Phone network Three is down, with users unable to make or receive calls.
The nature of the outage means that users might not necessarily know that they are affected by the outage, since there is no way of knowing whether they are missing incoming calls.
As well as Three’s own customers, the outage also affected iD Mobile and Smarty, both of which rely on its network.
The problems appeared to be widespread across the country, according to tracking website Down Detector. It showed problems beginning on Monday morning.
Internet data appears to be working as normal, the network said.
“We're aware of an issue affecting voice services and are working hard to fix it,” the network said.
“Data services are working normally. Please accept our apologies for any inconvenience caused.”
It gave no information on what might have caused the problem or when it would be fixed, only that it is “working to resolve it”.
For landline and broadband accounts, Ofcom runs an automatic compensation scheme that pays out to customers when certain networks are offline. There is no such scheme for mobile networks such as Three – but customers have in the past been offered refunds in return for complaints over substantial outages.
