The bank said it is because customers prefer digital banking, especially in the wake of coronavirus, although 90% of them had already been in touch with the bank via phone or internet in the past five years.
In fact, the number of customers using branches was down by a third since 2015.
The move is not expected to result in job losses as staff will be moved to nearby branches, with 511 sites left after the restructuring.
Some of them may offer reduced services, for instance by focusing on cash access, while the bank is considering ‘pop-up’ branches in some areas.
"The Covid-19 pandemic has emphasised the need for the changes that we are making,” Jackie Uhi, HSBC UK's head of network, was reported as saying by the BBC.
"It hasn't pushed us in a different direction but reinforces the things that we were focusing on before and has crystallised our thinking. This is a strategic direction that we need to take to have a branch network fit for the future."
Shares rose 2% to 411.95p on Tuesday afternoon.