There is now £721 billion of “dead money” sitting in the bank accounts and ISAs belonging to British adults, according to research.
The findings of Nutmeg Savings claim the average Brit aged 18 and over has saved £14,049.30.
However, it is also claimed that those sitting on the cash have no plans for it.
More than 70 per cent of 2,000 people polled said their savings are for a rainy day, and more than half admit they “don’t really know” why they have the money put aside.
One in 10 has an old Post Office or current account which was opened for them as a child, containing an average of £293.35.
And 39 per cent of adults have an old pension pot from a previous job worth more than £16,000 – but the majority have no idea how to access the money.
Meanwhile, a third of British adults also have up to £250 in cash stashed in their own homes, while one in 10 has over £1,000 tucked away.
And one in five has a personal pension containing more than £20,000, which they no longer pay into.
Lisa Caplan, head of financial advice for Nutmeg, said: “As this survey shows, people are sitting on their money, with no real plans on how to spend it, save it, or invest it.
“While saving money is obviously a sensible thing to do, there are ways of being even cleverer with cash.
“A large amount of people tend to assume just popping money into the bank makes the most financial sense.
“But with few accounts offering ways of increasing that sum of money, that might not be the case.
“Sometimes making a few wise decisions with money, such as investing, can really pay off.”