Martin Lewis warns people born between 2002 and 2011 could be owed a share of £1.6 billion

People born between 2002 and 2011 could be missing out on thousands of pounds according to money expert Martin Lewis.

Lewis advised that at that time there was a tax-free savings account which was set up for children in the UK which could accrue value and then they could access it on their 18th birthday.

He explained that this was called a Child Trust Fund, and it was set up as a predecessor to the Junior ISA scheme, which is what is in use today.

This was a bank account which was set up and which the government would then contribute to, with parents also able to add in money of their own as well to increase the value of the pot.

Astonishingly, there are currently over 750,000 of these savings pots which are currently going unclaimed, with an average value of some £2,200, though he explained some would be higher and some would be lower.

Collectively, the pots contain a whopping £1.6 billion, great news for anyone who has an account.

Lewis advised people on how to find their account (Mike Marsland/WireImage)

"There are some that are missing out on thousands of pounds," Lewis said. "HMRC is currently writing to 21-year-olds, only 21-year-olds, about 750,000 of them, about unclaimed child trust funds.

"These were the predecessor to junior ISAs, and the state put money in for you. You could add on top, so everyone who has one has some money in it if they haven't taken it out."

He explained that HMRC's letter 'will tell you where your child trust fund is, so then you can go and contact that provider.'

"The average amount - two grand," he said. "But, it varies vastly depending on if the money was added by parents, and whether you saved or invested, because invested over a long period outperforms savings."

People who are born between September 1 2002 to January 2 2011 can also try and find their child trust fund right away without having to wait for the letter from HMRC.

People could be sitting on thousands of pounds (Jenner Images/Getty)

Explaining how to do it, he advised that people can go to gov.uk, where they will find the tool 'Find a Child Trust Fund'.

There are different rules for different ages, Lewis explained, so if someone is under 16 then their parent or guardian has to do it for them, over 18s have to do it themselves, and if someone is aged 16-18 then either they can do it themselves, or a parent or guardian can do it.

Nonetheless, Lewis also warned people about falling foul of crime while looking to claim their child trust fund, explaining that people will not call, text, or email them about it as it is a letter.

He said: "Just be careful scams, don't use details on there, go and find the company provider's details yourself and be careful of emails, calls, and texts. This is a letter."