The group said 50 M&S Bank branches will open in M&S stores across the UK over the next two years, with the first branch scheduled to open in July at its flagship Marble Arch store in London.
M&S added that current accounts will be made available from autumn 2012 and customers can pre-register their interest in July. Mortgages will be offered by the bank at a later date.
"Branches will be open twice as long as traditional high street banks; mirroring M&S store opening hours and enabling customers to bank while they shop, seven days a week," M&S said in a statement.
M&S already offers limited financial services through M&S Money, having first ventured into personal finance in 1985.