Avoiding Common Mistakes Under PCI DSS 4.0

With the release of PCI DSS 4.0, compliance expectations are more stringent than ever. One misstep can lead not only to fines but also to reputational damage, loss of customer trust, and revenue disruption. Organizations that were once confident in their compliance status are now encountering pitfalls introduced by the updated framework. Whether you're maintaining your current posture or seeking to achieve compliance for the first time, understanding and avoiding common missteps is essential.

Below are four critical areas where we continue to see avoidable errors—each with heightened significance for PCI DSS 4.0 compliance.

1. Clearly Defining and Documenting Your PCI DSS 4.0 Scope

Scoping issues are one of the most frequent and impactful mistakes organizations make. This has only become more prevalent with PCI DSS 4.0, which requires a formal sign-off on your scope and its completeness.

Scope should include all systems that store, process, transmit, or could impact the security of cardholder data. This means identifying and documenting hardware, software, databases, cloud environments, and third-party service providers involved with your Cardholder Data Environment (CDE).

To stay compliant:

• Review your CDE regularly
• Document all in-scope systems and components
• Ensure scope sign-off is completed and communicated early in the assessment process

Bringing this documentation to your QSA at the beginning of the engagement will help reduce friction during the audit.

2. Timing and Approval of ASV Scans under PCI DSS 4.0

A common compliance pitfall is misunderstanding the timing and requirements for ASV scans. While the PCI Council requires scanning “at least once every 90 to 92 days,” many organizations overlook this window, especially when it falls on weekends or holidays.

To mitigate risk:

• Perform scans monthly rather than quarterly
• Use a PCI SSC-approved scanning vendor
• Confirm that scans are submitted for approval
• Ensure all in-scope assets are included in the scans

Monthly scanning adds minimal cost and builds consistent visibility into vulnerabilities. More importantly, it ensures you meet the Council’s strict timing guidelines.

3. Conducting Access Reviews on the Right Schedule

While annual access reviews were once the norm, PCI DSS 4.0 now mandates reviews at least every six months. The specific timing, “every 180 to 184 days,” means that simply scheduling two reviews a year may not be enough.

Best practices include:

• Setting calendar reminders for compliance deadlines
• Documenting the results of each access review
• Using automated tools where possible to support the process

Timely reviews help identify and revoke unnecessary access, reducing both risk and non-compliance.

4. Detecting Failures in Critical Security Controls under PCI DSS 4.0

Another area where organizations can fall short is in identifying failures of key security systems. These include firewalls, IDS/IPS, malware protection, audit logs, and physical access controls.

PCI DSS 4.0 requires that failures be:

• Detected in a timely manner
• Trigger alerts
• Prompt a documented response

To meet these expectations, implement continuous monitoring for all critical controls. Establish clear escalation procedures and response plans to resolve failures as they occur. These measures not only help with compliance but also support a stronger overall security posture.

Final Thoughts on PCI DSS 4.0 Compliance and Readiness

Maintaining PCI compliance under version 4.0 requires more diligence, documentation, and precise timing than ever before. By proactively addressing these common issues—scope definition, ASV scan timing, access review frequency, and system failure detection—organizations can significantly reduce their risk and ensure a smoother assessment experience.

If you need support navigating the complexities of PCI DSS 4.0 or want to assess your current environment, contact Adam Lisowski with Freed Maxick Risk Advisory Services at adam.lisowski@freedmaxick.com or 716.362.6203. Let’s work together to safeguard your compliance and protect your business.