Ofcom has announced a new ban that aims to protect people from the malicious use of mobile networks via Global Titles.

The UK regulator is banning the leasing of Global Titles – special types of phone numbers – by closing a technical loophole that is posing a risk to mobile user’s privacy and security.

Criminals can use Global Titles to intercept and divert calls and messages, and get their hands on information held by mobile networks. This could, for example, enable them to intercept security codes sent by banks to a customer via SMS messages. In extreme cases, these titles can be exploited by criminals and threat actors to even track the physical location of individuals anywhere in the world.

Global Titles are used by mobile networks to send and receive signalling messages, helping to direct a call or message to the intended recipient. These are used in the background of billions of calls and texts worldwide and are never seen by the individuals sending these messages.

These Global Titles are sometimes leased by mobile networks, largely to legitimate businesses who use them to offer mobile services.

If these titles fall into the wrong hands, however, this can lead to the security and privacy of ordinary mobile users being compromised, as their personal data may be directly or indirectly accessed by criminals.

Further, because those who intend to cause harm lease rather than own these numbers, they can hide their identities and work in the shadow of legitimate communications networks, Ofcom warns.

The Crackdown

While the risk posed by the leasing of Global Titles has been recognised by organisations like the UK’s National Cyber Security Centre (NCSC), and acknowledged by the telecoms sector, Ofcom says the current approach to the issue has proven ineffective.

In response, Ofcom’s ban on the leasing of Global Titles will take place with immediate effect.

“We are taking world-leading action to tackle the threat posed by criminals gaining access to mobile networks,” Ofcom group director for networks and communications, Natalie Black, said.

“Leased Global Titles are one of the most significant and persistent sources of malicious signalling. Our ban will help prevent them falling into the wrong hands – protecting mobile users and our critical telecoms infrastructure in the process.”

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NCSC Chief Technical Officer, Ollie Whitehouse said: “Today’s announcement marks an important step in the support of our mission to make the UK the safest place to live and work online.

“This technique, which is actively used by unregulated commercial companies, poses privacy and security risks to everyday users, and we urge our international partners to follow suit in addressing it.

“As the UK’s National Technical Authority for cyber security, we also congratulate Ofcom on their continued global leadership in this critical area.”

For any leasing that has already taken place, the ban will come into force on 22 April 2026 – a year’s time from the initial ban – aiming to give legitimate businesses time to make alternative arrangements.

Ofcom has also published new guidance for mobile operators on their responsibilities to prevent the misuse of Global Titles.