SANTANDER UK has announced it is to shut 140 branches, placing 1,270 jobs at risk.
A number of Scottish branches are among those earmarked for closure.
The bank said its decision was the result of more customers banking on digital platforms and becoming less reliant on physical branches.
The company says it hopes to redeploy around a third of the number of staff affected and that unions have been consulted on the proposals.
Susan Allen, Santander’s head of retail and business banking, said: “The way our customers are choosing to bank with us has changed dramatically in recent years, with more and more customers using online and mobile channels.
“As a result, we have had to take some very difficult decisions over our less-visited branches, and those where we have other branches in close proximity.
“We will support customers of closing branches to find alternative ways to bank with us that best suit their individual needs. We are also working alongside our unions to support colleagues through these changes and to find alternative roles for those impacted wherever possible.”
Following the closures by the end of the year, Santander will retain a network of 614 branches with its customers also having the option to bank using the more than 11,000 Post Office sites across the UK.
According to consumer group Which?, nearly two thirds of the UK’s bank branch network has been lost over the past 30 years.
Banks and building societies had 20,583 branches in 1988 according to parliamentary records, but the consumer group’s analysis of current account providers suggests the figure has dwindled to 7,586 branches.
The big high street lenders such as Royal Bank of Scotland and Lloyds Banking Group are also closing stores to deal with customers’ changing banking habits and to reduce costs as well as deal with the challenge from new digital only banks such as Starling and Monzo.
However, the branch closures is also seeing people having to travel long distances in order to access financial services and cash.
Santander also announced that it will spend £55 million refurbishing 100 branches over the next two years in order to “focus on personal service, convenience and community engagement”.