The government is to reinvest £645 million recovered from BT into its 24Mbps superfast broadband rollout.
A contract clause between the two means that BT must refund money if enough people take up superfast broadband connections.
Take-up has proved to be higher than expected, which means BT has set aside £465 million to boost coverage over the full lifetime of the contracts across the UK.
A further £180 million has come about as a result of project efficiencies, meaning a total of £645 million is available for councils to reinvest in offering superfast speeds to homes and businesses that are not covered by existing plans.
The government believes that along with other planned rollouts, this could lead to more than 900,000 additional premises gaining access to superfast speeds by the end of the year.
Matt Hancock, the Digital Minister, commented: "We have now brought superfast broadband to almost 94 per cent of UK homes and businesses, and we are reaching thousands more every week.
"We are on track to reach 95 per cent by the end of the year, but we know there’s still more to do.
"The money that is now being returned to the programme for reinvestment will help us reach that final five per cent."
Mr Hancock added that the ultimate aim is to ensure 100 per cent of the UK can get affordable, fast and reliable broadband by 2020.
More than 4.5 million premises across the country have now benefited from the government's subsidised broadband rollout, while more than two million homes and businesses have signed up for superfast connections in locations where the government has invested in broadband.