Phone Networks to Block Scam Calls from Abroad

UK phone networks have agreed to automatically block calls from abroad that spoof UK numbers, in an effort to clamp down on a surge of phone-based scams.

Ofcom said it is working with telecoms companies to “implement technical solutions” to the recent explosion of fraud, including call blocking. 

Lindsay Fussell, networks and communications group director at the regulator, said the measures will be “introduced as a priority, and at pace, to ensure customers are better protected.”

Data released by Ofcom last week exposed the colossal scale of scam phone calls and texts, revealing that 44.6 million Britons—82% of adults—received suspicious communications on their phone just in three months over this summer. 

Landline users are particularly vulnerable to the scams peddled over phones, with 61% of people aged 75 and over reporting they received a potential scam call to their house phone this summer.

Many of these calls are made by foreign gangs using technology to make the call appear as if it originates in the UK. In even more sophisticated ruses, criminals “spoof” the numbers of British banks and swindle victims out of thousands of pounds.

Automatically blocking every call coming from abroad if it shows up with a UK Caller ID would prevent hundreds of millions of scam calls from connecting, Ofcom estimates.

At the regulator's request, the NICC, the UK telecoms standards body, representing major landline and mobile networks including BT, Sky, TalkTalk and Virgin Media, has drawn up guidance on the blocking of inbound international calls.

Under the proposals, the only international UK-numbered calls that would be allowed through would be those from roaming mobiles or legitimate call centres, such as those run overseas by British companies.

Some major phone networks are already blocking spoofed calls from abroad, using AI to identify them, and others are expected to follow within months.

“We have identified that a large proportion of scam calls are made from abroad in this way,” an unnamed source told the Telegraph.“This isn’t a silver bullet, but we believe that blocking this traffic will have a significant impact.”

However, technological limitations prevent the UK from adopting a plan as strict as that announced by the United States’ Federal Communications Commission (FCC), which announced this month that it will force phone companies to block millions of scam texts.

A government source said a similar scheme wouldn’t work here because much of the UK phone network still relies on copper-based ISDN technology. However, Ofcom is “encouraging” UK networks to accelerate the move to internet-based VOIP, on which scam texts can be more easily detected and blocked.

Ofcom is also considering whether customers should be required to show ID when purchasing multiple SIM cards, which are often used by fraudsters to blitz Britons with millions of scam text messages. However, the regulator is concerned that these rules may “marginalise” vulnerable groups who don’t have identification.

All stakeholders are also aware that scammers quickly evolve to overcome any firewall. “It’s rather like whack a mole because the scammers can adapt so quickly to everything we try to do,” the source told the Telegraph.