What happens to my child's Junior ISA when they turn 18 in 2026/27?

Full answer

A Junior ISA (JISA) is a long-term, tax-free savings or investment account for under-18s, with a 2026/27 contribution limit of £9,000 per tax year. Until the child turns 18, only a parent or guardian can manage it and the money cannot normally be withdrawn. From age 16 the child can take over managing the account, but still cannot access the cash. When the child turns 18, the account automatically converts into a standard adult ISA. No action is needed from the provider for the conversion itself, and the money stays sheltered from tax throughout. Crucially, your child now has full legal control: they can leave it invested, withdraw the whole balance, or transfer it to a different ISA provider. Parents have no further say, so it is worth discussing plans beforehand. From the 18th birthday the £9,000 Junior ISA limit is replaced by the adult ISA allowance of £20,000 per tax year, which can be split across cash, stocks and shares, and innovative finance ISAs. If your child is saving towards a first home or retirement, they could open a Lifetime ISA (must be opened between 18 and 39), paying in up to £4,000 a year and earning a 25% government bonus — but note the £4,000 counts within the overall £20,000 limit. A maturing JISA can be transferred into a LISA, though only £4,000 of it can go in each year. Interest and growth inside the ISA remain tax-free, so there is no Personal Savings Allowance issue and no Capital Gains Tax on investment gains. ISAs work identically across England, Scotland, Wales and Northern Ireland, as the rules are set UK-wide by HMRC rather than the devolved governments. There is no tax penalty for withdrawing once the account is an adult ISA.

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