Britons are being battered by millions of nuisance cold calls a year.

Two in five phone users have received a suspicious call in the last three months, according to data from communications regulator Ofcom.

Scammers frequently call out of the blue claiming to be from trusted businesses in the hope of gleaning personal information they can use to steal your money. 

They are able disguise their overseas numbers as UK numbers using a tactic known as spoofing. 

If you pick up and speak to them, they can clone your voice using artificial intelligence - allowing them to impersonate you and get past firms' security checks to confirm your identity.

We look at what the biggest phone networks are doing to quell the high number of scam and spam calls plaguing Britons on their phones each day.

O2 and Virgin Media

Virgin Media and O2 use a service called Call Defence which uses AI to flag suspected nuisance and scam calls. 

The service analyses phone numbers and determines whether it could be ​a scam or spam call. Customers are alerted to any risk before picking up by a display showing 'suspected spam' to help them decide whether ​they want ​​to answer the call or not.  

O2 was the first mobile provider to roll this out as a free service to its customers, with the technology flagging over 150million suspected scam and spam calls since launching last year.

Landline customers can also prevent nuisance or scam calls. They can register their number with the Telephone Preference Service (TPS) which will prevent unwanted calls or sign up for Virgin's Anonymous Caller Rejection which blocks incoming calls from withheld numbers.

BT and EE

EE provides a free of charge call screening service for its landline customers which has helped to block around 6million scam calls and flagged more than 57million as potential nuisance calls in the last year.

There is a paid-for service called Scam Guard which customers add on to their phone plan at a cost of £1 per month. 

It was created in partnership with software firm Norton and offers nuisance and scam call labelling, dark web monitoring, and access to three months of free Cyber Security Duo, covering identity and device protection.

BT is also deploying AI in the fight against nuisance calls, using a tool powered by US-based protection company Hiya which monitors incoming calls to notify customers of any suspected spam or scam calls. 

It introduced the scam prevention tool in May 2024 and in a four month period it  stopped 2.7million scam calls and 17.7million 'nuisance' spam calls.

Vodafone and Three

The merger of Vodafone and Three completed in June 2025 when it became the biggest mobile network in the UK, serving around 29million customers. 

Vodafone Three does not currently offer a specific display feature to filter suspected scam calls and display them as scam or spam calls on customers' phones. 

The phone network giant is looking into this area as the technology evolves.

Vodafone and Three say they collectively block 1.7million fraudulent calls to its customers each day. 

What can you do if you are plagued by scam calls

The Financial Conduct Authority advises that customers treat all unexpected calls, emails and text messages with caution. Don't assume they are genuine, even if the person knows some basic information about you.

Scam calls should be reported to the telecommunications watchdog, Ofcom, by forwarding them to 7726. 

Marijus Briedis, chief technology officer at VPN service provider NordVPN says: 'If you are seeing a spike in spoof calls, speak to your provider and see what they can do. 

'For example, EE offers Scam Guard that uses AI to filter out and label suspicious communications for a fee. 

'They should be offering these services as standard, but it might still be worth paying for the service if you receive scam calls on a regular basis.'