13 million people urged to make a difference to claim a share of £18 billion

According to the analysis, more than £366 billion is languishing in UK current and savings accounts that earn returns of 1% or less. In January, Yorkshire Building Society and data consultancy CACI estimated there was £380bn held in accounts paying 1% or less.

According to new research by the organisations, this total has fallen slightly, meaning there are still believed to be more than £366 billion in low paying accounts. Almost a fifth (17%) of people admit they have never checked what interest rate they are earning on their savings, according to an Opinium survey for Yorkshire Building Society.

Over a third (36%) admit to keeping their savings in a checking account. CACI’s analysis shows there are still almost 13 million current accounts held in the UK with balances of more than £5,001, and of those people who hold at least £5,001 in their current account, the average balance held is £23,700.

According to the money-saving expert, Yorkshire Building Society offers a savings rate of 4.8% on an account that can be opened online for just £1 and allows unlimited withdrawals. It also lists Chase’s app-based 5.1% interest account among “what we’d pick.”

An interest rate of 5% on £366 billion would result in an interest payment of £18 billion over a year.

Chris Irwin, director of savings at Yorkshire Building Society, said: “Despite the attention savings interest rates continue to receive following significant increases in base rate (Bank of England base rates), it is surprising that they continue to there are such large pockets of people who are significantly losing interest on their savings. We started the year by pointing out that keeping large sums of funds in low-paying checking accounts has become a costly mistake for millions.

“It’s encouraging to see that for a small number of people they’ve made moves to improve the situation, however, there’s still an incredible amount of money that’s not making the return it could be.” Rachel Springall, financial expert at Moneyfactscompare.co.uk said: “Consumers will have different reasons for saving and how, but it’s essential to check that their account is paying a decent interest return on their hard-earned cash.

“Loyalty doesn’t always pay, and the convenience of keeping cash in a checking account means many savers receive little or no interest. Interest rates have changed considerably over the past 12 months, but if one doesn’t switch proactively, they could lose money in real terms due to inflation.”

Opinium Research surveyed 2,000 people in the UK in May.