BT landline-only customers will save more than one-third each year on their line rental bill, Ofcom has announced.

Up to one million customers will see their monthly bills cut by £7 after the telecoms giant agreed “in full” to a proposal made by the UK’s communications regulator.

This adds up to an annual saving of £84 – a 37 per cent reduction from a typical yearly bill.

Ofcom said it had conducted a review of the market due to concerns over line rental prices rising despite a fall in wholesale costs.

It recommended BT cut its monthly bills by between £5 and £7, which the company agreed to “in full”. The move will benefit thousands of elderly callers without broadband.

Nearly two-thirds of BT customers who only have a landline are over the age of 65. A customer who currently pays £18.99 a month will pay £11.99 when the changes come into force in April 2018.

This will return line rental prices to a similar level to those charged in 2010, Ofcom said.

The majority of affected customers – around 800,000 – will see the reduction appear automatically on their bills.

A BT spokeswoman said: “We welcome a balanced voluntary agreement with Ofcom which means that up to one million of our customers who don’t have broadband will receive a substantial cut in the price of their line rental.

“We have listened to the concerns of our line-only customers and agreed to reduce the price of line rental for them by £7 a month, or £84 a year.”