BT is guaranteeing a minimum speed of 100MBps in its two new residential broadband packages.
The Ultrafast Fibre 1 package will offer download speeds of up to 152MBps for £54.99 per month, while the Ultrafast Fibre 2 provides up to 314MBps for £59.99 per month.
They also offer upload speeds of up to 29MBps and 49MBps respectively, with a minimum guarantee of 10MBps.
Consumers will be entitled to compensation of £20 if minimum speeds are not achieved, the operator said.
BT is achieving the speeds through a mixture of technologies including G.fast and FTTH, depending on availability.
The plan is available to over 250,000 homes.
BT had 20.5 million broadband customers at the end of September 2017, up 400,000 year on year.
Marc Allera, CEO of BT Consumer, said: “We are the first and only company to guarantee speeds of 100Mbps for our customers, even at peak times when people really need their broadband to deliver.
“Ultrafast technology is going to be a vital part of a transformation in the speed that our customers receive.”
The announcement follows the UK’s advertising regulator introducing new rules to crack down on misleading speed claims by broadband providers in November.
The guidance requires residential broadband providers to base numerical speed claims in advertisements on the download speed available to a minimum of 50 percent of customers at peak time.