Best Practices for Securing Payment Terminals

Payment terminals have evolved far beyond simple card readers. Today, they’re intelligent, connected devices that process sensitive payment data, communicate across enterprise networks, and receive ongoing software updates throughout their lifecycle.

As payment technology advances, so do attackers’ tactics. Protecting payment devices today requires more than checking a compliance box. It requires a layered approach that addresses the device itself, the network it operates on, and the software that keeps it running securely.

While every deployment is different, organizations that consistently apply security best practices across multiple layers are better positioned to reduce risk, maintain compliance, and protect customer trust.  

Use the checklist below to evaluate and strengthen the security of your payment terminal estate.  

Payment device security has three layers:

• Physical security: Protect the device from theft, tampering, and substitution.

• Network security: Protect payment traffic through segmentation, encryption, and monitoring.

• Software and updates: Keep terminals protected with trusted software and timely security patches.

Payment terminal security checklist

Physical security 

A payment terminal that can be removed, opened, or replaced can be compromised without ever touching the network. Physical security is the first layer of defense and helps prevent unauthorized access before it becomes a cybersecurity issue.

Best practices

• Deploy terminals in attended or monitored locations wherever possible and avoid unsupervised placement. 

• Secure terminals to counters or fixed fixtures to deter theft, removal, or device substitution. 

• Use anti-theft locks where appropriate to provide an additional layer of security.

• Secure power and communication cables to reduce opportunities for tampering or device substitution.

• Store spare and replacement payment devices in secured locations with a restricted, documented access process.

• Reconcile deployed terminal serial numbers against inventory records regularly to detect unexpected changes or missing devices. 

• Cover or disable unused physical ports, such as USB ports, except during authorized maintenance. 

• Train frontline staff to recognize signs of tampering and verify the identity of anyone servicing a payment terminal.

• Inspect deployed terminals routinely for signs of tampering or substitution as part of your PCI DSS device inspection procedures.

Compliance note: PCI DSS Requirements 9.5.1 require organizations to periodically inspect payment devices for signs of tampering or substitution and train personnel to recognize and report suspicious behavior.

Network security 

Once payment data leaves the terminal, it travels across networks that should be treated as untrusted. Strong network controls reduce the attack surface and help prevent unauthorized access to payment systems. 

Best practices

• Segment payment terminal traffic onto a dedicated VLAN, isolated from corporate and guest networks. 

• Protect cardholder data in transit using Point-to-Point Encryption (P2PE) whenever possible.

• Use firewall policies to restrict outbound communications to only approved payment processing endpoints only. 

• Monitor continuously for unexpected connections, unusual traffic patterns, or unrecognized network destinations. 

• Enforce strong authentication and password policies for terminals connected to wired or wireless networks.  

• Perform regular vulnerability assessments and penetration testing to identify emerging security risks and validate existing controls.

Software and update hygiene 

Security is not static. As vulnerabilities are identified, vendors release firmware and software updates that strengthen device protections, improve stability, and address newly discovered threats. Keeping payment terminals current is one of the most effective ways to reduce risk. 

Best practices

• Establish a regular schedule for deploying firmware and application updates across your payment estate.

• Maintain a centralized inventory of deployed software versions to quickly identify devices running unsupported or outdated software. 

• Verify that all updates are digitally signed and originate from trusted sources before deployment. 

• Validate updates on a small group of terminals before rolling them out across the broader estate. 

• Deploy critical security patches as soon as practical rather than waiting for the next scheduled maintenance window. 

Recommended update cadence

Verifone recommends reviewing and updating terminal software at least annually to benefit from the latest features, performance improvements, and security updates. Critical security patches should be applied as soon as they become available, regardless of where a device falls within its normal maintenance cycle. 

Security is an ongoing practice

A single control or annual compliance exercise can not achieve payment terminal security. It depends on disciplined operational practices across physical security, network protection, software maintenance, and employee awareness.

Organizations that regularly review these layers stay ahead of emerging threats while keeping the payment environment resilient.  

At Verifone, security is built into every layer of the payment ecosystem — from tamper-resistant hardware and secure software development to encryption, device management, tokenization, and ongoing software updates. Combined with disciplined operational practices, these capabilities help organizations strengthen their payment environment and accept payments with confidence.

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