HSBC says it will close 114 more branches in the UK from April, as customers using them have fallen significantly since the pandemic.
The bank said it would try to redeploy affected staff but about 100 will lose their jobs.
Banks have closed thousands of branches in recent years as more people bank online and lenders cut costs.
HSBC said it would invest in updating its remaining 327 branches, but a union accused it of abandoning customers.
"Without any corporate social responsibility to require banks to stay on our high streets to help the elderly, disabled or vulnerable, then access to cash and banking will be lost forever," said Dominic Hook, national officer at Unite.
Jackie Uhi, HSBC's managing director of UK distribution, said people were changing the way they bank and footfall in many branches was at an "all-time low, with no signs of it returning".
"Banking remotely is becoming the norm for the vast majority of us," she added.
She said the decision to close a branch was "never easy or taken lightly", especially if it was the last branch in an area.
She added that HSBC was investing in "post-closure" measures, such as providing free tablet devices to help some branch customers bank digitally.
