Martin Lewis has warned that some 21-year-olds are missing out on thousands of pounds due to unclaimed child trust funds (CTFs).
A CTF was a form of tax-free savings account available to children born between 1 September 2002 and 2 January 2011. They were the predecessor to junior ISAs.
The government contributed funds towards them, and children could withdraw money from their 18th birthday.
The Money Saving Expert founder has explained that more than 750,000 CTFs are unclaimed and likely holding a total of at least £1.6bn (approximately £2,200 each).
HMRC is now writing to 21-year-olds, informing them where their CTR is and how to claim their savings.
Lewis urged claimants to be aware of scams, as HMRC will only send a letter about CTFs and will not get in touch by email, phone call, or text.