UK telecom regulator Ofcom has unveiled new rules and guidance aimed at strengthening protections against mobile messaging scams and spoofed international calls, requiring mobile operators to take tougher action against fraudsters exploiting mobile networks.
The move comes as fraud continues to be one of the UK’s biggest criminal threats. Fraud accounts for an estimated 45 percent of all reported crime incidents in England and Wales, while criminals stole £1.28 billion from victims during 2025. Ofcom also revealed that 40 percent of UK mobile users received at least one suspicious text message within the past three months, highlighting the growing scale of mobile-based fraud.
Mobile Operators Required to Strengthen Scam Defences
Ofcom’s new regulatory framework requires mobile providers to adopt stronger measures to identify, block and disrupt both person-to-person messaging scams and business messaging fraud.
For person-to-person scams, mobile operators must collect intelligence on scam messages, malicious web links and fraudulent phone numbers from customers and anti-fraud organizations. Providers will then be required to block scam numbers, stop fraudulent messages while they are being transmitted across their networks, and detect malicious web links and phone numbers embedded in text messages.
The regulator is introducing volume limits for pay-as-you-go SIM cards, making it significantly harder for criminal gangs to send mass scam messages using large numbers of prepaid SIM cards.
Stricter Controls for Business Messaging Platforms
Business messaging providers and message aggregators will face enhanced compliance requirements designed to prevent fraudsters from abusing enterprise messaging services.
The new rules require providers to perform rigorous Know Your Customer (KYC) and ongoing Know Your Traffic (KYT) checks before allowing organizations to send bulk mobile messages. Operators must continuously monitor messaging activity, investigate suspected fraud, and remove abusive customers.
Ofcom is targeting abuse of Alphanumeric Sender IDs, the business names that appear instead of phone numbers in legitimate text messages. Providers must verify that sender names genuinely belong to the businesses using them and prevent criminals from impersonating trusted brands such as delivery companies, banks or government agencies.
Where fraudulent activity is detected, operators must implement incident management procedures, block malicious sender IDs, web links and phone numbers, and take action against organizations that fail to conduct adequate verification.
600 Million Scam Messages Already Blocked Annually
According to Ofcom, mobile operators are already blocking more than 600 million scam messages every year through existing industry initiatives. However, the regulator believes stronger and more consistent protections are necessary as scammers continue to evolve their techniques.
The latest rules are designed to complement the UK Government’s ban on SIM farms and commitments made by mobile operators under the Fraud Sector Charter, creating a more coordinated national approach to combating telecom fraud.
New Guidance Targets International Spoof Calls
Alongside messaging protections, Ofcom has introduced tougher guidance to combat international scam calls that spoof UK mobile numbers.
Under the new guidance, telecom companies should withhold caller ID information for international calls claiming to originate from UK mobile numbers unless the number’s authenticity can be verified. Criminal groups frequently use spoofed UK numbers to increase the likelihood that consumers will answer fraudulent calls.
While callers may occasionally see withheld numbers from legitimate organizations, Ofcom advises consumers to remain cautious when answering withheld or unfamiliar numbers.
Consumers Encouraged to Report Scam Messages
Ofcom continues to encourage consumers to report suspicious text messages and scam calls by forwarding them to 7726, enabling mobile providers to improve fraud detection systems and strengthen network-level protections.
Amy Jordan, Ofcom’s Strategy Delivery Director, said the enhanced measures are intended to disrupt criminal activity at its source and help the telecom industry stay ahead of increasingly sophisticated fraud techniques.
Chief Superintendent Amanda Wolf, Head of Report Fraud Operations, welcomed the new protections, saying stronger requirements for mobile providers would help reduce fraudulent messages and spoofed calls targeting UK consumers.