By Jade Hancock June 2, 2025
In today’s digital commerce environment, security is more than a back-end concern—it is a core part of every business that handles card payments. The Payment Card Industry Data Security Standard (PCI DSS) was introduced to help businesses protect customer cardholder data. Compliance with this standard is mandatory for any business that stores, processes, or transmits card information. Despite its importance, many businesses stumble during their PCI compliance efforts, often due to avoidable errors.
Understanding PCI Compliance
PCI DSS is a set of security standards developed by the major credit card companies to secure sensitive cardholder data. It outlines specific requirements across twelve key areas, such as secure network management, access control, encryption, and monitoring.
Why PCI Compliance Matters
Failing to comply with PCI standards can result in fines, penalties, reputational damage, and increased liability in the event of a data breach. However, compliance is more than a legal obligation. It shows your customers that you prioritize their privacy and security, which builds trust and encourages loyalty.
Despite this, many businesses still struggle to fully comply. These failures often result not from malice or negligence, but from misunderstandings, outdated practices, or poor implementation.
Mistake 1: Storing Cardholder Data Unnecessarily
One of the most frequent and risky mistakes is storing sensitive cardholder data when it is not required. While some businesses believe retaining this information might be useful for recurring billing or refunds, the added risk is rarely worth it.
Why This Is a Problem
The more cardholder data you store, the more attractive your business becomes to cybercriminals. Additionally, storing sensitive data increases your responsibility to protect it, requiring more complex security measures and increased audit scrutiny.
The best approach is to use tokenization or work with payment processors that handle all storage externally. If you don’t need to store cardholder data, don’t.
Mistake 2: Misunderstanding Your PCI Scope
Another major misstep is failing to correctly define the systems and processes that fall under PCI scope. Many businesses assume that if they outsource payment processing, they are no longer responsible for compliance. This is only partially true.
The Importance of Defining Scope
Even if a third-party provider handles your card transactions, any system that transmits or touches that data is still within scope. This includes point-of-sale devices, web applications, and any server that interfaces with the payment processor. Failing to properly identify in-scope systems leads to gaps in protection and non-compliance.
Regularly conduct network segmentation reviews and update your scope as your infrastructure evolves.
Mistake 3: Infrequent Vulnerability Scanning
PCI DSS requires regular vulnerability scans to identify security weaknesses in systems that are connected to the internet. However, many businesses either skip these scans or only perform them once annually, which is not sufficient.
The Role of Vulnerability Scans
A quarterly scan by an Approved Scanning Vendor (ASV) is mandatory for many businesses. These scans check for known vulnerabilities in your network, including outdated software, exposed ports, and misconfigured firewalls.
Failing to conduct regular scans or ignoring the results can lead to missed threats and ultimately a failed PCI compliance report.
Mistake 4: Ignoring Failed PCI Scans
Conducting a scan is not enough. You must also take action if the scan fails. Unfortunately, many businesses ignore the scan results or delay remediation, putting both compliance and security at risk.
The Cost of Inaction
PCI DSS requires that any high or medium-level vulnerability identified during a scan must be addressed before compliance is achieved. Ignoring these findings not only invalidates your scan but also increases the risk of a breach.
If your scan fails, work with your ASV or IT team to resolve the issues promptly and schedule a rescan to confirm fixes.
Mistake 5: Using Outdated Security Protocols
Older versions of security protocols such as SSL and early TLS are no longer considered safe. Still, many businesses continue to use them out of convenience or due to legacy systems.
Upgrading to Strong Protocols
PCI DSS now requires that all encrypted transmissions use TLS 1.2 or higher. Using outdated protocols will result in failed scans and non-compliance. Upgrade your systems and make sure any third-party services you use meet current encryption standards.
Mistake 6: Incomplete or Incorrect Self-Assessment Questionnaires (SAQs)
The SAQ is a crucial part of PCI compliance for smaller businesses that do not undergo a full formal audit. However, many businesses rush through this process or misunderstand the questions, leading to inaccurate or incomplete submissions.
Understanding the Right SAQ Type
There are multiple SAQ types, each tailored to specific business models. Choosing the wrong type or misrepresenting your data environment can create compliance issues. It is important to carefully review the guidance documents and consult with your payment provider or a PCI expert if unsure.
Mistake 7: Weak Passwords and Access Controls
Weak passwords and poor user management continue to be a significant vulnerability. Many businesses fail to enforce strong password policies or use shared login credentials among staff.
Strong Authentication Practices
PCI DSS requires that each user have a unique ID and that access to systems storing or processing cardholder data is restricted based on business need. Enforce complex passwords, use multi-factor authentication, and regularly review access logs and user permissions.
Mistake 8: Poorly Configured Firewalls
Firewalls are essential to protecting your network perimeter, but they are only effective if configured correctly. Some businesses install a firewall and never revisit its settings, or worse, disable critical protections for convenience.
Regular Configuration Reviews
PCI DSS requires that firewalls are configured to block unauthorized traffic, restrict inbound and outbound connections, and protect cardholder data environments. Review firewall rules regularly and ensure they align with best practices.
Mistake 9: Lack of Employee Training
Even the most secure systems can be compromised by human error. Phishing, mishandling data, or using unauthorized devices are all common problems when employees are not adequately trained.
Security Awareness Programs
Employees must be educated about the importance of cardholder data security and their role in protecting it. Regular training sessions, phishing simulations, and clear data handling procedures are essential to reducing internal risks.
Mistake 10: Not Keeping Policies Up to Date
PCI DSS requires a formal security policy that outlines how cardholder data is protected and how security is managed across the business. Many businesses draft a policy once and never update it.
Ongoing Policy Management
Your policy should be a living document that evolves with your technology, business operations, and threat landscape. Review and update it at least annually, or whenever significant changes occur.
Mistake 11: Inadequate Logging and Monitoring
Failing to monitor system activity is a serious oversight. Without logging and monitoring, businesses may miss signs of a breach or be unable to determine what happened if one occurs.
Setting Up Effective Monitoring
Implement logging tools that track access to cardholder data, configuration changes, and failed login attempts. Logs should be reviewed regularly and retained for at least a year as required by PCI DSS.
Mistake 12: Assuming Compliance Equals Security
Some businesses treat PCI compliance as a checkbox task. Once completed, they believe their systems are safe. This mindset is dangerous.
Security as a Continuous Practice
While PCI compliance provides a strong baseline, it is not foolproof. New threats emerge constantly, and attackers find new ways to exploit even compliant systems. Use PCI compliance as the foundation of your security efforts, not the end goal.
How to Avoid These Mistakes
Avoiding these common mistakes starts with awareness and a commitment to proactive security management. Here are a few strategies to help maintain ongoing compliance.
Partner with the Right Providers
Use reputable payment processors and hosting providers who understand PCI requirements and offer built-in compliance tools. This can reduce the complexity of maintaining compliance on your own.
Perform Regular Risk Assessments
Risk assessments help identify potential vulnerabilities and prioritize mitigation efforts. Schedule them at least annually and whenever major infrastructure changes occur.
Establish a Compliance Calendar
Set up reminders for key PCI tasks such as quarterly scans, policy reviews, employee training, and SAQ completion. A structured approach reduces the risk of missing critical steps.
Document Everything
Keep records of your compliance efforts, scan results, training logs, and security updates. This documentation will be essential in the event of an audit or breach investigation.
Conclusion: Proactive Measures Prevent Compliance Failures
PCI compliance is not a one-time project or a mere checklist. It is an ongoing process that requires attention to detail, regular assessments, and a deep understanding of your business environment. The most common mistakes—from storing unnecessary data to ignoring failed scans—are often preventable.
Businesses that succeed in PCI compliance are those that treat it as a core part of their operational culture. They understand that protecting cardholder data builds trust, reduces risk, and supports long-term growth.
By learning from the missteps of others and building a sustainable compliance program, your business can meet PCI standards with confidence and protect both your operations and your customers.