The Payment Card Industry Data Security Standard (PCI DSS) is designed to protect credit cardholder data and ensure businesses handling payment information maintain secure environments. Compliance is essential for preventing data breaches, avoiding regulatory fines, and maintaining customer trust. Organizations processing, storing, or transmitting cardholder data must adhere to PCI DSS, regardless of whether they outsource these activities to third parties. But knowing what to do to get and stay PCI DSS compliant can be confusing. Continue reading for an overview of the fundamentals of PCI DSS and how application security helps businesses get and maintain compliance.

Do Customers Care About Data Security?

Before we dive into the specifics, it’s important to address the elephant in the Zoom room. A question that comes up a lot with PCI DSS is whether it actually matters to customers whether a business is PCI DSS compliant. While customers may not actively think about PCI DSS on a regular basis, they do care about the security it represents. Research shows customers are very concerned about the security of their data and would pay more for products with a lower cybercrime risk. PCI DSS indicates a business takes their sensitive payment information seriously and is actively protecting it against potential breaches, which can make customers more likely to choose a PCI compliant business over one that isn’t. So, yes, PCI DSS compliance can feel forced upon businesses and at the end of the day, it truly does help businesses earn and maintain trust.

General PCI DSS Compliance Requirements

PCI DSS compliance is built on fundamental security principles that reduce the risk of data exposure. Key requirements include:

1. Build and maintain a secure network and systems
2. Protect cardholder data
3. Maintain a vulnerability management program
4. Implement strong access-control measures
5. Regularly monitor and test networks
6. Maintain an information security policy

These requirements establish a strong security foundation and help organizations proactively identify vulnerabilities before they become critical risks. While each PCI DSS version has a slightly different breakdown of what’s included in the above six categories, there are twelve requirements that have consistently been a part of PCI DSS since its inception. Those are:

1. Install and maintain network security controls.
2. Apply secure configurations to all system components.
3. Protect stored account data.
4. Protect cardholder data with strong cryptography during transmission over open, public networks.
5. Protect all systems and networks from malicious software.
6. Develop and maintain secure systems and software.
7. Restrict access to system components and cardholder data by business need to know.
8. Identify users and authenticate access to system components.
9. Restrict physical access to cardholder data.
10. Log and monitor all access to system components and cardholder data.
11. Test security of systems and networks regularly.
12. Support information security with organizational policies and programs.

Application Security Requirements of PCI DSS

Ensuring software application security is an integral part of PCI DSS compliance. Developers and security teams must:

1. Follow Secure Coding Guidelines – Use OWASP-recommended best practices to prevent vulnerabilities. The OWASP Developer Guide is a great resource for secure coding categories and practices.
2. Regularly Test Applications for Common Vulnerabilities – Conduct security testing for threats like SQL injection and cross-site scripting (XSS).
3. Enforce Version Control – Prevent unauthorized changes and maintain an audit trail of modifications.
4. Encrypt Sensitive Data – Securely store and transmit cardholder data using industry-standard encryption.
5. Implement Secure Authentication and Session Management – Ensure strong authentication methods and protect user sessions from hijacking attempts.

Incorporating these practices into the software development lifecycle (SDLC) minimizes risk exposure and strengthens compliance.

Who Needs to Comply with PCI DSS?

PCI DSS applies to any company that accepts, stores, transmits, or processes cardholder data. This includes:

1. Retailers and Merchants – Even if they use third-party processors, they are still responsible for compliance.
2. Service Providers – Companies that develop, host, or manage software handling payment data must meet PCI DSS requirements.
3. Software Developers – If your software affects how cardholder data is processed or stored, compliance is mandatory.

To achieve PCI compliance, you first need to determine which requirements apply to your business. Compliance is divided into four levels based on your annual credit card transaction volume. Depending on your level, you will need to implement different processes like regular vulnerability scanning. Merchant levels are:

• Level 1: Over six million transactions annually
• Level 2: Between one and six million transactions
• Level 3: Between 20,000 and one million transactions, and all e-commerce merchants
• Level 4: Less than 20,000 transactions

Service providers, like payment gateways and processors, have additional security obligations since they handle cardholder data for other businesses.

Risks of Non-Compliance with PCI DSS

PCI DSS is not just a regulatory requirement, it’s a crucial security framework that protects cardholder data and mitigates financial and reputational risks. Without compliance, businesses face threats such as:

1. Compromised Payment Systems – Card readers and databases are prime targets for attackers.
2. Unauthorized Network Access – Weak security controls make payment systems vulnerable.
3. Data Theft – Cardholder data can be stolen through unsecured storage, compromised physical records, or unauthorized system access.
4. Regulatory Fines and Penalties – Non-compliance can result in substantial financial penalties and loss of customer trust.

By correctly implementing PCI DSS, organizations establish a baseline for data security that safeguards payment information and reduces the risk of costly breaches. Compliance isn’t just about avoiding fines, it’s about proactively protecting your business and your customers.

To learn more about PCI DSS, download version 4.0.1 here or talk to our team about the application security requirements in PCI DSS.