BT broadband services across the country were disrupted on Friday morning by problems at an exchange in London.
The issue, which began at 8:30am and was resolved within 15 minutes, caused broadband supplier Plusnet to warn customers up and down the country of intermittent broadband connection loss.
"BT can confirm that a very small proportion of customers had technical issues with their broadband around 8:30am this morning," BT said in a statement on Friday. "This issue was quickly resolved in around 15 minutes. Affected customers are advised to restart their hub or router."
However, Plusnet was still finding it difficult to restore connectivity to customers after BT had dealt with the outage.
"Our suppliers have advised of a major service outage affecting users all over the country this morning," Plusnet wrote at 9:11am. "If you have been disconnected from the internet and are having problems getting back online then please switch your modem/router off for 20 minutes or so before powering it back up and attempting to reconnect."
Zen Internet warned customers at 8:40am that it needed to carry out emergency maintenance due to an issue affecting the BT Stepney Green exchange. "Our engineers are currently working with our supplier to resolve the problem," it said.
As of 11:10am Plusnet's automated broadband status line was reporting no known issues with the network.
"This does seem to be an extremely brief outage and all affected customers' [broadband] service was back up and running a couple of hours ago," a BT spokeswoman told ZDNet UK.
BT did not disclose the cause of the outage.