Find a pentest company with CHECK
40 companies have this certification
CHECK Certification
The CHECK (CHecklist Evaluating Computers and Key security) scheme was established by CESG (the UK government's National Technical Authority for Information Assurance, now part of the National Cyber Security Centre) in 1997. It was created to provide a structured framework for conducting information technology security assessments and penetration testing within UK government and critical national infrastructure environments. The scheme was designed to ensure that individuals performing security testing on sensitive systems possessed verified skills and adhered to established standards and methodologies.
The CHECK certification is highly valued because it represents government-endorsed validation of a security professional's ability to conduct rigorous, methodical security assessments. Organizations handling sensitive government data or operating within critical national infrastructure sectors often require CHECK-certified testers to ensure compliance with UK security standards. The certification's importance stems from its strict vetting process, which includes security clearance requirements and demonstration of technical competency, making CHECK holders trusted to access and test sensitive systems where standard commercial certifications may not suffice.
PwC
PwC (PricewaterhouseCoopers LLP) is a professional services firm with 120,836 employees and $55.4B annual revenue, based in Charlotte, NC; offers assurance, tax, advisory, and cybersecurity penetration testing services, including Red Teaming, Web, Infrastructure, Mobile, OT/ICS, and IoT Hacking, recognized as a CHECK-approved provider.
PwC
PwC is a private professional services firm with 120,836 employees and $55.4B annual revenue; based in Czechia with a Prague office at City Green Court, Hvězdova 1734/2c, Praha 4, confirming its formal Czech registration. The firm offers audit, assurance, tax, legal, deals, consulting, and cybersecurity services, including penetration testing validated by regional pages and CHECK certification, establishing its expertise in security testing.
Orange
Orange is a telecommunications and digital services provider headquartered in Issy-les-Moulineaux, France, with 38,184 employees and $43.6 billion in annual revenue. It has a EUR27.2 billion market cap and $6.5 billion in total funding, with recent acquisitions like MasOrange, S.L. Orange actively offers penetration testing services via its cybersecurity subsidiary, including Penetration Testing, Red Team Services, and Threat-Led Penetration Testing, emphasizing its capabilities in active security defense testing. The company is committed to social responsibility, digital equality, and building a safer digital world.
Vertical Structure (Acquired by Instil)
Cybersecurity company specializing in security and penetration testing; founded in 2006, based in Belfast, Ireland, with 3 employees. Offers human-based penetration testing, security consulting, and training, including CREST & CHECK, ISO27001, and Cyber Essentials. Focuses on a human-centric approach to cybersecurity with a small team and niche market presence.
IMRIM
Cybersecurity firm based in Luxembourg; specializes in information security advisory and penetration testing services across web, app, network, and infrastructure; headquartered at 17, rue Edmond Reuter, Bâtiment Bouvreuil, L-5326 Contern, Luxembourg; actively recruits penetration testers.
MDSec
MDSec is a UK-based private cybersecurity consultancy specializing in adversary simulation, application security, penetration testing, incident response, research, training, and technical security; with 38 employees (+1.7% YoY growth), $1M annual revenue, founded in 2011, and recognized for expertise in application, mobile, and hardware security, and targeted red team attacks.
Pentest People
UK-based security consultancy specializing in Penetration Testing as a Service (PTaaS); 76 employees with 20.2% YoY growth; offers web application and network penetration testing, simulating attacks to identify vulnerabilities; active in cybersecurity market with recent focus on security testing and cyber risk analysis.
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Rootshell Security
Rootshell Security is a UK-based private IT & Services company specializing in vulnerability management and penetration testing; 35 employees with 1.9% YoY growth, founded in 2019, headquartered in Basingstoke, UK. It is a leading provider of Penetration Testing as a Service (PTaaS), combining innovative technology with seasoned professionals to deliver vendor-agnostic security solutions and continuous threat exposure management.
Cyndicate Labs
UK-based cybersecurity consultancy specializing in penetration testing and red teaming; 6 employees with 28.6% YoY growth, founded in 2020, headquartered in Birmingham, UK. Offers web application testing, cyber scheme assessments, and cybersecurity consulting; 8,000 monthly website visits, ranked #2,039,956 globally.
Pen Test Partners
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.
Salus Cyber
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.
Ruptura InfoSecurity
UK-based IT services and cybersecurity company specializing in CREST & CHECK Approved Penetration Testing; 8 employees, 7.7% YoY growth, founded 2020, operates in a competitive global market with a modest web presence and active social media engagement.
RandomStorm Ltd
UK-based network security company providing enterprise security management tools and penetration testing services; employs 4 people, founded 2007, with $2.5M annual revenue; headquartered in United Kingdom.
Cyberis
Cyberis is a UK-based cybersecurity consultancy headquartered in Tewkesbury, Gloucestershire; specializes in information security with a focus on penetration testing, incident response, and simulated targeted attacks. The firm is CREST-accredited, demonstrating recognized expertise and compliance in penetration testing services.
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Surecloud Cyber Services
Cybersecurity company based in Gloucester, UK; specializes in penetration testing, including infrastructure and cloud security testing, with active vulnerability assessment and attack simulation capabilities.
Amr Cybersecurity
UK-based cybersecurity company providing penetration testing services with CREST accreditation; employs vetted, certified security experts for tailored testing, reporting, and post-engagement support.
CODA Security Limited
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.
Cyberlab
CyberLab is a UK-based cybersecurity firm specializing in penetration testing services; it explicitly offers penetration testing as a core service and is headquartered at Bridgford House, Heyes Lane, Alderley Edge, SK9 7JP.
Genius Security
UK-based IT services and cybersecurity consulting firm specializing in penetration testing (Black/White Box), web application testing, network vulnerability assessments, and cyber forensics; founded in 2018 with 2 employees, headquartered in Beaconsfield, Buckinghamshire.
Talion Cyber Security
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.
DigitalXRAID
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.
Jumpsec
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.
Resillion
UK-based IT services and consulting company specializing in quality engineering, cyber security, and media content; offers penetration testing services confirmed by NCSC CHECK certification, with 300 employees (+13.8% YoY growth), $25.4M annual revenue, and offices across North America, Europe, and Asia.
Prism Infosec
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.
Dionach
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.
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Aristi Limited
Cybersecurity company based in Birmingham, UK, specializing in CREST-certified penetration testing services; headquartered in Birmingham, West Midlands, UK.
SEC-TEC LIMITED
UK-based cybersecurity firm founded in 1999; specializes in penetration testing, PSN Health Checks, and InfoSec services; headquartered in Erith, Kent, with active operations serving organizations worldwide.
Six Degrees
IT Services and Consulting company based in London, UK, with 196 employees and $157.8M annual revenue; specializes in infrastructure, hybrid cloud, Azure management, and FinOps; explicitly offers penetration testing services including Penetration Testing as a Service and Red Teaming with CHECK/CREST accreditation; founded in 2011, with $145.9M in funding and active market presence.
MTI
Private UK-based IT & cybersecurity company with 214 employees, $45.6M revenue, founded in 1987; specializes in data security, data centre modernization, and IT managed services; provides penetration testing with CREST certification and active testing operations; acquired by Ricoh in 2020.
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Wavenet
UK-based IT managed services provider specializing in cybersecurity, communications, and connectivity; offers CHECK & CREST approved penetration testing services; headquartered in Solihull, England, with multiple UK offices; focuses on enhancing security and connectivity for businesses.
Modux
UK-based cybersecurity firm specializing in penetration testing and security assessments; NCSC-approved CHECK company with government accreditation; offers security testing for IT systems, products, and services, with proven expertise in assessing security weaknesses.
ProCheckUp
ProCheckUp Ltd is a UK-based cybersecurity firm specializing in penetration testing and security audits; CREST-approved and NCSC CHECK accredited, with headquarters in Portsmouth, England, and registered at 14 St Georges Business Centre, Portsmouth, PO1 3EZ.
CCL Solutions Group
Cybersecurity and digital forensics company based in the United Kingdom; specializes in penetration testing and breach simulation services, with a focus on identifying security vulnerabilities and protecting digital assets.
Trustmarque
UK-based IT services and consulting firm founded in 1987; employs 312 staff with $106.5M annual revenue; specializes in IT solutions, cloud, managed, and professional services for healthcare and government sectors. Offers CREST-certified penetration testing services with CHECK accreditation, emphasizing cybersecurity expertise; operates in a competitive landscape including Roke and ECSC Group.
Aon
Aon is a private financial services company based in London, UK, with 39,740 employees and $17.0B annual revenue; it offers consulting, risk management, insurance, actuarial, brokerage, and cybersecurity testing services, including CREST-certified penetration testing and red team assessments, demonstrating its comprehensive cyber resilience capabilities.
Citation Cyber
Citation Cyber is a UK-based IT services and cybersecurity consulting company with 23 employees and GBP 1.0M annual revenue; founded in 2012 and headquartered in Lancaster, UK. The firm specializes in certified penetration testing, including web, cloud, mobile, and physical assessments, to safeguard systems and data. It competes with Novicom, QSEAP, and Assured, and actively engages in cybersecurity news and awareness campaigns.
The Times
The Times is a private newspaper publishing company based in London, UK, with 703 employees (+18.1% YoY growth), $40M annual revenue, founded in 1785. It attracts ~25M monthly website visits and ranks #2,383 globally. The company provides UK, US, and world news, analysis, and headlines, with active penetration testing services as evidenced by multiple cybersecurity roles.
Cybergen Security
UK-based cybersecurity company specializing in CREST-accredited penetration testing services; headquartered in Witney, Oxfordshire, with a focus on security testing and incident response.
GRC International Group
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.
Content+Cloud
IT services and consulting company based in London, UK, with 72 employees and $110M revenue; specializes in Microsoft 365, Azure, Dynamics 365, and cloud infrastructure; rebranded as Advania UK; provides penetration testing services as a CHECK-certified provider.