What is Penetration Testing? — UK Software Development Guide

4 min readJune 2025ClickMasters Technical TeamReviewed by James Whitmore, CTO
what is penetration testing

Direct Answer

Penetration testing (pen testing) is a simulated cyber attack against a software system, network, or application to discover exploitable security vulnerabilities before malicious actors do. Penetration tests are conducted by security professionals ("ethical hackers") who use the same techniques as attackers but with authorisation from the system owner.

Penetration-testing in the UK

Penetration testing has specific UK regulatory significance. Cyber Essentials Plus certification requires an annual CREST-certified penetration test. DTAC Domain 3 (Technical Security) for NHS-connected apps requires CREST-certified pen testing. FCA-regulated firms should conduct penetration testing as part of their operational resilience programme (PS21/3). The NCSC recommends annual penetration testing for organisations processing sensitive data. CREST (Council of Registered Ethical Security Testers) is the UK body that certifies penetration testing organisations — CREST certification is the standard for UK regulatory compliance purposes.

Get Expert Advice on Penetration-testing

Get Expert Advice on Penetration Testing ClickMasters engineers apply Penetration Testing in every project. Free consultation. → clickmasterssoftwaredevelopmentcompany.co.uk/contact/