Suspicious calls: do you know when to call 159?

Most of us are wary of answering calls and texts from numbers we don’t know. And with good reason.

Across the UK, Ofcom research found that 42% of phone users reported receiving a suspicious call in early 2025, while 51% of mobile users reported receiving a suspicious text message. For many, these came through thick and fast, with 32% of mobile users reporting suspicious messages at least weekly.

These figures may not even show the full extent of the issue. The true scale of the problem could be much higher than these figures show, as Ofcom's research shows that many people don't report suspicious calls and messages.¹ In this article, we take a look at how phone scammers work and why calling the number ‘159’ could just be your lifeline.

Because they know many people will ignore their calls or hang up as soon as they become suspicious, phone scammers focus on volume. They don’t need every call to succeed. Instead, they rely on a small number of people engaging. After all, it only takes one moment of distraction for even the savviest among us to reveal a compromising piece of information.

The rise of AI is also playing into their hands, helping scammers to automate processes that once had to be done manually. It can even be used to clone voices, allowing criminals to impersonate family members, celebrities and even trusted organisations, making scam attempts harder to spot and easier to deploy at scale.²

Phone scammers are often part of highly organised criminal operations. They work to scripts, have internal departments, follow processes and are target-driven. Many spend their time studying your bank’s internal procedures so they can convincingly mimic them and gain your trust. 

Their aim is to keep you on the phone as they build this trust. They know that many people will be suspicious, so they come armed with reassuring responses designed to lower your guard.

A scammer might say something like: "You're absolutely right to question me, and I'm more than happy for you to hang up and call the bank directly. However, we need to act quickly because your account is under attack right now."

This professional approach, combined with a sense of understanding, can catch you off guard. Once established, this false sense of security is underlaid with urgency. It's this combination of trust and pressure that can make even the most cautious of people act before they've had time to think.

Faced with that sense of urgency, you might start to wonder: If I hang up and call my bank directly, how long will it take?

With automated menus to navigate and potential hold times to contend with, it can be tempting to stay on the line with the caller. After all, if your account is really at risk, surely every second counts?

That's exactly what scammers are hoping you'll think.

When a caller pressures you to act immediately, remember these three numbers: 159.

Working in a similar way to 101 for the police or 111 for the NHS, 159 is the UK's hotline for reporting and checking suspected bank fraud.

The idea is, if someone calls claiming to be from your bank and you're not sure whether they're genuine, hang up and call 159.

You will be directed straight to your bank's fraud team, allowing you to verify whether the call was legitimate and if any further action needs to be taken. This number currently links in with many of the UK's major banks, including Barclays, Halifax, HSBC, NatWest and Monzo.³

Their message is simple: before giving away any information, even if the caller sounds legitimate, stop, hang up and call 159.

A genuine caller will have no issue with you calling this number. In fact, any trusted bank worker would welcome it. Someone with ill intent, on the other hand, may become defensive or increase the pressure. They’ll encourage you to stay on the line, arguing there's no time to hang up or that disconnecting could make the situation worse. Take these as warning signs.

This pressure is all the more reason to end the call and contact your bank directly.

While many scammers target individuals, they’re using the same techniques directly against businesses.

Businesses are increasingly experiencing their employees being contacted by scammers posing as banks, suppliers, IT providers and management. This approach can be particularly effective against new or less experienced employees under the pressure of being asked by someone more senior. If an employee does grant access or give away sensitive information, the consequences can be far-reaching. 

Cyber insurance is an important line of defence to help businesses respond if an attack succeeds, but before your business reaches that stage, creating a culture of ‘questioning before acting’ is equally as important.

That’s why it’s important to educate employees about social engineering tactics, giving them the confidence to step back and challenge unexpected requests.

The information contained in this article is for general information purposes only. It does not constitute legal or other professional advice and cannot be relied upon as such. Should you have any queries, we recommend that you consult the appropriate professional adviser. The links provided in this document are for reference only. Please note that we are not responsible for the content of any linked site.

Sources:

1. 08-NICC-Open-Forum-2025-Combating-Scam-calls-Ofcom.pdf

2. AI Scams 2025: Complete Guide to Every Threat

3. STOP, HANG UP, CALL 159 - Stop Scams UK