At least £90bn is sitting dormant and unclaimed in over 30 million UK pensions, savings accounts, insurance policies and investments.

Of that £90bn, at least £64bn is sitting in pension savings, according to Gretel, a platform helping Brits find their lost accounts and investments which has partnered with some of the UK’s largest pension providers, among which is Aviva, to help reunite people with their cash.

Gretel estimates 27.2 million people in the UK have lost a savings, pension or shares account, with an average value of over £3,000.

It says a third of UK adults will have lost a pension and or a bank account, savings account, life insurance policy, investment, and Child Trust Funds (CTF).

Gretel estimates 2.8 million pensions with a combined value of £64bn, an average value of £23,125 each, are currently unclaimed.

Duncan Stevens, chief executive of Gretel, said the company managed to reunite savers with more than £10m in just over a week after featuring on ITV’s evening news programme Britain’s Hidden Fortune in the summer.

He said: “We are hoping to help savers track down their missing cash. That’s why we set up Gretel. It’s not just old savings accounts but with pensions auto enrolment, which means employers have to set up a new pension for all their employees, there are likely to be lost pots which go missing.”

“While it may just be the tip of the iceberg when you consider the entire financial services landscape, there is still a staggering £2.2bn sat unclaimed in Child Trust Funds in the UK.

“For many children, CTFs were set up at birth and long forgotten during the 18 years until they matured. When you add the potential for house moves and other life changes, it’s easy for people to lose touch with them. We want to get the money from ‘lost’ Child Trust Funds back to the younger generation where it could make a huge difference to their lives.”

A further £4.5bn is languishing in 14 million ’lost’ bank and building society accounts, the average value of each is £321.

Around £2.5bn in securities – shares, bonds and exchange traded funds – are unclaimed in two million accounts; each one worth an average of £1,250.

Lost investments, which includes endowment policies taken out to sit alongside an interest-only mortgage, total £2.8bn or £2,800 each.

Life insurance accounts for another unclaimed £8.1bn; this is sitting in 3.5 million accounts with an average of £2,380 each.

This figure is likely to include some annuities with a guaranteed death benefit, which would continue paying out if the original pensioner died.

Other lost cash includes £81m lying unclaimed in NS&I accounts, with an average of £35 lost while Child Trust Funds (CTFs) totalling £5.7bn and belonging to 2.6 million children – £2,175 each – is also lost.

Gretel’s free tracing service is available at www.gretel.co.uk. You can also use the government’s own Pension Tracing Service.