Card Payment Security: How to Protect Customers

• Compliance with the Payment Card Industry Data Security Standard (PCI DSS) is essential for protecting sensitive data and reducing fraud risks.
• Never store sensitive authentication data (SAD) and ensure all payment information is securely handled.
• Restrict access to payment data, enforce strong passwords, and use multi-factor authentication (MFA).
• Train employees to spot fraudulent behaviour in both in-person and online transactions.

Criminals use a range of tactics to exploit payment systems, so businesses must take a comprehensive approach to security.

The following sections outline essential measures to safeguard transactions, from securing customer data to training employees to detect fraud.

To start, any business that handles card payments must comply with the Payment Card Industry Data Security Standard (PCI DSS).

PCI DSS is a set of rules designed to protect cardholder data and prevent fraud. It applies to all businesses that process, store, or transmit card payment information.

Broadly, PCI DSS compliance requires:

• Secure cardholder data – Encrypt payment information and never store sensitive data like the card verification value (CVV).
• Control access – Use strong authentication measures to limit who can view or handle payment data.
• Monitor and test systems – Regularly check for vulnerabilities and ensure security measures are up to date.
• Maintain a security policy – Train employees on card payment security and enforce best practices.

Complying with PCI DSS fully should protect your business and customers from fraud. But effective card payment security involves multiple layers of protection. Below, we’ve explained how to meet PCI DSS requirements in more detail.

Protecting payment card data is critical for preventing fraud and maintaining customer trust. Unsecured sensitive information can fall into criminals’ hands.

To protect payment card data effectively, you should:

• Never store sensitive authentication data (SAD) – Data used to authenticate cardholders (such as PINs and full magnetic stripe data) should never be recorded or stored, even temporarily.
• Avoid writing down or recording card details – Staff should never jot down card numbers, expiration dates, or CVVs on paper or in unsecured digital formats.
• Delete payment data when no longer needed – Payment details should only be retained for as long as necessary to complete the transaction and meet legal or business requirements.
• Secure networks and payment systems – Use firewalls, encryption, and regular security updates to protect data from cyber threats.

Password protection is fundamental to card payment security.

• Enforce strong password policies – Require complex passwords that include a mix of uppercase and lowercase letters, numbers, and special characters. Passwords should be at least 12 characters long to reduce the risk of brute-force attacks.
• Ensure unique passwords for each user – Every employee should have their own login credentials rather than sharing accounts so you can track access.
• Require different passwords for different systems – Employees shouldn’t reuse passwords across different platforms, otherwise, one compromised password could give attackers access to multiple systems.
• Promote good password hygiene – Encourage staff to update passwords regularly, avoid writing them down, and use password managers to store credentials securely.
• Implement multi-factor authentication (MFA) – Add an extra layer of security by requiring a second form of verification, such as a one-time code sent to a mobile device.

Limiting who can access payment data is essential to prevent fraud and data breaches.

Employees, even trusted ones, should only ever have access to the bare minimum payment information they need to do their jobs.

To manage access securely, you should:

• Use strong authentication – Implement multi-factor authentication to verify user identities before granting access to payment systems.
• Restrict access by role – Follow the principle of least privilege and grant access to data only when it’s strictly necessary for a role or task.
• Monitor and log activity – Keep detailed access logs to track who interacts with payment data and detect any suspicious behaviour.

Fraudsters exploit weaknesses in payment processes, so businesses must be vigilant when handling transactions. Best practices differ depending on whether the payment is made in person or remotely.

For card present (i.e., in-person) payments, fraud risks include stolen cards, staff colluding with criminals and skimming devices attached to card readers that steal details during legitimate transactions.

To reduce these risks:

• Use EMV chip readers – Chip-enabled transactions prevent cloning, making them more secure than magnetic stripe payments.
• Inspect card readers regularly – Train staff to check for skimming devices or signs of tampering, especially on unattended terminals.
• Verify cardholder identity – Train staff to check IDs for high-value transactions and watch for unusual customer behaviour.
• Limit staff override permissions – Restrict manual overrides and refunds to prevent internal fraud.

Online and remote card-not-present payments carry a higher risk of fraud because neither the card nor the cardholder can be physically verified.

To secure these transactions:

• Implement Strong Customer Authentication (SCA) – SCA requires at least two of the following three authentication factors:
  • Knowledge – something only the customer knows
  • Devices – Something only the customer owns, like a smartphone or card reader
  • Inherence – Something inherent to the customer, such as a face scan or fingerprint
• Verify the card verification value – Require the three-digit CVV code to ensure the customer has the physical card.
• Monitor for unusual activity – Flag transactions with mismatched billing and shipping addresses or multiple rapid purchases.

Unusual customer behaviour can sometimes indicate fraud. Fraudsters can be noticeably nervous or overly assertive with staff, trying to pressure them into skipping card payment security measures.

You should be particularly wary if you sell high-value items or services. The thought of a big commission or hitting a sales target can be extremely enticing for employees. Criminals can exploit this feeling to rush through suspicious transactions.

For in-person payments, certain behaviours may signal potential fraud:

• Rushed or distracted behaviour – A customer appearing anxious, impatient, or eager to avoid security checks could be using a stolen card.
• Multiple card attempts – Trying several cards in quick succession may indicate fraud, especially if some are declined.
• Unusual purchasing patterns – A first-time customer making a high-value purchase with little concern for price or product details could be attempting fraud.
• Refusal to provide ID – Hesitation or resistance when asked for identification on high-risk transactions is a clear red flag.

Online and remote payments pose different fraud risks, often detectable through purchasing behaviour and transaction data:

• Mismatched information – Different billing and shipping addresses, especially in high-value orders, may indicate fraud.
• Unusual purchase frequency – Multiple purchases from the same customer in a short time, particularly using different cards, could suggest stolen card details.
• Large, fast first-time orders – Fraudsters may make high-value purchases without the usual customer hesitations or considerations, hoping to exploit stolen payment details before detection.
• High-risk geolocation – Orders from regions associated with fraudulent transactions should be reviewed carefully.

Despite advances in technology, people are still integral to card payment security. You need to understand how to implement safeguards, apply best practices, and notice unusual behaviours, which is where training comes in.

Our online PCI DSS Training course provides the knowledge needed to handle card transactions securely. This CPD-certified course covers key PCI DSS compliance requirements, responsibilities, and practical strategies for protecting customer payment details. Users will learn how to process transactions securely, recognise fraud risks, and apply best practices for both in-person and remote payments.

Help your team prevent fraud and ensure PCI DSS compliance. Enrol in our PCI DSS Training today.