The Junior ISA: The £9,000 Allowance, the Age-18 Handover and HMRC's Numbers
A Junior ISA is a long-term, tax-free UK savings or investment account for a child under 18. Anyone can pay in, up to a total of £9,000 in the 2026 to 2027 tax year, the money belongs to the child, and it cannot be taken out until they turn 18, when the account becomes an adult ISA.
A Junior ISA is the UK’s tax-free account for children. It works like an adult ISA with three differences that decide whether it suits a family: a lower yearly limit, a lock until the child’s 18th birthday, and the fact that the money belongs to the child from the moment it goes in.
This page sets out the rules as GOV.UK states them, works through the shared allowance, then uses HMRC’s own statistics to show how families actually use the account and how that has changed since it launched in 2011.
How it works
Who can have one. GOV.UK says a child must be under 18 and living in the UK. A child living abroad qualifies only if a parent is a Crown servant, such as a member of the armed forces or diplomatic service, and the child depends on that parent for care.
Two types, one of each. There is a cash Junior ISA, where interest is tax-free, and a stocks and shares Junior ISA, where capital growth and dividends are tax-free. A child can hold one of each, but only one cash and one stocks and shares account.
Who opens and runs it. For a child under 16, only a parent or guardian with parental responsibility can open the account. That person becomes the registered contact and is the only one who can change the account type or provider. Children aged 16 and 17 can open their own, and from 16 a child can take over as registered contact.
Who pays in. Anyone can pay in: parents, grandparents, friends. The total from everyone cannot go over £9,000 in the 2026 to 2027 tax year, which runs from 6 April 2026 to 5 April 2027.
When the money comes out. Not before 18. GOV.UK names the exceptions: a registered contact can take money out early if the child is terminally ill, meaning not expected to live more than 6 months, and if a child dies the money passes to whoever inherits their estate.
At 18 it becomes an adult ISA automatically, and the young adult can take out any of the money. Money cannot be moved between a Junior ISA and an adult ISA before then.
Child Trust Funds sit alongside. Child Trust Funds are the older accounts for children born between 1 September 2002 and 2 January 2011, a scheme that closed in 2011. A child cannot have both, but a Child Trust Fund can be transferred into a Junior ISA.
A worked example
The £9,000 is one limit shared by both accounts and every person paying in. GOV.UK’s own example: if £2,000 goes into a child’s cash Junior ISA between 6 April 2026 and 5 April 2027, only £7,000 more can go into their stocks and shares Junior ISA in the same tax year.
Now add family members. Take a hypothetical child whose parents pay £100 a month into a stocks and shares Junior ISA:
- Parents’ payments over the tax year: £100 × 12 = £1,200.
- Room left for everyone else that year: £9,000 - £1,200 = £7,800.
- A grandparent who wants to give £8,000 can put in £7,800 this tax year. The other £200 has to wait for the next tax year or go somewhere else.
Across a childhood the difference in scale is large. Paying the HMRC average of £1,570 a year for 18 years puts in £28,260 in total. Filling a £9,000 limit every year for 18 years would put in £162,000. Both figures are money paid in only, before any interest or investment growth, and they assume the limit stays at £9,000, which is not promised.
Whatever the total, it becomes the child’s to spend at 18. A family that wants a say in how the money is used later, for example on university costs or a first home, cannot enforce that through a Junior ISA.
The original data
HMRC’s ISA statistics, released 16 Sep 2026, count Junior ISAs every tax year since they began on 1 November 2011. They count accounts that received money in the year, not every open account, and the latest year, 2024 to 2025, is provisional.
In 2024 to 2025, about 1.6 million Junior ISAs were paid into, up from 1.37 million the year before, with £2.519 billion in total. HMRC’s commentary gives the headline as “around 1.6 million” accounts and £2.5 billion. The average subscription was £1,570, up 16.6% in a year: £2,075 in a stocks and shares Junior ISA and £1,128 in a cash one.
The average is far below the limit. £1,570 is 17.4% of a £9,000 limit, so the typical account that received anything received less than a fifth of what it could have.
The shift to investing. In 2012 to 2013, the first full year, stocks and shares took 25.2% of the money paid into Junior ISAs: £99 million of £393 million, with £294 million in cash. By 2024 to 2025 they took 61.7%, £1.554 billion against £965 million in cash. Cash still had more accounts paid into, 856,000 against 749,000, because the average cash payment is smaller.
Growth in use. 296,000 Junior ISAs were paid into in 2012 to 2013, against 1.604 million in 2024 to 2025, 5.4 times as many. Every year is in the Junior ISA table, with the cash and stocks and shares split for both money and accounts.
What the accounts hold
At 5 April 2025, Junior ISAs held £14.111 billion, up 13.1% in a year: £8.396 billion in stocks and shares, 59.5% of the total, and £5.715 billion in cash. At 5 April 2013 the total was £557 million: £390 million in cash and £167 million in stocks and shares.
The balance between the two has not moved in a straight line. HMRC’s market value table shows stocks and shares holding more than cash at 5 April 2018, cash back ahead from 2019 to 2021, and stocks and shares ahead again from 2022. The tables give no reason for the swing in 2018 and 2019, and this page does not guess at one.
The older accounts are still large. HMRC’s commentary counts around 2.9 million open Child Trust Fund accounts at 5 April 2026. Around 827,000 of them had already matured and stayed open as Child Trust Funds, and around 415,000 more matured during 2025 to 2026 and were claimed or moved into an ISA.
When it fails
It fails a family that wants control after 18. The handover is automatic and complete. A US custodial account has the same feature, and the same trade-off.
It fails money that might be needed before 18. Apart from terminal illness, nothing comes out early, so a Junior ISA is the wrong home for a family’s emergency savings even if the account is in a child’s name.
A cash Junior ISA can fail over 18 years. A long lock-up in cash risks falling behind inflation, which is the case the cash ISA vs stocks and shares ISA comparison sets out for adults. A stocks and shares Junior ISA carries the opposite risk: its value can be down at the moment the child turns 18.
It can be lost track of. GOV.UK runs a free tool for finding a Child Trust Fund provider, and 827,000 matured Child Trust Funds were still open at 5 April 2026. A Junior ISA opened at birth needs its paperwork kept for 18 years.
And the limits can change. The £9,000 figure is set for the 2026 to 2027 tax year; any statement about future limits is a forecast, not a rule.
Related
The stocks and shares ISA is the adult account a Junior ISA becomes at 18, and the Lifetime ISA is the adult ISA built for a first home or retirement.
For US readers, the custodial account and the 529 plan are the nearest equivalents, one flexible and one tied to education. Compound interest explains why the early years of an 18-year account matter most.
Decide on the age-18 handover before deciding how much to put in. The account is built so that the child controls all of it at 18, so it suits money you are content to see them spend however they choose.
— Michael Whitman
This page is educational, not financial advice. Test every idea on your own charts before risking money.