Best UK Penetration Testing Companies (2026)
The United Kingdom has one of the most mature penetration testing markets in the world, underpinned by CREST accreditation, the NCSC-run CHECK scheme for government systems, and CBEST threat-led testing for financial institutions regulated by the Bank of England. UK buyers benefit from a deep pool of accredited providers, but that also means more noise to cut through when shortlisting.
When choosing a UK provider, look for CREST accreditation as a baseline, CHECK approval if you are testing government or public-sector systems, and CBEST or TIBER-EU experience for regulated financial services. The providers below all operate in the UK market; the list opens with our Promoted partner, clearly labelled, followed by the wider editorial directory ordered by accreditation depth and verified capability.
Related: CREST pen testing companies · CHECK pen testing companies
SECFORCE
Canary Wharf-based adversary simulation and CBEST-aligned penetration testing consultancy, delivering CREST-accredited offensive security to UK financial services and other organisations with the most demanding requirements.
NCC Group
Global cybersecurity consultancy with CREST, CHECK, and CBEST accreditation, renowned for deep technical research and comprehensive penetration testing services.
Nettitude
CREST, CHECK, and CBEST accredited UK consultancy within Lloyd's Register, delivering premium penetration testing for government and critical infrastructure.
Pen Test Partners
The UK's largest independent security testing firm, renowned for IoT/OT research, CBEST red teaming, and CHECK/CREST-accredited penetration testing across all sectors.
Dionach
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.
PwC Cyber Security
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.
MDSec
Elite UK offensive security consultancy specialising in CBEST/STAR/TIBER red teaming, advanced adversary simulation, and CREST-accredited penetration testing for FTSE 100 clients.
Secarma
Manchester-based independent cybersecurity consultancy with over 20 years of experience delivering CREST and CHECK-accredited penetration testing, red teaming, and compliance certification services.
Cyberis
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.
Aristi
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.
Bridewell
Fast-growing CREST and CHECK-accredited UK cybersecurity consultancy with deep expertise in critical national infrastructure sectors.
Best UK Penetration Testing Companies (2026), FAQs
What accreditations should a UK penetration testing company have?+
CREST accreditation is the baseline standard for commercial UK penetration testing. For government and public-sector systems, look for CHECK approval, run by the NCSC. For intelligence-led red teaming of financial institutions, CBEST is the Bank of England's framework. ISO 27001 and Cyber Essentials Plus are common supporting certifications.
How much does penetration testing cost in the UK?+
A focused UK web application or external network pen test typically costs between £4,000 and £12,000. Larger infrastructure engagements and red teaming run higher, with CBEST and TIBER-EU programmes reaching £50,000 or more. Day rates for UK CREST-accredited consultants typically range from £900 to £1,500.
Do UK pen testing companies work with financial services regulation?+
Yes. The strongest UK providers have direct experience with FCA operational resilience expectations, CBEST intelligence-led testing for Bank of England-regulated firms, and DORA for firms with EU exposure. SECFORCE, our Promoted partner on this page, specialises in CBEST and TIBER-EU threat-led testing for UK financial services.
What is the difference between CREST and CHECK in the UK?+
CREST accredits commercial penetration testing services and is the most widely recognised standard for UK businesses. CHECK is a UK government scheme operated by the NCSC specifically for testing government and public-sector systems. Many UK firms hold both; CHECK companies must also maintain CREST accreditation.