Company lists · Data refreshed September 2026
Top 25 Critical infrastructure security companies based in London, United Kingdom
RevenueBase identified 304 company matches for critical infrastructure security companies associated with London, United Kingdom as of September 2026 and tracks 5,643 professional contacts across them, including 1,031 with verified work emails. Across the United Kingdom, London is the largest hub for this category.
This list covers company matches for critical infrastructure security companies associated with London, 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 September 27, 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.
The 25 largest critical infrastructure security companies based in London, United Kingdom
Ranked by team size| # | Company | Contacts | |||
|---|---|---|---|---|---|
| 1 | 919 contacts → | ||||
Exact match “CIS Security is an independent security company equipped to help customers to solve the complex challenges in today’s digital, connected and regulated business world.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 2 | 242 contacts → | ||||
Exact match “Obrela Security Industries is a global provider of cyber security services.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 3 | 137 contacts → | ||||
Exact match “The Keyholding Company are a tech-enabled mobile security services company, specialising in alarm response, mobile patrols, locks and unlocks, emergency and temporary guarding…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 4 | 105 contacts → | ||||
Exact match “Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 5 | 87 contacts → | ||||
Exact match “ITC Secure is an advisory-led cyber security services company.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 6 | 85 contacts → | ||||
Exact match “At Servoca Secure Solutions, we take great pride in delivering a multi-service security business; offering a range of complementary products and services to both the public and…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 7 | 64 contacts → | ||||
Exact match “City Security Services (CSS) have more than 25 years’ experience within the corporate security, public sector, education and social housing markets delivering manned guarding…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 8 | 58 contacts → | ||||
Exact match “Black Diamond Security - Safeguarding Your World.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 9 | 52 contacts → | ||||
Exact match “CyberOwl helps asset operators in the maritime and critical national infrastructure sectors gain visibility, cyber security and cyber compliance of systems on their distributed…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 10 | 52 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 · Sep 27, 2026 · View company records in RevenueBase | |||||
| 11 | 51 contacts → | ||||
Exact match “Established in Custom Intelligent Security is a technology driven ISO27001 & NSi Gold Accredited independent electronic security specialist with a proven track record of…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 12 | 49 contacts → | ||||
Exact match “GSA Global helps organisations, families and individuals respond to serious, complex and emerging security risks.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 13 | 49 contacts → | ||||
Exact match “Electranet’s mission is to be a preferred partner to the public and private sectors, bringing competitively priced, secure and innovative solutions to the market.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 14 | 48 contacts → | ||||
Exact match “In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 15 | 44 contacts → | ||||
Exact match “CornerStone is an award winning, independent, security and digital building consulting firm with headquarters in the UK.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 16 | 43 contacts → | ||||
Exact match “AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 17 | 39 contacts → | ||||
Exact match “Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 18 | 34 contacts → | ||||
Exact match “Our elite teams offer bespoke, integrated security solutions that adapt and react to the evolving threat landscape.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 19 | 30 contacts → | ||||
Exact match “Capstar provides technology-enabled threat, risk and security services to private and corporate clients.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 20 | 29 contacts → | ||||
Exact match “Cyber security is the modern business' greatest risk.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 21 | 28 contacts → | ||||
Exact match “Priavo Security Group is an established provider of comprehensive security risk management, dedicated to safeguarding individuals, information, assets, and reputation through…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 22 | 21 contacts → | ||||
Exact match “Templar Executives is an award winning, international Cyber Security advisory services and solutions company operating at the highest levels across the public and private sectors.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 23 | 20 contacts → | ||||
Exact match “LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 24 | 20 contacts → | ||||
Exact match “Cyber Energia – Your Comprehensive Cyber Security Solution for a smart & sustainable energy market Cyber Energia is a dynamic managed security service provider offering OT / SCADA…” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
| 25 | 20 contacts → | ||||
Exact match “Formed in 2018, NGS (UK) Ltd are independent, Next Generation Security trusted advisors, providing all-encompassing solutions from the perimeter to the endpoint.” Recorded in the RevenueBase company graph · Sep 27, 2026 · View company records in RevenueBase | |||||
RevenueBase SmartSearch
Describe a niche business in your own words. RevenueBase SmartSearch compares the meaning of your description with company business descriptions compiled in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit.
This list uses Exact for “critical infrastructure security companies”. Each Exact match badge shows membership in that saved search; it is not an individual similarity score or a service-quality rating. Recorded descriptions are shown where available.
Showing 25 of 304 critical infrastructure security companies based in London, United Kingdom
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Critical infrastructure security companies based in London, United Kingdom at a glance
As of Sep 27, 2026Companies by employee count
Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 304 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 London, United Kingdom whose business descriptions match “critical infrastructure 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 1,031 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 September 27, 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.
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 “critical infrastructure security companies”; each Exact match badge shows search membership, not an individual similarity or quality score.
How many critical infrastructure security companies are there based in London, United Kingdom?
RevenueBase identified 304 company matches for critical infrastructure security companies associated with London, United Kingdom as of September 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?
CIS Security Limited tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.
Which city in the United Kingdom has the most critical infrastructure security companies?
London leads the United Kingdom with 304 company records, followed by Manchester (26) and Birmingham (24).
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 1,031 professional contacts with verified work emails tracked across these 304 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 September 27, 2026.
Ready to reach these companies? Verified emails and direct dials for all 304 critical infrastructure security companies based in London, United Kingdom. Start with a free account, no credit card.
Download this list →Related lists
Critical infrastructure security companies by geography
- Critical infrastructure security companies based in Brisbane, Australia
- Critical infrastructure security companies based in Canberra, Australia
- Critical infrastructure security companies based in Melbourne, Australia
- Critical infrastructure security companies based in Perth, Australia
- Critical infrastructure security companies based in Sydney, Australia
- Critical infrastructure security companies based in Rio De Janeiro, Brazil
- Critical infrastructure security companies based in Sao Paulo, Brazil
- Critical infrastructure security companies based in Calgary, Canada
- Critical infrastructure security companies based in Montreal, Canada
- Critical infrastructure security companies based in Ottawa, Canada
- Critical infrastructure security companies based in Toronto, Canada
- Critical infrastructure security companies based in Santiago, Chile
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.
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Critical infrastructure security companies based in Brisbane, Australia
- Critical infrastructure security companies based in Canberra, Australia
- Critical infrastructure security companies based in Melbourne, Australia
- Critical infrastructure security companies based in Perth, Australia
- Critical infrastructure security companies based in Sydney, Australia
- Critical infrastructure security companies based in Rio De Janeiro, Brazil
Company intelligence · public preview
Top 25 critical infrastructure security companies based in London, United Kingdom
Find companies in any niche.
Describe the businesses you want in your own words. RevenueBase SmartSearch matches company descriptions by meaning.
RevenueBase records 304 matching company records for critical infrastructure security companies based in London, United Kingdom, with 5,643 tracked contacts and 1,031 verified work emails.
This public preview shows 25 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: September 27, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 25 critical infrastructure security companies based in London, United Kingdom
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 |  CIS Security Limitedcis-security.co.ukHQ: London, United KingdomReported employees: 1,001-5,000 | London, United Kingdom | 1,001-5,000 | Exact match | 919 contacts → |
“CIS Security is an independent security company equipped to help customers to solve the complex challenges in today’s digital, connected and regulated business world.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 |  Obrelaobrela.comHQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 242 contacts → |
“Obrela Security Industries is a global provider of cyber security services.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 |  The Keyholding Companykeyholding.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 137 contacts → |
“The Keyholding Company are a tech-enabled mobile security services company, specialising in alarm response, mobile patrols, locks and unlocks, emergency and temporary guarding…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 |  Conoscoconosco.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 105 contacts → |
“Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 |  ITC Secureitcsecure.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 87 contacts → |
“ITC Secure is an advisory-led cyber security services company.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 |  Servoca Secure Solutions Limitedservoca-secure.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 85 contacts → |
“At Servoca Secure Solutions, we take great pride in delivering a multi-service security business; offering a range of complementary products and services to both the public and…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 |  City Security Services Part Of City Group Securitycitysecurity.org.ukHQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 64 contacts → |
“City Security Services (CSS) have more than 25 years’ experience within the corporate security, public sector, education and social housing markets delivering manned guarding…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 |  Black Diamond Securityblackdiamondsecurity.co.ukHQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 58 contacts → |
“Black Diamond Security - Safeguarding Your World.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 |  Cyberowlcyberowl.ioHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“CyberOwl helps asset operators in the maritime and critical national infrastructure sectors gain visibility, cyber security and cyber compliance of systems on their distributed…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 |  Hexegichexegic.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“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 description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 |  Custom Intelligent Securitycustomsecurity.tvHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 51 contacts → |
“Established in Custom Intelligent Security is a technology driven ISO27001 & NSi Gold Accredited independent electronic security specialist with a proven track record of…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 |  GSA Globalgsaglobal.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 49 contacts → |
“GSA Global helps organisations, families and individuals respond to serious, complex and emerging security risks.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 |  Electranet UK Limitedelectranetuk.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 49 contacts → |
“Electranet’s mission is to be a preferred partner to the public and private sectors, bringing competitively priced, secure and innovative solutions to the market.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 |  Frankton Group LTDfranktongroup.comHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 48 contacts → |
“In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 |  Cornerstonecornerstonegrg.co.ukHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 44 contacts → |
“CornerStone is an award winning, independent, security and digital building consulting firm with headquarters in the UK.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 |  Ak9 Security And FM Solutions LTDak9security.comHQ: London, United KingdomReported employees: 501-1,000 | London, United Kingdom | 501-1,000 | Exact match | 43 contacts → |
“AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 | HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 39 contacts → |
“Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 |  Team Fusion LTDteamfusion.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 34 contacts → |
“Our elite teams offer bespoke, integrated security solutions that adapt and react to the evolving threat landscape.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 |  Capstarcapstar.coHQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 30 contacts → |
“Capstar provides technology-enabled threat, risk and security services to private and corporate clients.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 |  J2 Msspj2mssp.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 29 contacts → |
“Cyber security is the modern business' greatest risk.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 |  Priavo Securitypriavosecurity.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 28 contacts → |
“Priavo Security Group is an established provider of comprehensive security risk management, dedicated to safeguarding individuals, information, assets, and reputation through…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 | Templar Executivestemplarexecs.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 21 contacts → |
“Templar Executives is an award winning, international Cyber Security advisory services and solutions company operating at the highest levels across the public and private sectors.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 | LMS Securitylmssecurity.co.uk HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 | Cyber Energiacyberenergia.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“Cyber Energia – Your Comprehensive Cyber Security Solution for a smart & sustainable energy market Cyber Energia is a dynamic managed security service provider offering OT / SCADA…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 25 |  NGS Next Generation Securityngsuk.comHQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“Formed in 2018, NGS (UK) Ltd are independent, Next Generation Security trusted advisors, providing all-encompassing solutions from the perimeter to the endpoint.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 25 of 304 company matches
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Critical infrastructure security companies: dataset insights
September 27, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
304 records in the displayed employee bands.
0 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 304 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: September 27, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Questions about this company list
What does Exact match mean for critical infrastructure security companies?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many critical infrastructure security companies did RevenueBase find based in London, United Kingdom?
The saved snapshot records 304 matching company records, 5,643 tracked contacts and 1,031 verified emails. The public preview displays 25 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: September 27, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
Critical infrastructure security companies by geography
- Critical infrastructure security companies based in Brisbane, Australia
- Critical infrastructure security companies based in Canberra, Australia
- Critical infrastructure security companies based in Melbourne, Australia
- Critical infrastructure security companies based in Perth, Australia
- Critical infrastructure security companies based in Sydney, Australia
- Critical infrastructure security companies based in Rio De Janeiro, Brazil
- Critical infrastructure security companies based in Sao Paulo, Brazil
- Critical infrastructure security companies based in Calgary, Canada
- Critical infrastructure security companies based in Montreal, Canada
- Critical infrastructure security companies based in Ottawa, Canada
- Critical infrastructure security companies based in Toronto, Canada
- Critical infrastructure security companies based in Santiago, Chile
Cite this list
RevenueBase Data Team. Top 25 critical infrastructure security companies based in London, United Kingdom. Snapshot: September 27, 2026. https://revenuebase.ai/companies/critical-infrastructure-security-companies/united-kingdom/london.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
More company lists
- All company lists
- Lists by location
- Lists A-Z
- New lists
- Critical infrastructure security companies based in Brisbane, Australia
- Critical infrastructure security companies based in Canberra, Australia
- Critical infrastructure security companies based in Melbourne, Australia
- Critical infrastructure security companies based in Perth, Australia
- Critical infrastructure security companies based in Sydney, Australia
- Critical infrastructure security companies based in Rio De Janeiro, Brazil
Company intelligence · public preview
Top 25 critical infrastructure security companies based in London, United Kingdom
RevenueBase records 304 matching company records for critical infrastructure security companies based in London, United Kingdom, with 5,643 tracked contacts and 1,031 verified work emails.
This public preview shows 25 selected records ordered by tracked contacts. RevenueBase SmartSearch finds company descriptions that match by meaning at Exact. Snapshot: September 27, 2026.
RevenueBase compiles business descriptions for niche-company discovery; each row shows a recorded excerpt where available. Adapt this search to find the companies and contacts you want.
Top 25 critical infrastructure security companies based in London, United Kingdom
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
| # | Company | Headquarters on record | Reported employees | RevenueBase SmartSearch | Tracked contacts |
|---|---|---|---|---|---|
| 1 | CIS Security Limitedcis-security.co.uk HQ: London, United KingdomReported employees: 1,001-5,000 | London, United Kingdom | 1,001-5,000 | Exact match | 919 contacts → |
“CIS Security is an independent security company equipped to help customers to solve the complex challenges in today’s digital, connected and regulated business world.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 2 | Obrelaobrela.com HQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 242 contacts → |
“Obrela Security Industries is a global provider of cyber security services.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 3 | The Keyholding Companykeyholding.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 137 contacts → |
“The Keyholding Company are a tech-enabled mobile security services company, specialising in alarm response, mobile patrols, locks and unlocks, emergency and temporary guarding…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 4 | Conoscoconosco.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 105 contacts → |
“Cybersecurity specialists providing technology and telecoms solutions that gives you the leadership, experience and resilience you need to build and secure the future of work.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 5 | ITC Secureitcsecure.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 87 contacts → |
“ITC Secure is an advisory-led cyber security services company.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 6 | Servoca Secure Solutions Limitedservoca-secure.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 85 contacts → |
“At Servoca Secure Solutions, we take great pride in delivering a multi-service security business; offering a range of complementary products and services to both the public and…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 7 | City Security Services Part Of City Group Securitycitysecurity.org.uk HQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 64 contacts → |
“City Security Services (CSS) have more than 25 years’ experience within the corporate security, public sector, education and social housing markets delivering manned guarding…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 8 | Black Diamond Securityblackdiamondsecurity.co.uk HQ: London, United KingdomReported employees: 201-500 | London, United Kingdom | 201-500 | Exact match | 58 contacts → |
“Black Diamond Security - Safeguarding Your World.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 9 | Cyberowlcyberowl.io HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“CyberOwl helps asset operators in the maritime and critical national infrastructure sectors gain visibility, cyber security and cyber compliance of systems on their distributed…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 10 | Hexegichexegic.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 52 contacts → |
“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 description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 11 | Custom Intelligent Securitycustomsecurity.tv HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 51 contacts → |
“Established in Custom Intelligent Security is a technology driven ISO27001 & NSi Gold Accredited independent electronic security specialist with a proven track record of…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 12 | GSA Globalgsaglobal.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 49 contacts → |
“GSA Global helps organisations, families and individuals respond to serious, complex and emerging security risks.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 13 | Electranet UK Limitedelectranetuk.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 49 contacts → |
“Electranet’s mission is to be a preferred partner to the public and private sectors, bringing competitively priced, secure and innovative solutions to the market.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 14 | Frankton Group LTDfranktongroup.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 48 contacts → |
“In today’s complex threat environment, businesses, individuals, and organisations require trusted partners to provide the ultimate assurance that their assets are well protected.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 15 | Cornerstonecornerstonegrg.co.uk HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 44 contacts → |
“CornerStone is an award winning, independent, security and digital building consulting firm with headquarters in the UK.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 16 | Ak9 Security And FM Solutions LTDak9security.com HQ: London, United KingdomReported employees: 501-1,000 | London, United Kingdom | 501-1,000 | Exact match | 43 contacts → |
“AK9 Security and FM Solutions offers comprehensive security solutions for businesses, governmental organizations, and residential areas.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 17 | HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 39 contacts → |
“Gratte Brothers is an experienced provider of integrated security solutions, which are Built on Strong Values and ultimately deliver a measurable return on investment.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 18 | Team Fusion LTDteamfusion.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 34 contacts → |
“Our elite teams offer bespoke, integrated security solutions that adapt and react to the evolving threat landscape.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 19 | Capstarcapstar.co HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 30 contacts → |
“Capstar provides technology-enabled threat, risk and security services to private and corporate clients.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 20 | J2 Msspj2mssp.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 29 contacts → |
“Cyber security is the modern business' greatest risk.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 21 | Priavo Securitypriavosecurity.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 28 contacts → |
“Priavo Security Group is an established provider of comprehensive security risk management, dedicated to safeguarding individuals, information, assets, and reputation through…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 22 | Templar Executivestemplarexecs.com HQ: London, United KingdomReported employees: 51-200 | London, United Kingdom | 51-200 | Exact match | 21 contacts → |
“Templar Executives is an award winning, international Cyber Security advisory services and solutions company operating at the highest levels across the public and private sectors.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 23 | LMS Securitylmssecurity.co.uk HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“LMS Security are a fully Independent, privately owned, Internationally recognised and accredited Security Consultancy; owned and built by Electronic and Physical Security…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 24 | Cyber Energiacyberenergia.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“Cyber Energia – Your Comprehensive Cyber Security Solution for a smart & sustainable energy market Cyber Energia is a dynamic managed security service provider offering OT / SCADA…” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
| 25 | NGS Next Generation Securityngsuk.com HQ: London, United KingdomReported employees: 11-50 | London, United Kingdom | 11-50 | Exact match | 20 contacts → |
“Formed in 2018, NGS (UK) Ltd are independent, Next Generation Security trusted advisors, providing all-encompassing solutions from the perimeter to the endpoint.” Recorded description excerpt · September 27, 2026Open company data in RevenueBase ↗Free signup required. | |||||
Showing 25 of 304 company matches
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Critical infrastructure security companies: dataset insights
September 27, 2026These summaries describe recorded coverage in this saved dataset. This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Reported company sizes
304 records in the displayed employee bands.
0 matching records are outside the displayed bands or do not have a displayed size. Bars show shares of the displayed bands.
Email recency for this list is measured across the whole United Kingdom list rather than for London, so it is reported there. Company counts and contact totals on this page are exact for London, over 304 companies.
How this company list was built
Describe a niche in your own words: companies installing commercial solar, or manufacturers of sustainable packaging. RevenueBase SmartSearch finds companies whose compiled business descriptions match by meaning. This list is one saved example to adapt.
Where the company descriptions come from
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
RevenueBase SmartSearch matching settings
- Exact
- Closest fits to the business described.
- Similar
- Similar businesses with a wider range of fits.
- Related
- Related businesses in and around the category.
- Broad
- A broader set of businesses connected to the description.
RevenueBase SmartSearch · Exact match identifies inclusion in this search's closest semantic matching setting. It is not a per-company confidence score, a literal keyword match, or a quality endorsement.
Selection, ordering and scope
The public list shows selected company records with contact and verified-email coverage. Reported employee bands provide separate company-size context.
This page is derived from saved source records; per-contact mobile coverage and email-recency results are not established by this snapshot.
Recorded company descriptions support research; check company websites for current services. The selected preview is ordered by tracked contacts and is not a list of the best service providers.
Snapshot: September 27, 2026.
RevenueBase is a B2B data infrastructure company. Its September 3, 2026 published methodology describes a graph of 60 million companies and 398.9 million professional contacts; these platform figures differ from this page's totals. Published methodology ↗
Questions about this company list
What does Exact match mean for critical infrastructure security companies?
The separate RevenueBase SmartSearch column identifies inclusion at the closest semantic matching preset. It is not a literal keyword match, a per-company confidence score or a quality endorsement. Changing the search form opens a new search in RevenueBase; it does not reclassify these saved rows.
How many critical infrastructure security companies did RevenueBase find based in London, United Kingdom?
The saved snapshot records 304 matching company records, 5,643 tracked contacts and 1,031 verified emails. The public preview displays 25 selected records.
Where do the company descriptions come from?
RevenueBase compiles company information from public sources, including company websites and public professional profiles such as LinkedIn, alongside information supplied by companies. The short recorded excerpt shown here is separate from the complete business description used for matching; individual source URLs and collection dates are not provided in this public snapshot.
How are the public companies ordered?
The selected public records are ordered by contacts tracked in RevenueBase, highest first. Contact coverage is a prospecting measure, not an assessment of the company's services or quality.
How can I get contact information?
Select a company's contact count to open its filtered contacts in RevenueBase. Free signup is required and includes 500 credits and limited free results. Verified emails, direct dials and mobile numbers depend on available coverage.
How current is this list?
Snapshot: September 27, 2026. Review each company's website for current services and locations. A recorded business description does not establish that every company offers every service named in the search.
What do headquarters and employee bands mean?
These are recorded company-level fields, rather than a map of every branch or a count of specialists. Missing headquarters or employee bands are labeled; older records may show a location separately from recorded headquarters.
Build your next target company list
Adapt this niche search and work with available contacts in RevenueBase.
Related lists
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Cite this list
RevenueBase Data Team. Top 25 critical infrastructure security companies based in London, United Kingdom. Snapshot: September 27, 2026. https://revenuebase.ai/companies/critical-infrastructure-security-companies/united-kingdom/london.
This is a selected public preview of saved company records, rather than an independently verified census. Open the source page ↗
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