Santander has announced plans to close 111 branches across the country due to the shift to mobile and online banking.
The bank said it had taken the decision because fewer customers were choosing to bank in branch.
About 840 staff will be affected by the closures, although Santander promised to try to find them other jobs within the business.
Santander said the reduction in branch visits was a long-term trend that had been accelerated by the pandemic.
"Branch usage by customers has fallen considerably over recent years so we have made the difficult decision to consolidate our presence in areas where we have multiple branches relatively close together," said Adam Bishop, head of branches at Santander.
The move will reduce Santander's High Street presence to 452 branches.
But the bank said the majority of closing branches were within three miles of another Santander branch. The furthest is five miles, it said.
"All are within half a mile of at least two free-to-use ATMs and one mile of the nearest Post Office," it added.
In the two years before the beginning of the pandemic, the number of transactions handled in branches fell by a third, the bank said. Last year, it declined by a further 50%.
Meanwhile, mobile and online transactions have grown 20% each year with more than two-thirds of transactions now completed without customers visiting a branch.
The bank also plans to move its headquarters from London to Milton Keynes and reduce the amount of space it rents in the capital.
It will close offices in Bootle, Newcastle, London and Manchester before the end of the year.
The 5,000 office staff affected will be asked to work from home more often or travel in to one of its six remaining offices in Belfast, Bradford, Glasgow, London and Sheffield, as well as its new headquarters.
"The pandemic has accelerated the existing trend towards greater flexible working, and our colleagues have told us this has brought significant benefits for many of them," Santander's UK boss Nathan Bostock said.
"At the same time, physical spaces remain very important and our sites around the UK will provide our colleagues with first-class facilities fit for the future."
The decision to reduce the number of offices it rents and ask staff to work from home more often follows an announcement from building society Nationwide which told its 13,000 office staff that they could choose where they work.
Under the plan, Nationwide is closing three offices in Swindon, with 3,000 staff either moving to the nearby HQ, working from home, or mixing the two.