Initially it aims to launch the service in its Marble Arch branch, with plans to expand to up to 50 outlets before the end of the year.
Starting with current accounts, it is thought that the firm could expand its services to include mortgages. Branches would be open during shop hours – including Saturdays and Sundays – according to trade magazine Retail Week.
M&S Money, owned by HSBC, already offers services including credit cards.
Marks & Spencer declined to comment last night.