How to maintain PCI DSS compliance long-term

Maintaining PCI DSS compliance, especially in smaller teams, can seem like a daunting task. The good news is that it’s entirely achievable as long as you have a structured plan and the right policies and procedures in place to manage risks and protect sensitive payment data.  

To help you, we’ve put together five key areas to focus on to comfortably maintain PCI DSS compliance over the long term. 

1. Defining your scope 

The first step in maintaining PCI DSS compliance is understanding your scope: what systems, networks, and processes are involved in handling cardholder data at your organisation? 

• Document your scope clearly. Scoping documents should cover all payment channels and system components where cardholder data is stored, processed, or transmitted, as well as any connected systems that could impact security.
• Keep it simple. Your documentation should be easy to follow, so both your team and an external assessor can easily understand it.
• Choose the correct SAQ. The appropriate Self-Assessment Questionnaire (SAQ) should be selected depending on your individual payment channel. Make sure your environment meets the eligibility criteria for that SAQ. It’s essential the correct SAQ is selected from the start, or you might face risk of non-compliance.
• Reduce scope where possible. You can minimise compliance effort by segmenting networks and keeping systems that don’t handle card data separate from the Cardholder Data Environment (CDE). 

2. Documenting policies and defining roles & responsibilities 

It's important to establish and maintain appropriate and clear documentation that supports your PCI DSS compliance. Requirements should be backed by appropriate policies and procedures detailing how its done.  You can check your specific Self-Assessment Questionnaire (SAQ) and its testing guidance to understand which requirements at a minimum must be supported by documented policies and procedures. 

• Define roles and responsibilities and ensure they’re understood by key personnel. This could include:
  • Who is responsible for implementing or reinforcing a policy?
  • Who is responsible for carrying out BAU activities?
• Ensure accountability: Documents without clear ownership could get ignored or might not be enforced consistently. 

3. Managing third parties 

Third parties, like your suppliers, can have a major impact on your PCI DSS compliance, especially if they handle, store, or process cardholder data on your behalf. These third parties should be PCI DSS compliant themselves or be able to evidence compliance when required. 

• Perform due diligence checks. Assess new vendors before onboarding to ensure they won’t impact your compliance. This process should be documented and repeatable.
• Audit suppliers annually. Review your suppliers regularly for compliance with the standards you require
• Have written agreements. Contracts should clearly outline PCI responsibilities and include a right-to-audit clause where you need them to provide evidence to support your compliance.
• Compliance evidence. PCI-compliant vendors should provide a valid Attestation of Compliance (AOC) on request. Non-PCI-certified vendors who perform PCI-related services must still provide evidence of meeting your compliance needs.
• Create a responsibility matrix. Define exactly which PCI requirements each vendor is responsible for and ensure this is documented. 

All third parties should be clearly documented, along with details around the services they provide and their impact to your scope. Consider a having a process in place for switching providers if necessary. 

4. Patching and vulnerability management  

Unpatched systems and unmanaged vulnerabilities are a common cause of security breaches and PCI DSS has requirements for managing them. 

• Implement a patch management process. Ensure you have a process to identify missing patches and vulnerabilities in a timely manner. Make sure you receive notification when a new patch is released from a vendor.
• Test before deployment. Patches should be tested appropriately before applying them, and be installed within one month of vendor release.
• Scan regularly. PCI DSS requires ‘critical’ vulnerabilities to be patched within one month of identification. ASV and internal vulnerability scans need to be passed every quarter. It's recommended to run scans monthly.  
• Understand shared responsibility. Using cloud or third-party systems doesn’t automatically transfer patching responsibility – you still need to own this process internally.
• Risk-rank vulnerabilities. Some findings from scans may be false positives or irrelevant to your scope, so not a true risk to your business – Findings should be risk ranked appropriately and managed in line with the risk they pose.  
• Penetration testing. Annual penetration testing must be carried out in line with the business methodology by a qualified tester. A penetration test can contextualise vulnerabilities and link vulnerabilities together, identifying their true risk. Vulnerabilities that are identified to be exploitable must be fixed in a timely manner as per PCI DSS requirements. 

5. Incident Response 

Incidents will inevitably happen, so it’s essential to be prepared to ensure you can recover with minimal disruption. 

• Create an Incident Response and Business Continuity plan. These plans should define clear roles and steps for handling incidents, how operations will continue to run, restoring systems, and recovering efficiently from disruption.
• Test your plans. Test your plans through exercising to be confident that they will hold up in a real crisis. Keep your plans up to date as systems and responsibilities evolve.
• Include playbooks. Document how to respond to known or expected scenarios and add new ones as new threats emerge.
• Include cloud-based systems in your plan. Understand your cloud provider’s uptime SLAs and recovery points- because you might find they don’t align with your business needs.
• Map systems and logs. Know which systems are in scope, and where you’ll get the data needed to investigate incidents. 

PCI DSS compliance isn’t just a one-time exercise- it’s an ongoing commitment that requires effective planning and documentation, with structured systems in place to minimise risks and keep payment data secure. Integrating these efforts with day-to-day operations, PCI DSS compliance will become much more manageable and sustainable over the long term. 

Get in touch with us today to find out how we can support you with PCI DSS.