The number of customers moving their current accounts from the big four banks to ones offering higher interest rates is accelerating.

Consumer magazine Which? estimates 3.5 per cent of people who have current accounts with Barclays, HSBC, Lloyds TSB and The Royal Bank of Scotland Group will change provider within the next year.

Which? estimates that people could collectively save up to £500 million a year by moving from the main High Street banks, which pay interest of just 0.1 per cent, to other banks which offer up to three per cent interest on balances.