Twenty five per cent of consumers have no idea of their cash ISA's interest rate and only 28 per cent "feel confident" they know their account's interest rate.
A quarter of ISA savers have no idea how much interest is attached to the cash-linked product.
Research conducted by ICM on behalf of the Cooperative banking group shows that while 92 per cent of ISA customers have such an account, only 28 per cent are confident they know the interest rate it pays.
However, as 25 per cent admit to having no idea the firm claims that as the financial year draws to a close consumers may not be making the best decision on where to transfer ISA accounts
Rod Bulmer, managing director for Cooperative Financial Services, said: "It is worrying that people have invested their money in a product but they do not know what the interest rate is."
The news follows the announcement that the tax-free savings threshold for ISAs
is set to increase. From April 6th consumers of all ages will be able to place up to £5,100 into cash ISAs each financial year.
By Nate Sawyer