All of its financial products will be brought under Post Office Money, which will have a presence within Post Offices on the high street.
The Post Office says that Futurebrand is working on branding and Edge is leading retail design.
The new brand is underpinned by a relationship with the Bank of Ireland and has already opened at the Islington London branch.
Post Office Money will appear in 300 branches and is rolling out now. The other 11,200 branches will promote and support the new service and feature communications designed for this purpose.
The Post Office says its research highlights that “choice of access remains a big factor when choosing a financial provider, with 30 per cent of the population looking for convenient branch locations or a high street presence when choosing a financial provider.”