The UK telecommunications regulator Ofcom has introduced new restrictions on number spoofing to address international scam calls that impersonate UK phone numbers. The measures expand upon previous efforts to block calls from abroad that imitate UK landline numbers by extending protections to UK mobile numbers, coming at a time when SIM swap fraud has increased by 1,055 percent in the UK telecommunications sector.
Under the new regulations, phone providers must block calls originating from outside the UK that falsely display UK landline numbers. The strengthened industry guidance has taken effect as of July 2025, building upon Ofcom’s earlier initiatives to combat telecommunications fraud, including the ban on Global Title leasing which addressed critical mobile network security vulnerabilities.
The regulator is now proposing that telecom companies should withhold the caller ID of calls appearing to come from a UK mobile number roaming abroad unless the number’s validity can be verified. The measure aims to prevent scammers from exploiting the current exemption for roaming calls while ensuring legitimate calls can still connect. Similar approaches have shown success in other regions, with India’s anti-spoofing system reducing fake international calls by 80 percent.
Ofcom has opened a consultation period running until October 13, 2025, with plans to publish its final decision in early 2026.
“Customers endure a barrage of scam calls, and when people get caught out, the consequences can be devastating,” said Marina Gibbs, Ofcom’s Policy Director for Networks and Communications. “It can happen to anyone, with criminal gangs in other countries trying to exploit people when their guard is down.”
Gibbs noted that existing measures have resulted in blocking approximately one million calls daily, adding: “There’s no silver bullet, and we’re always looking for new ways to shore up our defences in the fight against fraud. These new measures would provide further protection for people in the UK.”
The initiative is part of Ofcom’s broader strategy to combat fraud and scams across telecommunications and online services. The effort comes as the UK faces increasing challenges in mobile security, with mobile banking fraud rising by 62 percent in recent years, highlighting the urgent need for enhanced telecommunications security measures.
The new framework includes mandatory blocking of spoofed calls from abroad, verification requirements for UK mobile numbers used while roaming, and continued monitoring of effectiveness through consultation with industry stakeholders. The measures are similar to initiatives in other countries, such as Singapore’s local-only call filtering system, showing a global push toward stronger telecommunications security.
Sources: Ofcom, Ofcom Consultation, ISPreview, Telecoms Tech News
