EE has confirmed a problem with 4G calling has left users unable to make phone calls.
The BT-owned telecoms giant had been contacted by a number of users of social media, who complained they had been unable to make or receive calls.
In a message sent to several customers who contacted the company on Twitter, EE said: “We’re aware that a small number of customers are unable to make some calls over 4G.
“We’re doing our best to fix this quickly. Please keep retrying and we apologise for any inconvenience. WiFi calling, as well as text and data services, are not affected.”
Service monitoring website Down Detector also confirmed a problem with EE and reported receiving complaints from users in several parts of the country.
The website said it received reports of issues from users in London, Birmingham, Nottingham, Manchester, Bristol, Liverpool and Leeds, which began just after 8.30am on Tuesday.
In a further statement, an EE spokesman said: “Some of our customers have experienced intermittent problems making calls on 4G this morning. This issue has been resolved for the majority of those affected and normal service for all customers should resume shortly.
“Calls over 3G, data services and text messages have not been affected, so customers have been able to get online and use apps and messaging services as normal. We apologise to our customers for the inconvenience caused.”