Marks & Spencer's first bank branch is to open with customers able to use it as late as 11pm as well as on Sundays.
The branch at its flagship Marble Arch store is the first of 50 planned to open over the next two years, with opening hours mirroring those of the stores they are sited in, meaning seven days a week banking.
The Marble Arch store regularly opens until 11pm on weekdays and those behind the venture said the new bank will be open during these hours.
M&S has also announced details of its first current account, which charges fees of up to £240 a year in return for "transparent" terms and a range of in-store perks.
The company, which expects to create 500 UK jobs from the roll-out of the M&S Bank business, will offer mortgages at a later date.
The launch of a new player in the market comes as mainstream banks are battling to win back customers' confidence in the wake of NatWest's IT chaos and Barclays' Libor-fixing scandal.
The retailer already provides credit cards, loans and savings to more than three million customers under M&S Money, which is run as a joint venture with HSBC.
Branches are expected to have a more relaxed, feminine appearance than the traditional high street banks, and the chain hopes to build on its reputation among its devoted followers as one of the high street's most trusted brands.
The retailer has produced a mock-up of how its M&S Bank branches will appear, featuring curved walls, a red and light grey colour scheme, a large area where padded armchairs are arranged to face each other informally and signage with the same design features as those already used in its stores.
M&S chief executive Marc Bolland said previously: "This bank will be built on M&S values, putting the customer at the heart of the proposition and delivering the exceptional service that sets us apart from the competition."