The EE phone network is down, leaving hundreds of customers struggling this morning.
Users have taken to social media to report the problem to the firm, claiming they are unable to make or receive phone calls.
Some have also said they are not able to send texts and have asked the tech giant when the problem will be fixed.
According to reports, the issue is affecting customers right across the UK, including Merseyside, the Midlands and London.
One user wrote: "No network in Derby, how long is this going to be down?"
Customers have been left without service this morning. Credit: PA
A second person then said: "@EE is your system down? Not letting me make a call? Keep saying call failed."
Another asked: "Is network down in Merseyside area ? Can't call."
Some have been demanding the company should 'sort the issue', with one irate user saying: "I don't pay a stupid amount of money for my network to be down!!!"
EE's social media team are currently responding to customers via Twitter, asking them to give details about what issues they are experiencing and where they live.
Replying to one user, they said: "I appreciate how important it is to stay in touch with your friends and family. I'd love to help here. Could you please send us a DM with your postcode, so we can check the area?"
The company has said a 'small number' of customers have been unable to make phone calls. Credit: PA
The firm has told some customers the issue is due to 4G coverage and that only a 'small number' of customers were experiencing problems with phone calls.
Responding to several users, the social media team 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."
It is not yet clear when the issue will be resolved.
Featured Image Credit: PA