Penetration testing firm trusted by nine of the top ten US banks, with the Resolve platform for continuous attack surface management.
Accreditations: SOC 2, ISO 27001, CREST
Services: Web Application, Network, Cloud, API +7
Best CREST Penetration Testing Companies (2026)
CREST accreditation is the gold standard for penetration testing quality assurance. CREST-accredited companies undergo rigorous assessment of their testing methodologies, staff qualifications, and data handling practices. Choosing a CREST-accredited provider gives you confidence that your penetration test will be conducted to the highest professional standards.
About this list
The list opens with our Featured partner, SECFORCE, a CREST-accredited offensive security consultancy specialising in adversary simulation and CBEST-approved threat-led testing, clearly labelled as a paid placement. Below them, the wider directory is ordered by our scoring methodology, which evaluates accreditation depth, team expertise, review quality, and service breadth.
Related: CHECK pen testing companies · CBEST-accredited companies · Pen testing companies in the UK
Featured partnerFeatured
SECFORCE
UK offensive security consultancy delivering CREST-accredited penetration testing, adversary simulation and CBEST, TIBER-EU and TBEST threat-led testing, mainly for financial services and other large organisations.
CRESTCBESTSTARISO 27001ISO 9001
- Holds CREST, CBEST, STAR, ISO 27001, ISO 9001, and Cyber Essentials accreditations.
- In business since 2008 (Companies House 06488355); CREST-accredited for penetration testing since 2011.
- CBEST-accredited since 2015; first TIBER engagement in 2018.
- CREST accreditations: penetration testing, vulnerability assessment and threat-led penetration testing (formerly STAR).
46 providers
CREST-accredited UK penetration testing consultancy based in Shropshire, delivering web application, API, infrastructure, cloud, mobile, and AI/LLM testing. A small specialist team, with a retest included in every engagement.
Accreditations: CREST, CREST AI Penetration Testing, Cyber Essentials, IASME Cyber Assurance, Cyber Essentials Plus
Services: Web Application, API, Network, Cloud +4
Global enterprise cybersecurity consultancy founded in 1999 in Oxford, holding rare CREST STAR-FS accreditation and delivering penetration testing, red and purple teaming, and PCI QSA services across five international offices.
Accreditations: CREST, CHECK, STAR, ISO 27001, PCI QSA +1
Services: Web Application, Network, Red Teaming, Purple Teaming +7
Global Big Four professional services firm delivering CREST, CHECK, and CBEST-accredited penetration testing and red teaming services from London, serving the UK's largest enterprises and regulated organisations.
Accreditations: CREST, CHECK, CBEST, STAR, ISO 27001 +1
Services: Web Application, Network, IoT, Cloud +9
CREST and CHECK-accredited UK penetration testing and managed security provider formed in 2026 from Pentest People, Bulletproof, and Target Defense, with CREST STAR/TLPT-FS capability and the GuardNest vulnerability management platform.
Accreditations: CREST, CHECK, STAR, NCSC Assured, ISO 27001 +1
Services: Web Application, Network, Mobile App, API +8
Elite UK offensive security consultancy specialising in CBEST/STAR/TIBER red teaming, advanced adversary simulation, and CREST-accredited penetration testing for FTSE 100 clients.
Accreditations: CREST, CHECK, CBEST, STAR, ISO 27001 +2
Services: Web Application, Network, Cloud, Red Teaming +6
Full-service London-based cybersecurity consultancy with CREST, CHECK, and NCSC accreditations delivering offensive testing, managed detection, and strategic advisory services.
Accreditations: CREST, CREST AI Penetration Testing, CHECK, ISO 27001, Cyber Essentials +2
Services: Web Application, Network, Cloud, API +5
Global managed security provider with the elite SpiderLabs penetration testing team and deep PCI DSS compliance expertise.
Accreditations: PCI QSA, ISO 27001, SOC 2, CREST
Services: Web Application, Network, Mobile App, Cloud +6
Manchester-based independent cybersecurity consultancy with over 20 years of experience delivering CREST and CHECK-accredited penetration testing, red teaming, and compliance certification services.
Accreditations: CREST, CHECK, ISO 27001, Cyber Essentials, Cyber Essentials Plus +1
Services: Web Application, Network, Mobile App, Cloud +5
CREST and CHECK-accredited UK penetration testing consultancy with CBEST approval, specialising in infrastructure, application, and simulated attack assessments across the public and private sectors.
Accreditations: CREST, CHECK, CBEST, STAR, ISO 27001 +3
Services: Web Application, Network, Mobile App, Cloud +4
CHECK and CREST-accredited Birmingham-based cyber security consultancy with over 15 years of experience delivering penetration testing, red teaming, and OT security assessments for government and private sector clients.
Accreditations: CREST, CHECK, ISO 27001, Cyber Essentials, Cyber Essentials Plus +1
Services: Web Application, Network, Mobile App, Cloud +7
Fast-growing CREST and CHECK-accredited UK cybersecurity consultancy with deep expertise in critical national infrastructure sectors.
Accreditations: CREST, CHECK, ISO 27001, Cyber Essentials Plus
Services: Web Application, Network, Cloud, API +6
Best CREST Penetration Testing Companies (2026), FAQs
What is CREST accreditation for penetration testing?+
CREST (Council of Registered Ethical Security Testers) is an international accreditation body that certifies the competence and professionalism of cybersecurity service providers. CREST-accredited pen testing companies have demonstrated rigorous standards for methodology, staff qualifications, data handling, and reporting quality.
Why should I choose a CREST-accredited pen testing company?+
CREST accreditation provides assurance that the company follows industry-recognised standards, employs qualified testers, uses proven methodologies, and handles your data securely. Many compliance frameworks and regulators specifically recommend or require CREST-accredited testing.
Is CREST accreditation recognised globally?+
Yes. CREST is recognised internationally and has member companies across the UK, Europe, Asia-Pacific, and the Americas. CREST is particularly well-established in the UK, Australia, and Singapore, and is increasingly recognised in other regions.
What is the difference between CREST and CHECK?+
CREST accredits commercial penetration testing services. CHECK is a UK government scheme operated by the NCSC specifically for testing government systems. Many UK pen testing firms hold both accreditations.
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