Two essential security assessments. One is a deep, manual investigation by a CREST-certified expert. The other is an automated scan for known weaknesses. Understanding the difference is critical to protecting your organisation.
Both play a vital role in a mature security programme — but they serve fundamentally different purposes.
How penetration testing and vulnerability scanning differ across key dimensions.
Manual and automated testing by a CREST-certified expert
Automated scanning using specialised tools
Deep — actively exploits vulnerabilities to demonstrate real risk
Surface — identifies known vulnerabilities from databases
3–10 days depending on scope
Hours to complete a full scan
Annually or after significant changes
Monthly or quarterly
From £2,500
From £300/month
Detailed report with proof of exploitation and remediation steps
List of detected vulnerabilities ranked by severity
Yes — tests complex logic flaws and multi-step attacks
No — cannot test business logic
Minimal — findings are manually verified
Can produce false positives requiring manual triage
Required for PCI DSS, ISO 27001, Cyber Essentials Plus
Supplements compliance programmes
Annual deep assessment and proving security posture
Continuous monitoring between annual assessments
The right choice depends on your goals, compliance requirements, and where you are in your security maturity journey.
The most effective security programmes combine both approaches for comprehensive coverage.
A comprehensive, expert-led deep dive into your defences. Identifies complex attack paths, business logic flaws, and provides verified proof of risk.
Continuous automated monitoring that catches newly disclosed vulnerabilities between your annual assessments. Keeps your security posture current.
Our Cyber 365 service combines continuous vulnerability scanning, EDR protection, and automated patching into a single managed solution — giving your organisation year-round security coverage without the complexity.
Common questions about penetration testing and vulnerability scanning.
Penetration testing is a manual, in-depth security assessment conducted by CREST-certified ethical hackers. Testers actively attempt to exploit vulnerabilities in your systems, applications, and networks to determine how an attacker could gain unauthorised access. The result is a detailed report with proof of exploitation and prioritised remediation guidance.
Vulnerability scanning is an automated process that uses specialised tools to identify known security weaknesses across your infrastructure, applications, and network devices. Scanners compare your systems against databases of known vulnerabilities and produce a report listing detected issues ranked by severity.
The main difference is depth and methodology. Penetration testing involves a skilled human tester manually attempting to exploit vulnerabilities, testing business logic flaws, and chaining weaknesses together to demonstrate real-world attack impact. Vulnerability scanning is an automated process that identifies known vulnerabilities but does not attempt exploitation.
Best practice is to conduct penetration testing at least annually and after any significant changes to your infrastructure or applications. Vulnerability scanning should be performed monthly or quarterly to provide continuous monitoring between penetration tests. Many compliance frameworks specify minimum frequencies for each.
Yes, many compliance frameworks require penetration testing. PCI DSS mandates annual penetration testing for organisations handling card payments. ISO 27001 requires regular security testing as part of its risk management controls. Cyber Essentials Plus includes a hands-on technical verification element. UK GDPR also expects organisations to regularly test and evaluate security measures.
No. While vulnerability scanning is valuable for continuous monitoring, it cannot replace penetration testing. Automated scanners cannot test business logic flaws, chain vulnerabilities together, or assess the real-world impact of a breach. Penetration testing provides the human intelligence needed to identify complex attack vectors that automated tools miss.
A professional penetration test report includes an executive summary for senior leadership, detailed technical findings with proof of exploitation, risk ratings for each vulnerability, step-by-step remediation guidance, and a retest to verify fixes have been applied correctly.
Penetration testing in the UK typically starts from around two thousand five hundred pounds for a focused web application test, with more comprehensive assessments costing more depending on scope. Managed vulnerability scanning services start from approximately three hundred pounds per month for continuous monitoring.
For robust security, yes. The two services are complementary. Penetration testing provides a deep, point-in-time assessment that uncovers complex vulnerabilities and business logic flaws. Vulnerability scanning provides continuous monitoring between annual pen tests, catching newly disclosed vulnerabilities quickly. Together, they form a comprehensive security testing programme.
Penetration testing can identify vulnerabilities that automated scanners miss, including business logic flaws, authentication weaknesses through session manipulation, privilege escalation chains, data exposure through complex multi-step attacks, insecure direct object references, and race conditions. These require human reasoning and creativity to discover.
Whether you need a one-off penetration test or ongoing managed security, our CREST-certified team is here to help.