security, which are designed to meet the specific needs of clients in both…” Source: RevenueBase Database · checked Sep 17, 2026
15	Parfas Group	Indirect evidence	Oldham, United KingdomHQ checked Sep 17, 2026	11-50	10 contacts →
	Indirect evidence “PARFAS utilise the latest thinking and technology to create and install security systems that are commensurate with current and emerging risks.” Source: RevenueBase Database · checked Sep 17, 2026
16	Icyberdefence	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	11-50	8 contacts →
	Indirect evidence “iCyberDefence is a boutique cybersecurity services firm that offers a wide range of security consulting and security engineering services with the necessary products and tools.” Source: RevenueBase Database · checked Sep 17, 2026
17	Stratia Cyber	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	11-50	8 contacts →
	Indirect 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 17, 2026
18	Chubb Systems Limited	Partial evidence	Blackburn, United KingdomHQ checked Sep 17, 2026	501-1,000	8 contacts →
	Partial evidence “Chubb Systems is one of the leading designers and integrators of security systems identifying and solving complex requirements to critical national infrastructure and large scale…” Source: RevenueBase Database · checked Sep 17, 2026
19	Kelltron Consulting Services	Indirect evidence	Aylesbury, United KingdomHQ checked Sep 17, 2026	11-50	7 contacts →
	Indirect 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 17, 2026
20	Klaatu IT Security LTD	Indirect evidence	Swindon, United KingdomHQ checked Sep 17, 2026	1-10	7 contacts →
	Indirect evidence “Klaatu IT Security is an IT security consultancy and developer.” Source: RevenueBase Database · checked Sep 17, 2026
21	Blue Nine	Indirect evidence	Salisbury, United KingdomHQ checked Sep 17, 2026	11-50	7 contacts →
	Indirect evidence “Established in 2006, Blue Nine is a trusted security solutions provider, serving government entities, commercial organisations, and private clients.” Source: RevenueBase Database · checked Sep 17, 2026
22	Securenet Communication Solutions	Indirect evidence	Royston, United KingdomHQ checked Sep 17, 2026	1-10	6 contacts →
	Indirect evidence “We design secure solutions that help to protect your business.” Source: RevenueBase Database · checked Sep 17, 2026
23	FALX	Indirect evidence	York, United KingdomHQ checked Sep 17, 2026	1-10	5 contacts →
	Indirect evidence “Falx is a consultancy based in England, delivering both technology and cyber security advisory services to organisations worldwide.” Source: RevenueBase Database · checked Sep 17, 2026
24	White Coast Security	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	51-200	5 contacts →
	Indirect evidence “We Empower Organizations Worldwide with Cutting-Edge Security Solutions.” Source: RevenueBase Database · checked Sep 17, 2026
25	Westlands Advisory	Indirect evidence	London, United KingdomHQ checked Sep 17, 2026	1-10	4 contacts →
	Indirect evidence “Westlands Advisory (WA) works exclusively on security market issues, helping industry, government and security professionals to minimise business risk and improve performance…” Source: RevenueBase Database · checked Sep 17, 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: infrastructure hardening contractors. 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 infrastructure hardening contractors.
Partial evidence: Its own public description names part of infrastructure hardening contractors, so it works in or next to the category without describing itself that way.
Indirect evidence: The description shown does not name infrastructure hardening contractors. 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 191 infrastructure hardening contractors based in the United Kingdom

See the full list, filter by size, metro and specialty, and get verified emails and direct dials for all 275 reachable decision-makers.

Free signup · no credit card

View the full list →

Infrastructure hardening contractors based in the United Kingdom at a glance

As of Sep 17, 2026

24.8%Verified-email coverage

5.8Average contacts per company

1-10Median size (employees)

35.1%Largest-city concentration · London

Sep 17, 2026Page data refreshed

Companies by employee count

1-10

126

11-50

51-200

201-500

501-1,000

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 191 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 infrastructure hardening contractors, 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 “infrastructure hardening contractors”. 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 infrastructure hardening contractors), 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 infrastructure hardening contractors, 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, 275 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 17, 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.

Infrastructure hardening contractors by metro

Infrastructure hardening contractors in London67

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 infrastructure hardening contractors, 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 infrastructure hardening contractors are there based in the United Kingdom?

RevenueBase identified 191 infrastructure hardening contractors 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?

Synoptix, headquartered in Bristol, tops this list with the largest team on record.

Which city has the most infrastructure hardening contractors?

London leads with 67 headquartered companies, followed by Bristol (4) and Manchester (4).

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 275 verified decision-maker contacts tracked across these 191 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 17, 2026.

Ready to reach these companies? Verified emails and direct dials for all 191 infrastructure hardening contractors based in the United Kingdom. Start with a free account, no credit card.

Download this list →

Related lists

Infrastructure hardening contractors by geography

Browse the directory

Browse: Companies home · All United Kingdom lists · All Infrastructure hardening contractors lists · New lists

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.