BT’s broadband and phone network appears to have been suffering nationwide problems in the UK.
Down detector, a website that monitors internet failures, is reporting thousands of cases in places such as London, Birmingham, Sheffield and Coventry.
There are also numerous reports on social media from customers experiencing issues.
BT confirmed that many of its services were currently not working.
A spokesman said: “It is true that we are down at the moment. We are aware of the problems and are working on them as fast as we can.”
Its website has also crashed and some users are reporting that its customer service line is down.
Hundreds of people have taken to social media to express their frustration using the hashtag #BTdown.