Millions of mobile phones will become "obsolete" when O2 makes a major change in just a few weeks. The provider is switching off its 3G network from April, affecting customers who use older phones.

It is the mobile network service used by millions of people around the UK. But O2 has now issued a warning to customers ahead of a major change that will stop some phones from working. The UK's 3G ...

Major changes are underway across the UK as Britain's 3G mobile network is consigned to history. This ageing technology, which first launched back in 2003, has already been decommissioned by companies ...