For organisations aligning with ISO 27001 or PCI DSS, understanding where penetration testing is mandatory versus expected best practice is critical for both compliance and effective risk management.

Penetration testing in ISO 27001

ISO 27001 does not explicitly require penetration testing. Instead, it adopts a risk-based methodology, meaning organisations must identify threats to their information assets and implement appropriate controls to mitigate them. This flexibility allows organisations to tailor their security approach based on their specific risk landscape.

However, penetration testing plays a significant role within this model and is highly recommended to utilise. Controls such as technical vulnerability management and security testing emphasise the need to identify weaknesses in systems and applications. Penetration testing is one of the most effective ways to achieve this, particularly for internet-facing systems, critical infrastructure, or environments handling sensitive data.

In practice, certification bodies often expect evidence of security testing where risk justifies it. If an organisation’s risk assessment identifies credible attack paths, penetration testing becomes a logical and defensible control. At that point, it is effectively required within the organisation’s own Information Security Management System (ISMS). Failing to implement it where risk dictates can result in audit findings or non-conformities.

Penetration testing in PCI DSS

Unlike ISO 27001, PCI DSS makes penetration testing a mandatory requirement. Under Requirement 11.4 of PCI DSS v4.0, organisations must conduct both internal and external penetration testing at least annually and after any significant change to systems or infrastructure.

This requirement is prescriptive and detailed. Testing must cover the full cardholder data environment (CDE), including systems that store, process, or can impact cardholder data. It must also include both internal and external perspectives to simulate realistic attack scenarios.

Segmentation testing is another key component. Where organisations rely on network segmentation to isolate the CDE, penetration testing must validate that these controls are effective. This is required at least annually, and more frequently for service providers, who may need to test every six months.

PCI DSS also emphasises quality and methodology. Organisations must use industry-recognised approaches, ensure testers are suitably qualified and independent, and produce detailed reports. Crucially, any identified exploitable vulnerabilities must be remediated and retested to confirm fixes, demonstrating that security controls are not only in place but effective.

In short, penetration testing is not optional under PCI DSS. It is a defined compliance obligation with clear scope, frequency, and validation requirements.

Aligning compliance with security outcomes

Although ISO 27001 and PCI DSS take different approaches, they share the same objective: reducing risk and protecting sensitive information. ISO 27001 provides flexibility, allowing organisations to determine when penetration testing is necessary, while PCI DSS mandates it as a baseline control.

In practice, many organisations adopt penetration testing as a standard activity regardless of compliance requirements. It delivers real-world insight into how attackers could exploit weaknesses, going beyond automated scanning to uncover complex attack paths and chained vulnerabilities.

How Integrity360 can support with penetration testing

Integrity360’s penetration testing services are designed to simulate real-world cyberattacks, providing a rigorous assessment of your organisation’s cybersecurity posture. Using a team of certified ethical hackers, engagements are conducted to identify exploitable weaknesses before threat actors can take advantage, giving organisations a proactive edge in managing risk.

Rather than focusing solely on isolated vulnerabilities, Integrity360 evaluates how weaknesses across systems, networks, and applications can be combined to create viable attack paths. This approach provides a more accurate representation of real-world risk and enables organisations to prioritise remediation based on business impact.

These services support organisations in strengthening overall resilience while also aligning with key regulatory and compliance frameworks, including ISO 27001 and PCI DSS. By identifying and validating exposures, organisations can demonstrate due diligence, support audit readiness, and ensure that security controls are operating effectively.

Beyond compliance, penetration testing plays a direct role in reducing the likelihood of costly incidents. Early identification of weaknesses helps prevent data breaches, operational disruption, and financial loss, while also reinforcing trust with customers, partners, and stakeholders.

Integrity360’s experts deliver detailed, structured reporting that supports both technical teams and senior decision-makers. Findings are clearly prioritised, with practical remediation guidance tailored to the organisation’s environment.

Whether preparing for an audit, introducing new systems, or strengthening existing defences, Integrity360 provides actionable insight and expert support to help organisations stay secure and compliant.

Are you in need of Penetration testing services? Contact us and our experts can help you.