How to protect your point-of-sale systems

Whether you run a retail or service business, your POS system sits at the heart of your customer experience. It also represents a key target for cyber criminals, with UK Finance reporting that over £600m was stolen through payment-related fraud in the first half of 2025 alone.

Understanding how POS systems work, why they’re targeted, and what practical steps you can take to protect them is essential for keeping customer data safe and maintaining trust in your business.

A POS system includes more than just the card terminal on your counter. It typically covers the payment device, any connected applications, the network it runs on, and supporting systems such as back-office software or customer management tools.

These systems are attractive to hackers because they handle sensitive cardholder data. If compromised, a single device can expose large volumes of customer information. Many POS systems are also briefly unattended during busy periods, creating opportunities for tampering. Meanwhile, outdated software or poorly configured networks can further increase risk, even if you are by the till.

There are several ways cyber criminals attempt to compromise POS systems: 

• Malware: This type of software can infiltrate outdated systems and capture card data during transactions. In some cases, it can spread across connected systems, widening the impact. 
• Physical and digital skimming: Criminals may attach fake overlays or devices to terminals to capture card details or inject malicious code into online payment environments to intercept data. 
• Weak network security: If your POS system shares the same network as guest Wi-Fi or staff devices, attackers may be able to access it through a less secure entry point. 
• Day-to-day oversight: Missed warning signs, such as unusual device behaviour or unverified maintenance visits, are often a factor in successful attacks. 

One: use industry-approved technology and enable system updates.

Protecting your POS environment starts with choosing the right technology. Use modern, supported payment devices from trusted suppliers rather than older or second-hand terminals that may no longer receive updates or meet current security standards. Look for devices that encrypt payment data automatically at the point of transaction and do not store card details locally. Keeping these devices and any connected software up to date will also help protect your business against known vulnerabilities and malware. 

Network separation is also critical. Best practice is to have your POS system on a dedicated network, isolated from general internet use.   

Two: Establish strict access controls and lock down devices.

Access control is key. Avoid shared logins, use strong passwords, and restrict permissions to only those who need them. Removing access promptly when staff leave is just as important, and its good practice to lock down devices by disabling unused ports and preventing unauthorised applications from running. Plus, any systems that require a login shouldn’t be left unattended without being locked beforehand.  

Spotting a compromised POS system early can significantly reduce impact. Physical warning signs may include damaged casings, broken seals, unfamiliar attachments or cables, or mismatched serial numbers. 

You should also be alert to changes in behaviour, such as slower performance, unexpected reboots, or unknown applications appearing on the system. Operational red flags, such as unannounced technician visits or reports of fraudulent transactions from customers, should always be taken seriously.

Building POS security into your routine can make a big difference. A simple way to do this is to include POS checks as part of your existing opening, closing, or health and safety routines.  

On a daily or weekly basis, check devices for signs of tampering and ensure they remain connected only to secure networks. 

Each month, apply updates, review user access, and check security software logs.  
 
Quarterly, review your overall set-up, including encryption and supplier arrangements, and test your response to potential incidents. On a yearly basis, assess your broader compliance and ensure your systems and processes are still fit for purpose. This can be achieved by engaging with an industry expert who can provide services around independent validation of either compliance or security set-up. It may be cheaper than waiting until you have an incident. 

POS security is not a one-off task. It’s an ongoing process that combines the right technology, clear processes, and informed staff. By taking a proactive approach, you can reduce the risk of fraud, protect your customers, and build confidence in your business. As cyber threats continue to evolve, staying vigilant and following best practice will help ensure your payment systems remain secure.

Don’t assume your payment devices are secure just because they’re in place and working. Take a few minutes to review your setup: 

• Check your contracts: Are you entitled to the latest devices? Are you actually using them?  
• Confirm software is current: Your POS systems should be supported and receiving regular security updates  
• Know your supplier process: Make sure your team understands how legitimate device swaps happen – fraudsters often pose as suppliers to replace terminals. 

Now look at your environment: 

• Are devices positioned where staff can always see them?  
• Could someone tamper with them without being noticed?  

Now, make sure your people feel confident spotting potential risks: 

• Do employees know what suspicious activity looks like?  
• Would they know how to respond to a potential compromise?  

Help your team spot the warning signs. Explore our Security Awarness Training and give them the skills to recognise fraud, phishing and device tampering. A quick review today can help prevent fraud tomorrow.