BT broadband is down across the UK, the company has said.
The internet provider's website has also crashed and many customers report the customer service line is down.
A BT 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."
Customers from around the UK reported problems with their internet and landlines on social media.
Keith Pestell tweeted: "BT internet down, support lines down and website down. I did get through to India and the lady said: It's working here... really?"