Home / Certifications / ISO 27001

Find a pentest company with ISO 27001

1560 companies have this certification

Sentrium Security

Sentrium Security

Advanced Penetration Testing
Cheltenham, United Kingdom 7 employees

UK-based cybersecurity consultancy founded in 2018; 4 employees with 16.7% YoY growth; CREST-approved provider specializing in application, cloud, and penetration testing services, offering comprehensive vulnerability assessments and risk reduction.

Penetration Testing
Vulnerability Assessment
Cyber Security Advisory Services
Pentest Limited

Pentest Limited

Web Application Penetration Te...
Altrincham, United Kingdom 31 employees

Cybersecurity company specializing in penetration testing, red teaming, and consultancy services; 21 employees, $9.7M annual revenue, founded 2001 in Altrincham, UK; offers tailored testing, compliance, workshops, and research activities, with a global web rank of #3,838,798 and 4,379 monthly visits.

Penetration Testing (web
Mobile
Infrastructure
+4 more
Pen Test Partners

Pen Test Partners

Web Application Pentesting
Buckingham, United Kingdom 110 employees

Cybersecurity company specializing in penetration testing services across networks, applications, and cloud; 67 employees, $6.1M revenue, founded 2010, based in Buckingham, UK; recognized for expertise in red teaming, testing, and security consulting, with 28,414 monthly website visits and global rank #1,041,359.

Penetration Testing
Red Teaming
Attack Surface Assessment
+5 more
Razorthorn Security

Razorthorn Security

CREST Accredited Penetration T...
Tunbridge Wells, United Kingdom 17 employees

Cybersecurity consultancy specializing in penetration testing, compliance, and consulting; 14 employees with -10.5% YoY growth; CREST-accredited pentesting across infrastructure, wireless, web, and mobile; Recognized by Gartner; Founded 2007; Tunbridge Wells, UK.

Cybersecurity Consultancy
Penetration Testing
Continuous Threat Exposure Management
+2 more
Bruce & Butler

Bruce & Butler

External and Internal Penetrat...
Sheffield, United Kingdom 15 employees

Cybersecurity company specializing in penetration testing, vulnerability assessments, and audits; 8 employees with 15.4% YoY growth; founded 2015; Sheffield, UK; provides CREST-accredited penetration testing services and data protection solutions for UK and international clients.

Data Protection
Cyber Security
Penetration Testing
+2 more
Salus Cyber

Salus Cyber

CHECK Penetration Testing
United Kingdom 35 employees

Cybersecurity company based in the United Kingdom; specializes in penetration testing, incident response, data protection, and security strategy; 25 employees with 9.4% YoY growth; founded in 2017; offers comprehensive security services including ethical penetration testing and compliance testing.

Penetration Testing
Critical Response
Data Protection
+3 more
Cybercontrols.io

Cybercontrols.io

Offensive Security
Morpeth, United Kingdom 8 employees

Cybercontrols.io is a UK-based infosec consultancy providing cybersecurity and compliance services, including penetration testing, internal audits, and endpoint security; founded in 2022, with 4 employees and +300% YoY growth, headquartered in Morpeth, UK.

Compliance Consulting
Penetration Testing
Cybersecurity Strategy
+4 more
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Mollis Group

Mollis Group

Cloud and Application Penetrat...
London, United Kingdom 14 employees

UK-based IT services and consulting company founded in 2019; specializes in cloud cybersecurity, penetration testing, ethical hacking, security architecture, and digital transformation; 3 employees; headquartered in London, UK; provides professional penetration testing services as explicitly stated on their website.

Penetration Testing
Ethical Hacking
Security Consulting
+1 more
CyberCrowd

CyberCrowd

Comprehensive Penetration Test...
Newbury, United Kingdom 34 employees

CyberCrowd is a UK-based IT services and cybersecurity company founded in 2016, with 18 employees and a 30.8% YoY growth. It specializes in penetration testing, assessment services, and cyber security consulting, serving clients with comprehensive vulnerability evaluations, web and mobile app testing, and certification readiness. The firm is a market leader in cyber security assessment, with a strong web presence and active recent activity in industry news.

Penetration Testing
Cybersecurity Assessment
CISO As A Service
+4 more
RM Information Security

RM Information Security

Web Application Pentesting
Manchester, United Kingdom 6 employees

RM Information Security is a UK-based private cybersecurity consultancy specializing in penetration testing and information security. Founded in 2015 and employing 6 staff, they focus on expert, communication-driven services with active penetration testing offerings, including application security and vulnerability exploitation. They are headquartered in Manchester, UK, with a modest online presence of 1,068 monthly visits and a global rank of approximately 12.7 million.

Penetration Testing (web
Infrastructure
Mobile
+4 more
Surecloud Cyber Services

Surecloud Cyber Services

Infrastructure and Cloud Secur...
United Kingdom 28 employees

Cybersecurity company based in Gloucester, UK; specializes in penetration testing, including infrastructure and cloud security testing, with active vulnerability assessment and attack simulation capabilities.

Penetration Testing
Vulnerability Management
Managed Detection And Response
+4 more
CODA Security

CODA Security

Application and Systems Pentes...
Leamington Spa, United Kingdom 8 employees

Cybersecurity consultancy specializing in computer and network security; founded 2017, 4 employees, based in Leamington Spa, UK. Offers penetration testing, risk management, vulnerability assessment, and bespoke cybersecurity services; emphasizes high-quality, client-focused solutions and invests heavily in personnel.

Penetration Testing
Vulnerability Assessment
Risk Management
Secarma Ltd

Secarma Ltd

Web Application Pentesting
United Kingdom 23 employees

Cybersecurity company specializing in penetration testing services; based in Manchester, UK, with headquarters at 3 Archway, Birley Fields, Manchester, M15 5QJ; UK registered company number 04217114; explicitly offers penetration testing and cybersecurity assessments.

Penetration Testing
Cybersecurity Consultancy
Certification Services
+1 more
CODA Security Limited

CODA Security Limited

Application and Systems Pentes...
United Kingdom 4 employees

UK-based cybersecurity consultancy specializing in bespoke services; offers penetration testing, vulnerability assessments, and risk management with experienced principal-led teams. Headquartered in Leamington Spa, Warwickshire.

Penetration Testing
Vulnerability Assessment
Risk Management
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Mobius Consulting

Mobius Consulting

Hands-On Penetration Testing
United Kingdom 11 employees

UK-based cybersecurity company specializing in penetration testing and security assessments; listed on UK Companies House with registration numbers 13538454 and 06958601; offers comprehensive security testing including penetration testing and vulnerability scanning.

Penetration Testing
Security Testing
Information Security
+5 more
Cyber Defence Ltd

Cyber Defence Ltd

Goal-Driven Penetration Testin...
United Kingdom 5 employees

Cyber Defence Ltd is a UK-based cybersecurity firm specializing in modern security operations, threat intelligence, and penetration testing; offers goal-driven pentest services across diverse environments, supported by CREST accreditation, and operates primarily in the UK and Europe.

Managed SOC
Threat Intelligence
Penetration Testing
+3 more
Cloudpush

Cloudpush

Network and System Penetration...
London, United Kingdom 4 employees

IT services and consulting firm based in London, UK; specializes in cybersecurity, penetration testing, managed IT, and cloud solutions; 2 employees, founded 2020; provides comprehensive cybersecurity services including penetration testing, security awareness, and network security.

Managed IT Services
Cloud Solutions
Cybersecurity Including Penetration Testing
+5 more
Nextgen Cyber

Nextgen Cyber

Red Team Simulations
United Kingdom 10 employees

UK-based cybersecurity firm specializing in penetration testing, security assurance, red team simulations, and social engineering tests; located in Barnet, London, with UK registration at Companies House.

Penetration Testing
Security Assurance
Red Team Simulations
+5 more
Toro Solutions

Toro Solutions

Red Team Penetration Testing
Other 21 employees

UK-based security and investigations company founded in 2015, with 13 employees and a focus on cyber, physical, and personnel security. Known for creating the UK's first Red Team penetration test, it provides active penetration testing, cyber attack simulation, and security consultancy services, serving government and business clients globally.

Managed Security And Consultancy Services Including Red Team Penetration Testing
Cyber Security
Physical Security
+2 more
3ct Security

3ct Security

Comprehensive Penetration Test...
United Kingdom 5 employees

UK-based cybersecurity firm specializing in penetration testing services; headquartered in Malvern, Worcestershire, with verified operations in the UK. Provides security assessments including vulnerability management and maturity evaluations.

Penetration Testing
Vulnerability Management
Cyber Maturity Reviews
+3 more
NormCyber

NormCyber

CREST-Certified Penetration Te...
United Kingdom 72 employees

UK-based cybersecurity firm specializing in CREST-certified penetration testing services; offers active vulnerability identification and remediation through authorized cyber-attack simulations; headquartered in Fareham, England, with a registered office at 8 Barnes Wallis Road.

Penetration Testing
Managed Detection And Response
Incident Response
+5 more
Bulletproof (Cyber Security)

Bulletproof (Cyber Security)

CREST & OSCP Penetration Testi...
Other 121 employees

UK-based private cybersecurity firm with 96 employees (+0.8% YoY growth), $3.0M annual revenue; specializes in penetration testing, data protection, and compliance services; registered at 20 Grosvenor Place, London, and based in Stevenage, Hertfordshire; ranks #1,574,985 globally and #154,108 in the UK; active in cybersecurity & compliance categories including ISO 27001, SOC 2, GDPR, and red team assessments.

Penetration Testing
Cyber Security Training
Compliance Consultancy
+4 more
𝐍𝐞𝐭𝐟𝐨𝐫𝐭𝐞 𝐂𝐨𝐧𝐬𝐮𝐥𝐭𝐢𝐧𝐠 𝐋𝐭𝐝

𝐍𝐞𝐭𝐟𝐨𝐫𝐭𝐞 𝐂𝐨𝐧𝐬𝐮𝐥𝐭𝐢𝐧𝐠 𝐋𝐭𝐝

Advanced Penetration Testing
London, United Kingdom 2 employees

Cybersecurity solutions company specializing in advanced penetration testing services; based in London, UK, founded in 2023, with 2 employees and 100% YoY growth. Focuses on safeguarding digital assets and fortifying defenses against cyber threats.

Penetration Testing
Cybersecurity Audits
ISO 9001/27001/42001 Implementation
+3 more
Talion Cyber Security

Talion Cyber Security

Consultant-Led Penetration Tes...
camberley, United Kingdom 94 employees

Cybersecurity company specializing in hybrid cybersecurity services and penetration testing; 94 employees with 3.3% YoY growth; founded in 2020; based in Camberley, UK. Known for providing defense-grade cybersecurity solutions and explicit penetration testing services, with a focus on identifying vulnerabilities through simulated attacks.

Managed Detection & Response (mdr)
Soc-as-a-service
SIEM Optimization & XDR Alignment
+5 more
PrimoConnect: Compliance Support - Cyber Security - Pen Testing - Cloud - Networks

PrimoConnect: Compliance Support - Cyber Security - Pen Testing - Cloud - Networks

Web Application Pentesting
Other 2 employees

UK-based private IT security company founded in 2017 with 2 employees; specializes in penetration testing, cloud infrastructure, and compliance support. Offers offensive security testing, cyber awareness training, and secure cloud/network design, with explicit focus on penetration testing services and cyber security consultancy.

Penetration Testing
Cyber Security Consulting
Compliance Support
+1 more
ThreatSpike

ThreatSpike

Unlimited Penetration Testing ...
United Kingdom 68 employees

Cybersecurity company specializing in managed security services and penetration testing; offers unlimited penetration testing and system-specific assessments, with 47 employees, $10M revenue, founded in 2011, based in the UK, with $26.3M in funding.

Unlimited Penetration Testing
Fully Managed IT Services
Incident Detection And Response
+5 more
iSTORM®  Privacy - Security - Pentesting Consultancy

iSTORM® Privacy - Security - Pentesting Consultancy

Network and Application Pentes...
Stratford-upon-Avon, United Kingdom 19 employees

UK-based IT services and consulting firm specializing in privacy, security, and penetration testing; CREST-approved provider with 6 employees, founded in 2018, focusing on simplifying standards compliance and offering real-world security solutions. Maintains 1,806 monthly web visits and ranked #8,654,171 globally.

Privacy Consulting
Security Consulting
Penetration Testing
+1 more
FoxTech Cyber

FoxTech Cyber

Network Penetration Testing
United Kingdom 14 employees

Cybersecurity company based in the United Kingdom; specializes in managed cybersecurity services including vulnerability management, security monitoring, and penetration testing for SMEs. Offers a Managed SOC platform with integrated vulnerability management, security monitoring, and pen-testing; 8 employees, founded 2020, +16.7% YoY growth.

Penetration Testing
Vulnerability Management
Security Monitoring
+3 more
DigitalXRAID

DigitalXRAID

CREST Certified Penetration Te...
United Kingdom 53 employees

Cybersecurity company specializing in penetration testing and security services; provides CREST-accredited web and internal penetration testing with active attack simulation capabilities; based in the United Kingdom with 39 employees and $8.6M annual revenue.

Penetration Testing
Vulnerability Assessment
Security Operations Center (soc) Services
+5 more
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Punk Security Limited

Punk Security Limited

Web Application and Cloud Pent...
United Kingdom 6 employees

UK-based IT services and consulting company specializing in DevSecOps, cybersecurity, and cloud engineering; 6 employees, founded 2021, with a focus on penetration testing, governance support, and cloud security services.

Devsecops Consultancy
Penetration Testing
Governance Support
+4 more
Closed Door Security

Closed Door Security

Threat Led Penetration Testing
Stornoway, United Kingdom 12 employees

UK-based private cybersecurity company specializing in penetration testing, security assessments, engineering, and certification; CREST-accredited, partner of SBRC & Police Scotland, with 4 employees and 33.3% YoY growth; actively promotes penetration testing services through dedicated pages and certifications.

Penetration Testing
Threat Led Penetration Testing
Red Teaming
+3 more
Cognisys

Cognisys

Advanced Infrastructure, Appli...
Leeds, United Kingdom 86 employees

UK-based IT services and cybersecurity company specializing in penetration testing, security assessments, and compliance; 63 employees with 95.5% YoY growth; founded in 2017; CREST-accredited penetration testing services; headquartered in Leeds, UK.

Penetration Testing
Vulnerability Management
Security Compliance Acceleration
+2 more
Paul Reynolds Cyber Security

Paul Reynolds Cyber Security

Web Application and Infrastruc...
United Kingdom 3 employees

Cybersecurity firm based in Solihull, UK, with additional operations in Dubai, UAE; provides penetration testing (pentest) services including PTaaS and certified testing teams, emphasizing offensive security expertise.

Penetration Testing
Vulnerability Assessment
Risk Assessment
+5 more
Jumpsec

Jumpsec

Threat-Led Penetration Testing
United Kingdom 25 employees

UK cybersecurity firm Jumpsec Limited offers bespoke consultancy and CREST-certified penetration testing services, including application and threat-led pentests; based in London and Surrey, emphasizing technical excellence and expert-driven approaches.

Penetration Testing
Adversary Simulation
Purple Teaming
+5 more
Brigantia by Elovade

Brigantia by Elovade

Penetration Testing as a Servi...
thirsk, United Kingdom 53 employees

UK-based IT services and cybersecurity consulting company with 30 employees, founded in 1996; specializes in cybersecurity solutions, including penetration testing via Rootshell, and supports channel partners with recurring revenue growth; part of the Elovade Group, with a focus on security assessments, red team engagements, and managed services.

Cybersecurity Software Distribution
Penetration Testing
Vulnerability Management
+1 more
Prism Infosec

Prism Infosec

Penetration Testing and Red Te...
United Kingdom 28 employees

Cybersecurity firm based in Cheltenham, UK, specializing in penetration testing, red teaming, and GRC services; provides assessments, testing, and response solutions to enhance security posture.

Penetration Testing
Red Teaming
GRC
+5 more
CyPro

CyPro

CREST-Accredited Ethical Penet...
London, United Kingdom 21 employees

CyPro is a UK-based private cybersecurity firm specializing in computer and network security, with 15 employees and 16.7% YoY growth since 2022. It explicitly offers penetration testing services that simulate attacks to uncover vulnerabilities, supporting high-growth companies in scaling their security capabilities and gaining client trust.

Penetration Testing
Virtual CISO
Managed Detection And Response (mdr)
+5 more
Blackfoot Cybersecurity

Blackfoot Cybersecurity

Comprehensive Penetration Test...
Welwyn Garden City, United Kingdom 29 employees

Cybersecurity company specializing in computer and network security, penetration testing, and compliance; 15 employees with +20.8% YoY growth; founded in 2008; headquartered in Welwyn Garden City, UK; offers services including installation, gas washing, ventilation, and equipment manufacturing; active in cyber security training and risk management.

Data Protection
Governance Risk Compliance
Detection And Response
+4 more
CyberQ Group

CyberQ Group

Comprehensive Penetration Test...
Birmingham, United Kingdom 45 employees

CyberQ Group is a UK-based private cybersecurity firm specializing in cyber protection and penetration testing services; 27 employees, founded in 2017, with $6.3M in funding, providing 24/7 global support and known for a reactive, technology-driven approach to cybersecurity.

Penetration Testing
Vulnerability Assessment
Security Operations
+2 more
Dionach

Dionach

Penetration Testing and Securi...
United Kingdom 52 employees

Cybersecurity firm based in Oxford, UK, specializing in penetration testing and security assessments; CREST-accredited with a comprehensive suite of security services. Part of Nomios; founded in the UK.

Penetration Testing
Security Assessments
Compliance Consulting
+3 more
Cyber Vigilance

Cyber Vigilance

Infrastructure and Application...
United Kingdom 19 employees

Cyber Vigilance is a UK-based cybersecurity firm headquartered in Guildford, UK; specializes in penetration testing services that identify vulnerabilities in infrastructure and applications, including automated pentesting capabilities through Horizon3.ai partnership.

Managed Threat Detection
Penetration Testing
Product Implementation And Optimisation
+3 more
Kocho

Kocho

Identity and Security Penetrat...
United Kingdom 300 employees

UK-based cybersecurity firm specializing in Microsoft identity, security, and cloud solutions; offers penetration testing services and security consulting; registered in England and Wales (company number 04308824), with a London office.

Penetration Testing
Identity Management
Security Consulting
+3 more
CyberFortis Consulting

CyberFortis Consulting

Network and Application Penetr...
Other 6 employees

UK-based IT and cybersecurity consulting firm specializing in penetration testing, threat intelligence, risk assessments, and compliance services; 4 employees; founded 2019; offers explicit pentest services; serves clients across UK, EU, Australia, New Zealand, and USA.

Penetration Testing
Compliance Support
Security Auditing
+3 more
Exponential-e

Exponential-e

Accredited Penetration Testing
London, United Kingdom 694 employees

UK-based IT services and consulting company providing secure cloud, connectivity, cyber, and voice solutions; 492 employees, $255.7M revenue, founded 2002, headquartered in London. Offers penetration testing, red team testing, and website security testing, with a focus on active cybersecurity testing and exploitation simulation.

Connectivity Services
Cloud Services
Cyber Security Services Including Penetration Testing
+3 more
Reliance Cyber

Reliance Cyber

Comprehensive Penetration Test...
Waterloo, United Kingdom 76 employees

Reliance Cyber is a UK-based IT services and cybersecurity consulting company with 48 employees and $5M-$25M annual revenue; specializes in penetration testing, threat intelligence, incident response, and managed security services, with a focus on safeguarding organizations in the digital landscape.

Penetration Testing
Managed Infrastructure Services
Cyber Engineering
+5 more
Closed Door Security

Closed Door Security

Threat Led Penetration Testing
United Kingdom 15 employees

UK-based cybersecurity firm specializing in penetration testing and security assessments; registered in the UK (SC585645), headquartered in Stornoway, UK; offers professional pentest services as highlighted on their website and supported by external sources.

Penetration Testing
Threat Led Penetration Testing
Red Teaming
+3 more
Pentest Limited

Pentest Limited

Web Application Penetration Te...
United Kingdom 50 employees

UK-based cybersecurity company founded in 2019; registered at 22 Great James Street, London, with company number 11925182; provides manual penetration testing, red teaming, and security consultancy services.

Manual Penetration Testing
Red Teaming
Security Consultancy
+2 more
4N6

4N6

Comprehensive Penetration Test...
London, United Kingdom 15 employees

IT services and consulting company specializing in cybersecurity, troubleshooting, diagnostics, post-incident reviews, and digital forensics; offers full penetration testing services including active exploitation, vulnerability analysis, and remediation; based in London, UK with 1 employee, 1,122 monthly website visits, and ranked #11,322,919 globally.

Cybersecurity
Penetration Testing
Advanced Diagnostics And Troubleshooting
+2 more
BSI Cyber Consulting

BSI Cyber Consulting

CREST Penetration Testing and ...
cambridge, United Kingdom 59 employees

Cybersecurity company specializing in penetration testing, red team assessments, and information security services; supports CREST-certified pentest offerings and detailed testing procedures; 2 employees, $9.44M revenue, headquartered in Cambridge, UK.

Penetration Testing
Cyber Security Consultancy
Compliance Management
+2 more
Boxxe

Boxxe

Penetration Testing Services
United Kingdom 211 employees

UK-based IT solutions provider specializing in hardware, software, managed IT services, and cybersecurity; explicitly offers penetration testing (pentest) services as part of its cybersecurity portfolio; registered in England and Wales with a York headquarters.

Hardware
Software
Managed IT Services
+5 more
Securious - Data and Cyber Security

Securious - Data and Cyber Security

PCI DSS Penetration Testing
Exeter, United Kingdom 13 employees

Cybersecurity compliance and pentesting company based in Exeter, UK; 11 employees with 18.2% YoY growth; founded in 2007; provides PCI DSS, ISO 27001, Cyber Essentials, and penetration testing services to UK and international clients.

Penetration Testing
PCI DSS Compliance
ISO 27001 Certification
+2 more
Xpertex Ltd

Xpertex Ltd

Military-Grade Network Penetra...
Welwyn Garden City, United Kingdom 14 employees

UK-based IT services and consulting firm specializing in cybersecurity, including penetration testing and breach & attack simulation; 9 employees with -6.7% YoY growth; founded 2006; headquartered in Welwyn Garden City, England; active in security assessments, vulnerability analysis, and machine parts manufacturing.

Cyber Security Consulting
Penetration Testing
Breach And Attack Simulation
+3 more
Zepko

Zepko

Comprehensive IT Environment P...
United Kingdom 9 employees

Cybersecurity firm based in Guildford, United Kingdom, specializing in penetration testing; offers detailed security assessments using standardized testing methodologies and emphasizes human intervention to enhance resilience.

Managed Security Services (soc)
Penetration Testing
Security Assessments
+2 more
Cybergen® Security

Cybergen® Security

CREST Accredited Penetration T...
Oxford, United Kingdom 2 employees

Cybergen® Security is a UK-based IT services and cybersecurity consulting firm founded in 2023, with a focus on penetration testing, red teaming, and threat mitigation. The company provides CREST-accredited penetration testing and 24/7 managed detection and response, emphasizing proactive security testing and vulnerability identification, despite having only 1 employee.

Penetration Testing
Vulnerability Assessment
Compliance Consultancy (iso27001
+5 more
Protection Group International

Protection Group International

CREST Certified Penetration Te...
London, United Kingdom 125 employees

Protection Group International is a UK-based security and investigations firm specializing in digital resilience, security consulting, and cyber security services; with 77 employees (+10.6% YoY growth), $15M annual revenue, founded in 2013 in London. PGI provides CREST-aligned penetration testing services, demonstrating formal technical standards, and serves a global client base including governments and NGOs. The company operates in multiple languages and maintains active social media engagement.

Digital Resilience
Cyber Security
Penetration Testing
+3 more
GoDefend (Cyber Security)

GoDefend (Cyber Security)

Web, Mobile, and Infrastructur...
United Kingdom 8 employees

Cybersecurity company based in the United Kingdom; specializes in data security software, penetration testing, breach detection, and compliance solutions; 5 employees, founded 2018, $3.3M funding, recent £250K investment to grow threat detection tech; competes with qingteng cloud security and sonet.io.

Penetration Testing
Continuous Threat Monitoring
Vulnerability Scanning
+1 more
ResilientX Security

ResilientX Security

Web Application and Network Pe...
London, United Kingdom 12 employees

Cybersecurity company specializing in penetration testing, attack surface management, and third-party risk solutions; provides active testing and simulated attack services with a focus on web, cloud, and network security; 10 employees; Founded 2022; London, UK.

Penetration Testing
Vulnerability Assessment
Attack Surface Management
+5 more
Bridewell

Bridewell

Red Team Assessment
Reading, United Kingdom 343 employees

Cybersecurity company based in Reading, UK, specializing in computer and network security; 224 employees (+7.9% YoY growth), $6.0M revenue, founded 2013; provides penetration testing and security consulting, trusted by critical infrastructure organizations and highly regulated sectors.

Cybersecurity Consultancy
Managed Security Services
Data Privacy
+1 more
CYFOR Secure | Cyber Security

CYFOR Secure | Cyber Security

Comprehensive Network and Appl...
Manchester, United Kingdom 51 employees

Cybersecurity company based in Manchester, UK, with $4.1M annual revenue; specializes in penetration testing, digital forensics, incident response, vulnerability assessments, dark web monitoring, and cybersecurity audits; founded in 2002.

Penetration Testing
Vulnerability Scanning
Digital Forensics And Incident Response
+5 more
CyberCX

CyberCX

Comprehensive Penetration Test...
United Kingdom 1400 employees

UK-based cybersecurity company providing penetration testing, incident response, vulnerability assessments, and governance, risk, and compliance services; explicitly signals UK origin and offers detailed pentest solutions.

Penetration Testing
Incident Response
Vulnerability Assessments
+5 more
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tmc3

tmc3

Web Application Penetration Te...
United Kingdom 28 employees

IT services and cybersecurity company based in the United Kingdom; 20 employees with 27.3% YoY growth; founded in 2021; specializes in penetration testing, data protection, security assurance, and secure development lifecycle for government, critical infrastructure, and healthcare sectors.

Penetration Testing
Cybersecurity Consulting
Data Protection
+2 more
Cyberfort

Cyberfort

Application, Web, and Network ...
United Kingdom 156 employees

UK-based cybersecurity firm specializing in penetration testing services such as code reviews, cloud security testing, AI/LLM testing, and application/web/network/internals testing; performs active attack simulations to identify vulnerabilities.

Comprehensive Cybersecurity Services Including Consultancy
Penetration Testing
Cyber Resilience Audits
+3 more
Acutest

Acutest

Application Penetration Testin...
United Kingdom 30 employees

UK-based software testing and quality assurance consultancy; offers penetration testing services; registered in York, England, with additional UK addresses; specializes in testing software, business processes, and IT to improve digital transformation projects.

Software Testing
Quality Assurance
Penetration Testing
+5 more
BT Group

BT Group

Ethical Hacking and Penetratio...
London, United Kingdom 72813 employees

UK-based telecommunications company with 30,295 employees and GBP20.4B annual revenue; operates the largest fixed and mobile networks in the UK; provides active cybersecurity services including penetration testing and ethical hacking; GBP137.8M market cap; over $8.7B in funding; headquartered in London, UK.

Penetration Testing
Vulnerability Assessment
Ethical Hacking
+1 more
BreachLock

BreachLock

Penetration Testing as a Servi...
United Kingdom 121 employees

Cybersecurity firm based in London, UK, providing penetration testing, attack surface discovery, and red teaming services; offers continuous security testing and evidence-backed attack surface management.

Penetration Testing
Attack Surface Discovery And Management
Red Teaming
+2 more
Prolifics Testing

Prolifics Testing

Network and Application Pentes...
United Kingdom 500 employees

UK-based cybersecurity company specializing in penetration testing; employs CREST-certified professionals; offers internal and external testing for networks, web, mobile, and APIs; registered in the UK with company number 03814910; principal office in Borehamwood, Hertfordshire.

Penetration Testing
Security Testing
Software Testing Consultancy
+4 more
KiwiQA

KiwiQA

Application Penetration Testin...
United Kingdom 97 employees

UK-based software testing company specializing in penetration testing; explicitly offers pentest services to reduce security risks, with a UK address at Vista Business Centre, Hounslow, TW4 6JQ. Provides comprehensive QA and testing solutions.

Penetration Testing
Automation Testing
Manual Testing
+5 more
PwC

PwC

Ethical Hacking and Red Teamin...
United Kingdom 292491 employees

UK-based professional services firm with 120,836 employees and $55.4B revenue; offers assurance, tax, advisory, and cybersecurity services including penetration testing and ethical hacking (CREST-accredited); registered office at 1 Embankment Place, London; operates globally with a network of over 370,000 staff in 149 countries.

Audit And Assurance
Tax
Consulting
+3 more
Predatech

Predatech

Advanced Penetration Testing
Manchester, United Kingdom 9 employees

UK-based IT services and cybersecurity consultancy specializing in penetration testing, vulnerability management, and security certifications; 8 employees with 28.6% YoY growth since 2020; offers CREST-accredited pentest services and helps organizations enhance cyber defenses.

Penetration Testing
Managed Vulnerability Scanning
Cloud And Server Security Reviews
+2 more
Netcentrix

Netcentrix

IT Security Penetration Testin...
United Kingdom 50 employees

UK-based IT managed services provider specializing in cloud, infrastructure, security, and professional services; offers penetration testing services as indicated in their terms and conditions; registered in England with company number 03076196, headquartered in Buckshaw Village, Chorley, Lancashire.

Cloud Computing
Infrastructure Services
Security Solutions Including Penetration Testing
+4 more
3B Data Security

3B Data Security

CREST Certified Penetration Te...
United Kingdom 23 employees

UK cybersecurity company specializing in incident response, compliance, forensic investigations, and penetration testing; headquartered in Tunbridge Wells with operational address in Sawston, Cambridge; offers penetration testing services and extensive security consulting.

Cyber Incident Response
Compliance Consulting
Forensic Investigations
+3 more
Tranchulas

Tranchulas

Comprehensive Penetration Test...
London, United Kingdom 12 employees

Cybersecurity company specializing in penetration testing, red teaming, and threat intelligence; 11 employees with 20% YoY growth; founded in 2006; headquartered in London, UK; offers offensive and defensive cyber solutions, ISO 27001, incident response, and cyber training.

Penetration Testing
Red Teaming
Threat Intelligence
+5 more
Periculo

Periculo

Medical Device Penetration Tes...
United Kingdom 13 employees

UK-based IT services and cybersecurity consultancy with 11 employees, founded in 2015; specializes in cybersecurity for digital health including Penetration Testing, Cyber Essentials, ISO 27001, and Medical Device Security; 18.2% monthly growth, 1,720 monthly visits, ranked #8,134,692 globally.

Penetration Testing
Risk Assessments
Incident Response
+5 more
Evolve North Ltd

Evolve North Ltd

IT Environment Penetration Tes...
United Kingdom 11 employees

UK-based consultancy specializing in Governance, Risk, and Compliance, and IT Security and Assurance; provides penetration testing services to identify and remediate vulnerabilities in IT environments; headquartered in Durham, England, with registered office in North Yorkshire.

Governance
Risk And Compliance Consulting
IT Security And Assurance
+3 more
CyberOne

CyberOne

Comprehensive Network, Applica...
Other 95 employees

CyberOne (Comtact Ltd.) is a UK-based private cybersecurity firm specializing in proactive security testing, including CREST-accredited penetration testing; 51 employees with +23.4% YoY growth; $12M annual revenue; founded in 2005; offers integrated security solutions such as identity management, email, internet, and network security; recognized as one of 100 global Microsoft partners.

Managed Detection & Response
Penetration Testing
Cyber Incident Response
+4 more
SMARTSEC Information Security

SMARTSEC Information Security

Tailored Penetration Testing w...
Wakefield, United Kingdom 3 employees

UK-based cybersecurity consultancy founded in 2019 with 3 employees; specializes in penetration testing, Web3 & AI security, security operations, and vCISO advisory; offers comprehensive security solutions and compliance services.

Penetration Testing
Vciso Advisory
Advanced Security Testing
+5 more
SureCloud

SureCloud

Pentest-as-a-Service (PTaaS)
United Kingdom 48 employees

UK-based GRC and risk management software provider; offers penetration testing services including PTaaS with CREST accreditation; headquartered at 1 Sherwood Street, London W1F 7BL, England.

Governance
Risk
Compliance (grc) Software Solutions
+5 more
EJN Labs

EJN Labs

Web Application and API Pentes...
United Kingdom 11 employees

UK-based private cybersecurity firm specializing in AI-powered cyber defense, including penetration testing, red teaming, and bug bounty; CREST certified; 3 employees; Founded 2022; Headquarters in United Kingdom.

Penetration Testing
Red Teaming
Bug Bounty Services
+5 more
TIEVA

TIEVA

Comprehensive Penetration Test...
Leeds, United Kingdom 173 employees

UK-based IT services and consulting company specializing in transformative business IT solutions, multi-cloud strategies, and cybersecurity, including penetration testing services; 135 employees (+0.6% YoY growth); founded 2007; headquartered in Leeds, UK.

IT Services Including Cybersecurity
Penetration Testing
Cloud Solutions
+3 more
FluidOne

FluidOne

Proactive Penetration Testing
Other 251 employees

UK-based IT services and consulting firm specializing in secure data, voice, and cloud solutions; offers penetration testing and cybersecurity services; 152 employees, $132.4M revenue, founded 2006, headquartered in London, UK; recognized for high NPS and recent UK expansion.

IT And Cloud Managed Services
Cyber Security (including Penetration Testing And Vulnerability Assessments)
Data And AI Services
+2 more
URM

URM

Network and Application Penetr...
Reading, United Kingdom 135 employees

URM (URM Consulting Services Ltd) is a UK-based business consulting firm specializing in information security and risk management; 42 employees with 36.4% YoY growth, $1M-$5M revenue, founded in 2005, headquartered in Reading, UK. The company provides penetration testing, vulnerability assessment, ISO 27001, GDPR, PCI DSS, and business continuity services, with a global rank of #1,589,893 and 14,482 monthly visits.

Cyber And Information Security Consultancy
Penetration Testing
GDPR And PCI DSS Compliance
+4 more
Laburity

Laburity

Vulnerability Assessment and P...
United Kingdom 11 employees

Cybersecurity services provider based in the United Kingdom; specializes in vulnerability assessments, penetration testing, compliance, and code analysis; 9 employees; Founded 2022; Offers active penetration testing services and holistic cybersecurity solutions.

Penetration Testing
Vulnerability Assessment
Compliance Consulting
+5 more
SRM - Security Risk Management Ltd

SRM - Security Risk Management Ltd

Bespoke Penetration Testing
United Kingdom 39 employees

UK-based private information services company founded in 2002; specializes in cybersecurity with explicit penetration testing services to identify vulnerabilities; 4 employees, $6.5M revenue, $16.7K seed funding, part of Arcanum Group, with recent activity in security collaborations and innovations.

Penetration Testing
Vulnerability Testing
Cyber Incident Response
+5 more
CyberWhite Ltd

CyberWhite Ltd

Network, Cloud, and Applicatio...
United Kingdom 9 employees

CyberWhite Ltd is a UK-based cybersecurity consultancy specializing in penetration testing, risk mitigation, and security assurance; with 8 employees, founded in 2018, and a client-focused approach that emphasizes tailored security solutions, training, and compliance in cybersecurity standards.

Penetration Testing
Risk Mitigation
Information Security Advisory
+2 more
Barefoot Cyber

Barefoot Cyber

Penetration Testing Services
United Kingdom 9 employees

Cybersecurity company headquartered in the United Kingdom; specializes in penetration testing services with proven ability to scope, review, and execute pentest engagements.

Penetration Testing
Vulnerability Assessment
Managed Security Operations
+2 more
RightCue

RightCue

Network Penetration Testing
Basingstoke, United Kingdom 19 employees

Cybersecurity consulting firm specializing in compliance and penetration testing; 14 employees (+26.7% YoY growth); CREST-certified pentest services; Founded 2009; Basingstoke, UK.

Penetration Testing
Cyber Security Compliance Consulting
Risk Assessments
+4 more
Nellcote Ltd

Nellcote Ltd

Multi-Vector Penetration Testi...
United Kingdom 8 employees

UK-based private cybersecurity firm specializing in penetration testing and security consultancy; 5 employees with 33.3% YoY growth, founded in 2017, CREST accredited with expertise in active attack simulations across multiple environments, emphasizing personalized IT and cybersecurity services.

Penetration Testing
Cybersecurity Consultancy
Ransomware Readiness
+3 more
Cybergen Security

Cybergen Security

CREST-Accredited Penetration T...
United Kingdom 1 employees

UK-based cybersecurity company specializing in CREST-accredited penetration testing services; headquartered in Witney, Oxfordshire, with a focus on security testing and incident response.

Penetration Testing
Incident Response
Threat Intelligence
+5 more
cydentity.co.uk

cydentity.co.uk

Full-Spectrum Red Team Testing
United Kingdom 2 employees

UK-based cybersecurity firm specializing in proactive, business-driven protection; offers penetration testing and attack simulation services, including ransomware attack simulations; 2 employees; Founded 2025; Wales, UK.

Cybersecurity Consulting
Risk Assessments
Compliance Readiness
+4 more
Samurai Digital Security Limited

Samurai Digital Security Limited

Web Application Pentesting
Birmingham, United Kingdom 12 employees

Cybersecurity provider specializing in penetration testing, network intrusion, incident response, and information governance; UK-based with 4 employees, $1M-$5M revenue, founded 2016; NCSC certified, serving government and institutions, with CREST accreditation for penetration testing services.

Penetration Testing
Incident Response
Network Intrusion Detection
+5 more
Koris365

Koris365

Customized Automated and Manua...
United Kingdom 60 employees

UK-based IT and security managed service provider; offers penetration testing with customized automated and manual assessments, and cyber security evaluations; registered in England (Company No. 07709017), headquartered in Hemel Hempstead.

Penetration Testing
Cyber Security Evaluations
IT Managed Services
+5 more
DefensityOne

DefensityOne

Comprehensive Penetration Test...
Milton Keynes, United Kingdom 13 employees

DefensityOne is a cybersecurity solutions provider based in Milton Keynes, UK, specializing in proactive threat detection, risk management, and digital defense services. The company has 7 employees, was founded in 2015, and focuses on penetration testing, data security, and managed services, with an 18.8% YoY employee decline.

Cybersecurity Consulting
Managed Security Services
Penetration Testing
+2 more
Digital Insights Consultancy

Digital Insights Consultancy

Infrastructure and Cloud Penet...
Milton Keynes, United Kingdom 5 employees

Cybersecurity company based in Milton Keynes, UK; specializes in penetration testing, incident response, digital forensics, and SOC services; 3 employees with -44.4% YoY growth; founded 2019; offers tailored cybersecurity solutions including infrastructure and cloud pentest services.

Cybersecurity Services Including Penetration Testing
Digital Forensics
Incident Response
+5 more
Acumen Cyber

Acumen Cyber

Comprehensive Penetration Test...
glasgow, United Kingdom 31 employees

Acumen Cyber is a UK-based private cybersecurity firm with 23 employees and +40.9% YoY growth, providing 24/7 security services including MXDR, SaaS, cloud, email, web, DNS security, vCISO, and penetration testing; recognized for security testing capabilities and CREST accreditation.

24/7 Security Operations Centre
Managed Detection And Response (mxdr)
Vciso And Advisory Services
+5 more
Omnicyber Security

Omnicyber Security

Web Application Pentesting
United Kingdom 23 employees

Cybersecurity firm based in the UK and Canada; specializes in penetration testing, managed security, and compliance services; explicitly states penetration testing as a core service and UK presence.

Penetration Testing
Managed Security
Compliance Services
+2 more
GRC International Group

GRC International Group

CREST-Accredited Penetration T...
Ely, United Kingdom 32 employees

Cybersecurity company specializing in computer and network security; provides penetration testing services as part of its cyber-defense solutions; 25 employees; GBP 14.7M annual revenue; GBP 8.4M market cap; based in Ely, UK; operates in cybersecurity, IT services, consulting; global rank #8,652,681; 1,467 monthly website visits.

Penetration Testing
Cyber-defence-in-depth Strategies
Compliance Consulting
+4 more
Vorago Security

Vorago Security

Internal and External Network ...
United Kingdom 5 employees

UK-based cybersecurity company specializing in penetration testing; headquartered in Doncaster, England, with a registered office at 1 Water Vole Way, DN4 5JP; active provider of security testing services, including penetration testing, as detailed on their website.

Penetration Testing
Vulnerability Assessment
Risk Management
+2 more
Purecyber Limited

Purecyber Limited

Red Teaming Penetration Testin...
United Kingdom 43 employees

UK cybersecurity firm based in Cardiff; provides penetration testing, red teaming, and threat detection services; CREST-certified penetration testing capability; trusted by organizations worldwide.

Penetration Testing
Red Teaming
Threat Detection
+2 more
Akita

Akita

CREST-Accredited Penetration T...
United Kingdom 49 employees

UK-based IT company specializing in managed IT services and cybersecurity; offers CREST-accredited penetration testing services with headquarters in Sevenoaks, Kent, and Wrotham, Kent.

Managed IT Services
Cybersecurity
Crest-accredited Penetration Testing
+5 more
EY

EY

Penetration Testing and Red Te...
London, United Kingdom 391002 employees

Global professional services firm based in London, UK, with 279,628 employees and $51.2B revenue; offers advisory, assurance, tax, financial, and cybersecurity services including penetration testing and red teaming; competes with Deloitte and Accenture; active in public sector initiatives and social media.

Assurance
Consulting
Strategy
+5 more