[Update: An O2 spokesperson has released the following statement: "We can now report that our 4G network has been restored. Our technical teams will continue to monitor service performance closely over the next few days to ensure we remain stable."
"A review will be carried out with Ericsson to understand fully what happened. We’d like to thank our customers for their patience during the loss of service on Thursday 6 December and we’re sorry for any impact the issue may have caused."
We will continue to update this story as more information becomes available and the original story follows below.]
O2 customers across the UK have been hit by a network outage that has left them unable to use 4G and data services, meaning they can't access the internet without a Wi-Fi connection.
Some users have also reported problems with making voice calls, despite claims from O2 that voice services are unaffected.
The issue has affected an estimated 32 million people, as O2 also provides services for Sky, Tesco, Lycamobile, and Giffgaff mobile networks. Telecoms data company Tutela has revealed that over 90% of users were affected, with 2G, 3G, and 4G connections all suffering as a result of the outage.
The problems were first reported at around 5:30am, with many users taking to Twitter to vent their frustration.
O2 internet down. I had to speak to someone on the train. This is a disgrace. #o2 #o2downDecember 6, 2018
Data network outage on the @O2 network and they've only informed customers via social media and their websites network status page. Great communication process when there's no mobile data, what ever happened to a simple SMS notification? #o2 #o2downDecember 6, 2018
O2 issued the following statement on its website: "Our technical teams are investigating reports of issues when using data. Voice calls are working OK. Our technical teams are investigating."
It seems the O2 network outage is linked to global problems with Ericsson software. The Swedish company told the BBC that it was "aware of an issue and is investigating."
However, some users are reporting that they're also unable to make voice calls or send text messages, so the full scope of the problem is unclear at present.
The network outage has also affected Transport For London, which uses the O2 network for its electronic timetable displays at bus stops.
That could make commuting across the capital particularly difficult with users of the O2 network unable to use 4G to plan their routes, and bus stop displays out of order.
If you are commuting this morning, it may be worth checking your journey before you leave the house – and don't expect to be able to send GIFS to your mates while you're on the train.