Research from Charter Savings Bank has found that more than two out of five (43%) didn't make the switch because they wanted all their money in one place, while 9% didn't transfer accounts because they felt it would be too complicated.

The main motivation for transferring cash Isa accounts from an existing provider was a rate reduction, with 51% of respondents who have switched reporting that they did so for this reason.

Just over a third of over-55s (35%) said they assessed the cash Isa offers each year and moved if they found a better rate.

One in three (33%) said they switched products when the fixed rate term on their cash Isa expired.

The group most likely to transfer cash Isas were those aged between 25 and 44, with 62% switching their cash Isas.

Paul Whitlock, director of savings at Charter Savings Bank, said: “Transferring cash Isa accounts is a straightforward process, now that the industry has signed up to new standards and is utilising new technology and systems.

“People regularly shop around for more competitive deals on a wide range of goods and services, and that should also be the case in the cash Isa market.

“Those who don't move are risking missing out on more competitive rates, greater flexibility and access to their savings when needed.

“The Charter Savings Bank mix and match Isa provides flexibility for savers and enables them to split their allowance across multiple accounts, all with competitive rates.”

Charter Savings Bank's mix and match Isa platform enables savers to spread their annual allowance in more than one cash Isa product at the same time.