A quarter (24%) of ISA savers are not aware there is a tax deadline for their £20,000 ISA allowance, meaning some could be missing out on accruing tax-free interest on their savings, Charles Stanley has found.

Ahead of the deadline later this week, the investment manager’s survey revealed that 13% of those who have more than £20,000 in savings are not aware there is a tax deadline for their yearly ISA allowance.

Furthermore, 21% of those with savings between £15,001 and £20,000 are not aware of the ISA deadline, along with 25% of those who have a savings pot of between £10,001 and £15,000.

Charles Stanley said that the run up to the ISA deadline, known as ISA season, can have some influence over what people do with their savings.

When thinking about ISA season, 28% of ISA savers said it prompts them to top up their cash ISA so that their savings are protected, while 20% top up their investment ISA so their investments are protected from having to pay tax on them.

A further 17% said their financial advisers encourage them to contribute more into their ISA and 15% said their financial advisers sort their investments on their behalf, trusting them to have used their allowance.

Chief investment analyst at Charles Stanley, Rob Morgan, said: "ISAs have many benefits for savers and investors - they’re tax-efficient, easily accessible, can be used for short- and long-term goals, and can also be used as a bridge for retirement savings. They’re the Swiss army knife of financial planning and can be used for nearly everyone’s needs and priorities.

"Yet there are clearly many who don’t know about the ISA deadlines in place. This raises concerns over how many are taking true advantage of their ISA allowance to maximise their savings and build superior compound gains.

"With rumours having also floated around that the Chancellor could make changes to cash ISA limits, it’s even more important that consumers don’t let their savings sit idly and ignore this year's deadline."

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