4G calling means that when you make or receive a phone call, your phone will stay on 4G so your internet doesn’t slow down. That means you can use data at 4G speeds even when you’re on a call.
Customers have been complaining on Twitter, saying they have received alerts reading: “O2 has turned off 4G calls on your account”.
Jamie Gallagher said: “What does this notification mean please? Why have 4G calls been turned off?”
Another customer added: “Just had a notification to say you’ve switched off 4G calls on my account – why would this be?”
The problem occurred for some users in late February, while others started experiencing it over the weekend.
How can I turn 4G calls back on?
O2 says this notificant tends to pop up for customers who have had a data update for their device overnight, or when there has been a change in the network.
The operator said: “A device does this check against the network every time it’s restarted, and one is done at 24-hour intervals. It is not unusual for a user data update to require a device restart.”
O2 has responded to some of the people reporting the issue with a simple fix
First, you should switch your phone off and back on again.
Then, head to Settings > Mobile Data > Mobile Data Options > Voice & Data > VoLTE and check that 4G calling is enabled.