Savers are losing out on a possible £12bn in interest payments by staying with low-rate accounts, according to research collated by Which?

The data showed that nearly half of 1,200 savings accounts in the UK paid interest of 0.5% or less. If all savers switched to accounts with the highest rates they could receive an extra £12bn a year.

"Whilst we pressure the banks to be more upfront about their rates, people can take action and potentially add hundreds of pounds a year to their savings by moving their money to a better account," said Which? chief executive Peter Vicary-Smith.

The British Bankers Association has said that details of savings rates are readily available to all individual and business customers.