About 6.3m CTF accounts were set up between 2002 and 2011 with the government offering a £250 voucher to encourage initial take up.
An estimated £9bn+ is held in CTFs.
Over 700,000 accounts are now set to mature each year from September onwards as the holders turn 18.
HMRC says millions of teenagers will benefit for the first time from money in tax free Child Trust Funds.
From 1 September, as the oldest children turn 18 they will be able to access their money.
While CTFs were a government scheme the money has been held by CTF providers. The current tax free maximum investment per annum is £9,000.
The Government has set up a new online tool to help account holders find any CTFs they have lost track of as it believes some children may not know there are accounts in their name.
The tool can be accessed here: https://www.gov.uk/child-trust-funds/find-a-child-trust-fund
For those who do not have the identifying information required to access the tool, HMRC will provide alternative, non-digital routes to finding a CTF provider.
The accounts were set up to encourage “positive financial habits” and a saving culture among the young account holders and HMRC is working with the Money and Pension Service (MAPS) and the CTF providers to continue to provide financial education to the beneficiaries.
CTFs were praised as helping children from poorer families save but at considerable cost to the Treasury.
CTFs were originally set up for children born between 1 September 2002 and 2 January 2011 with a live Child Benefit claim. Parents and guardians received a voucher for at least £250 to deposit in a Child Trust Fund (CTF) account on behalf of an eligible child.
CTFs were replaced by Junior ISAs in 2011.
The average amount held in CTF varies between provider but one mutual said in 2018 that it’s average holding was just under £2,200.