O2 4G down: Data and network not working due to software issue, as Tesco Mobile and GiffGaff users also face outage

The Independent 

O2 has finally explained why its customers have been without internet for hours. The phone network has blamed a software problem at one of its suppliers, suggesting that the issue could be affecting other carriers too. Customers of O2 – as well as other networks that rely on its infrastructure, like GiffGaff and Tesco Mobile – have been unable to get online since early in the morning. Phones simply cannot connect to the internet and there is very little their users can do. There appears to be very little progress with fixing it.