Personal Finance: Insure your car with the stamp of approval.
The motor cover is the second product it has offered as part of its joint venture with the Bank of Ireland, which started earlier this year.
The group will act as a broker, getting quotes from more than 20 different insurers to get the best deal for customers, and it estimates that three out of four people will be able to get cheaper cover through it, saving an average of pounds 120 each.
It added it would not 'cherry-pick' customers and would give a quote to 99 per cent of motorists who applied.
David Mills, chief executive of the Post Office, said: 'Many consumers are not aware of the cherry-picking undertaken by insurance companies to provide the cheapest rates possible.
'Our new car insurance offering promises to quote for 99 per cent of consumers, reflecting the Post Office objective to provide simple, value for money products, which are accessible to everyone.'
Earlier this year the Post Office started offering personal loans through its partnership with Bank of Ireland.
The group previously offered motor insurance through a pilot scheme in the Midlands and said both the number of people asking for quotes and taking up the cover had exceeded its expectations.