Banks and building societies have closed at an alarming rate in recent years, with over 5,800 branches shutting since 2015, the consumer group said.
Which? research indicates that 30 parliamentary constituencies, with an estimated population of 2.8 million people, will have no physical bank branches left by the end of this year.
Sam Richardson, deputy editor of Which? Money, said: “A closed bank branch isn’t just a high street eyesore, but one less place for consumers to go to withdraw cash or access in-person banking services.
“Which? research shows that millions of people could be without a local branch by the end of 2024 as banks continue to close at an alarming rate.
“Alternatives like banking hubs could help plug the gaps, but they are being rolled out too slowly, so more must be done to ensure communities get these replacements for their closed bank branches as soon as possible.”
A spokesperson for UK Finance, which represents the banking and finance industry, said: “An ever increasing number of people are using telephone, mobile and internet banking and fewer people are visiting bank branches on a regular basis.
“This means banks are having to make difficult decisions about the number of branches they operate. A decision to close one is never taken lightly and only happens after an extensive review of its usage and consideration of other options in the local area.
“The banking industry is committed to ensuring there is continued access to cash for those who need it, when they need it. Significant ongoing investment is being made to deliver this commitment, including shared banking hubs, free ATMs and cashback without purchase.
“There are 31 shared banking hubs open now across the country, with a further 70 scheduled to open later this year.
“There is also the option to do a lot of day-to-day banking at the Post Office, which has around 11,500 branches across the UK.”
Here are the constituencies identified by the consumer group which used census data to make population estimates:
Barnsley East
Bolton West
Bradford South
Central Suffolk and North Ipswich
Clwyd South
Colne Valley
Denton and Reddish
Don Valley
East Worthing and Shoreham
Erith and Thamesmead
Glasgow North East
Liverpool, West Derby
Mid Bedfordshire
Mid Derbyshire
Newport East
North East Derbyshire
Nottingham East
Penistone and Stocksbridge
Plymouth, Moor View
Reading West
Rhondda
Sedgefield
Sheffield, Hallam
St Helens North
Stone
Swansea East
Warrington North
Wentworth and Dearne
Wirral West
York Outer
