BT today admitted a power failure at a major exchange in Birmingham has left many without broadband.
Reports have suggested there were problems for businesses and consumers across the UK, stretching as far as Belfast and Cornwall.
BT said most services had been restored, claiming for the majority of customers the outage would have only lasted an hour.
"We can confirm that, as a result of a power failure at one of our major exchanges, some customers may currently be experiencing loss of broadband service," BT said.
"Our engineers are on-site and the majority of customers' service has already been restored. We are working to restore service to remaining customers as soon as possible this afternoon. Should any customers continue to experience difficulty in accessing their broadband service, they are advised to turn their hub or modem off and on again."
Many have taken to Twitter to vent their frustration at a lack of services, some complaining BT has not been answering its helpline.
Even comedian Richard Herring decided to post about the problems, tweeting: "BT confirmed massive broadband outage causing problems for most of their customers. Sounds like business as usual."
As with any ISP, BT has had to deal with its fair share of broadband outages. The last significant one was in November 2010, when thousands reportedly lost connectivity due to a fault in a switch at an exchange in the Edinburgh area.
