Reused phone numbers are leaving people exposed to scams, hacking and nuisance calls

A new investigation by consumer watchdog Which? has found that mobile phone users are also being contacted by drug dealers and debt collectors as telecoms firms recycle numbers

Reused phone numbers are leaving Britons exposed to hacking, nuisance calls or being cut off.

An investigation by consumer watchdog Which? has uncovered various risks posed by existing phone numbers that get reused by other consumers – from social media and online accounts getting hacked to older people losing access to their emergency phone lifeline. Which? has also had reports of people being bombarded with calls and messages from debt collectors as well as trying to buy drugs from them.

The problem exists because many of the ‘new’ numbers given out by telecoms firms in the UK are recycled from previous owners, Which? said. There is a fixed pool of 11-digit combinations that begin with an 07 prefix, so telecoms providers must recycle mobile numbers to meet customer demand.

A third of people said they did not know that phone companies can reallocate landline and mobile phone numbers which are no longer in use. One in 10 people told Which? they had changed their mobile number within the past decade.

Of those that had done so, only half had updated their number with all relevant accounts and organisations. A quarter had only updated with some of their accounts, while 10% admitted they had not updated their number anywhere.

Which? is concerned that accounts and online identities are in danger from hackers if people do not update the phone number they have registered. Meanwhile, mobile numbers are recycled when previous users have their number deactivated for “non-use”. To people who use their phone every day, being deactivated for low use is a very unlikely prospect. The shortest timescale for losing a number, 70 days of non-use according to Ofcom, might look reasonable at first glance.

However, some people do not use their mobile phones in this way, and instead keep them for emergencies only. For example, people enduring domestic abuse may keep a ‘safe phone’ hidden away without their abuser’s knowledge and several people told Which? about older relatives who had been cut off without their consent due to infrequent use of their phone.

Several networks told Which? they either do not warn customers they are about to be disconnected or warn them by texting the very numbers that are not in regular use. Which? believes providers should also be using any other agreed contact methods, such as emails listed on the customer's account to alert them.

Which? are now calling on Ofcom to look into deactivation communications, alongside the issues that recycled numbers are causing consumers.

Lisa Barber, Which? Tech editor, said: “Our research shows that recycled phone numbers can cause significant problems for both the previous owner of the number and the new recipient – from the risk of being hacked to losing an emergency phone line or receiving worrying unsolicited messages. Ofcom should aim to improve the way providers communicate that a number is at risk of deactivation and look into the issues that recycled numbers are causing consumers.”

Which? advise that it makes sense for people to avoid changing their phone number wherever possible. If consumers are changing provider, for example in order to seek better customer service or a money-saving deal, they can still easily retain their existing number.