Women risk being “overly cautious” as 82% opt to put entire ISA savings into cash, according to the authors of a report by MoneyFarm, a digital wealth management company.

Men are 20% more likely than women to use a Stock and Shares ISA, according to its analysis of HMRC data.

They said that nearly 6 million chose to put their ISA savings in cash alone when subscribing to an ISA in 2012/13 (the latest data available).

The overall ISA take-up was higher among women than men as they opted to take advantage of the tax-free savings accounts.

Paolo Galvani, chairman and co-founder of MoneyFarm, said: “A very real risk for cash ISA savers is that they could see the value of their savings eroded by inflation.

“While saving in cash is often seen as a ‘safer’ option, it is not always an appropriate strategy, particularly for those looking for long-term savings growth.

“Given that women are on average likely to live longer than men, this is a key consideration.

“With interest rates on cash ISAs so low, savers with cash products risk seeing real-term value reduce rather than rise over time.

“There’s a strong argument to say that women should look at a less cautious, risk-averse approach than men to maximise their savings since they are more likely to be relying on their savings to last longer.”

The firm cited Bank of England figures, which showed that the average interest rate offered by UK banks on cash ISA deposits is currently just 0.99%.

MoneyFarm is launching a new Stocks and Shares ISA which it claims “breaks the mould”.

This will focus on maximising value from structurally low cost investments such as Exchange Traded Funds to improve the potential return/cost ratio, it said.

Mr Galvani said: “ETFs are an exciting, yet remarkably under-explored, investment option for ISAs because they can help maximise diversification via many different markets and countless individual securities globally.

“We believe that such a strategy, combined with a pro-active, transparent approach, will inject some much-needed product differentiation into the ISA market.”