BT has confirmed it will scrap 20,000 unused phone boxes across the UK over the next five years amid falling demand and high maintenance costs.

The telecoms giant plans to remove 13,400 of its 40,000 BT public phone boxes over the next three years, with a further 6,600 set to be scrapped by 2022.

BT said it has seen usage decline by more than 90% in the past decade, while maintenance costs hover at around £6 million per year.

More than half of payphones are loss-making, and although the kiosks are used to make around 33,000 calls every day, that figure has been falling more than 20% year-on-year.

The number of public payphones peaked in 2002 at 92,000, but now less than 30,000 are used more than once a month.

A BT spokesperson said: “BT is committed to providing a public payphone service, but with usage declining by over 90% in the last decade, we continue to review and remove payphones which are no longer used.

“In all instances where there’s no other payphone within 400 metres, we’ll ask for consent from the local authority to remove the payphone. Where we receive objections from the local authority, we won’t remove the payphone.

“Payphone removals are carried out in strict adherence to Ofcom guidelines and, where appropriate, with the consent of local authorities.”

Nearly 7,000 of BT’s phone boxes bear the traditional red design, some of which could be in line for public protection as 2,400 of which are already designated as Grade II listed buildings.

But BT has also been encouraging communities to preserve their own part of Britain’s heritage by buying unused kiosks from the company for just £1 under the Adopt a Kiosk scheme.

More than 4,300 kiosks have been adopted and transformed into art galleries, mini libraries, exhibitions and information centres.

BT also assured that it was working to reinvent the traditional phone box, saying it was “in conversations with other cities to ensure the next generation of payphones is fit for the digital age”.