Barclays, Natwest, HSBC, Lloyds and Halifax will all be closing branches across the country this year.
In recent weeks, Barclays announced the closure of 15 branches, NatWest said it is closing 23 branches and Lloyds Banking Group said it is shutting 40 Halifax and Lloyds sites.
Jenny Ross, Which? money editor, said: "While many consumers have embraced digital banking, there are still millions, including the elderly, vulnerable and isolated, who aren't yet ready or willing to make that switch - and they must be protected.
