For most parents saving for a newborn or young child, a stocks & shares Junior ISA usually wins over the full 18–year horizon: history suggests investments tend to outgrow cash savings over long periods, and all growth is tax–free. A cash Junior ISA is the safer pick when the money is needed within a few years (say for a teenager near 18), because the balance can’t fall. Many families split the £9,000 allowance across both to balance growth and certainty.
Related reads: best children’s bank accounts and tax-free childcare.
What is a Junior ISA?
A Junior ISA (JISA) is a tax–free savings or investment account for a child under 18 who lives in the UK. The money belongs to the child, but the account is opened and managed by a parent or guardian with parental responsibility — known as the “registered contact”. Any interest, dividends or capital growth earned inside a Junior ISA is completely free of UK income tax and capital gains tax, and it does not count against the child’s or the parent’s own tax allowances.
There are two types: a cash Junior ISA, which works like a tax–free savings account paying interest, and a stocks & shares Junior ISA, which invests in funds, shares and bonds. A child can hold one of each at the same time, but cannot hold two of the same type. The whole point of a JISA is to lock money away for the long term — it cannot be touched until the child turns 18.
The 2026/27 Junior ISA allowance
For the 2026/27 tax year, the Junior ISA allowance is £9,000. That is the most that can be paid in across both the cash and stocks & shares pots combined — not £9,000 into each. The allowance resets at the start of every tax year on 6 April, and any unused allowance cannot be carried forward to the next year.
This Junior ISA limit is entirely separate from the adult ISA allowance of £20,000. A parent can therefore fund their own ISA up to £20,000 and still pay up to £9,000 into their child’s Junior ISA in the same year. You do not have to use the full allowance — you can pay in as little or as much as you like up to the £9,000 cap, whether as a lump sum, regular monthly contributions, or occasional top–ups.
Who can open and pay into a Junior ISA?
Only a parent or guardian with parental responsibility can open a Junior ISA and act as the registered contact. But once the account exists, anyone can pay into it — grandparents, godparents, aunts, uncles and friends can all contribute, which makes a JISA a popular home for birthday and Christmas money. The combined total from everyone still cannot exceed the £9,000 annual limit.
A child is eligible if they are under 18 and resident in the UK. Children born between 1 September 2002 and 2 January 2011 were instead given a Child Trust Fund (CTF), but those can be transferred into a Junior ISA — more on that below.
Control at 16, access at 18
Two ages matter with a Junior ISA. At 16, the child can take over as the registered contact and manage the account themselves — choosing providers, switching between cash and investments, and so on. However, they still cannot withdraw any money until they turn 18. At 18 the Junior ISA automatically becomes an adult ISA and the now–adult gains full access to the entire pot.
This is the key trade–off parents should understand: the money is genuinely the child’s, and at 18 they can spend it however they wish — on university, a first car, a house deposit, or anything else. There is no mechanism to restrict how an 18–year–old uses their Junior ISA. If keeping control past 18 matters more to you than the tax–free wrapper, a different savings vehicle may suit better.
Cash JISA vs stocks & shares JISA
The right choice depends almost entirely on time horizon and your comfort with risk. A cash Junior ISA pays a set rate of interest and the balance can never fall — ideal certainty, but the real value can be eroded by inflation over many years. A stocks & shares Junior ISA invests in the market: the value can go down as well as up in the short term, but over long periods investments have historically tended to outperform cash. The table below compares the two.
| Feature | Cash Junior ISA | Stocks & shares Junior ISA |
|---|---|---|
| Risk | Very low — balance cannot fall | Higher — value can go down as well as up |
| Typical return | Interest rate, often broadly 3–5% (variable, not guaranteed) | No set return; historically c.5–7% a year over the long run (illustrative, not guaranteed) |
| Tax on growth | None — interest is tax–free | None — dividends and gains are tax–free |
| Costs | Usually no fees | Platform and fund charges apply (often c.0.2–1% a year) |
| Best for | Short horizons or near–18 teens; the cautious | Long horizons (babies and young children); growth seekers |
| Access | Locked until 18; control at 16 | Locked until 18; control at 16 |
How compounding over 18 years favours stocks & shares
The longer the money stays invested, the more the case tilts towards stocks & shares. Compounding — earning growth on top of previous growth — is exponential, so even a modest difference in annual return becomes a large difference in pounds over 18 years. Short–term market dips also have time to recover when there is a decade or more before the child turns 18, which is why investing tends to suit babies and toddlers more than teenagers.
The chart below is purely illustrative. It assumes £50 saved every month (£600 a year, well within the allowance) for 18 years, comparing a cash rate of around 2.5% with an investment return of around 6% a year. These are assumptions for illustration only — actual returns will differ, are not guaranteed, and investments can lose value.
In this illustration you contribute £10,800 in total. At a 2.5% cash rate that might grow to roughly £13,600, while a 6% investment return might reach around £19,400 — nearly £5,800 more from the same contributions, simply because growth compounded over a longer period. Reverse the picture for a 15–year–old with only three years to go, and cash usually makes more sense because there is too little time to ride out a market fall.
Transfers and old Child Trust Funds
You can transfer a Junior ISA between providers, or switch between a cash JISA and a stocks & shares JISA, whenever you like — and you should always do this using the provider’s official transfer process rather than withdrawing the money, otherwise you lose the tax–free status. Transfers do not count against the annual allowance.
Children born between September 2002 and January 2011 hold a Child Trust Fund rather than a Junior ISA. A CTF can be transferred into a Junior ISA, which often means a better interest rate or lower investment charges. Note this is a one–way move: once transferred to a JISA you cannot switch back to a CTF. A child cannot hold both a CTF and a Junior ISA at the same time, so checking whether an old CTF exists is a sensible first step before opening a new account.
Choosing a provider: what to look for
For a cash Junior ISA, the headline figure is the interest rate — compare the AER across banks and building societies, and check whether the rate is fixed or variable and whether it includes a temporary bonus that drops away. Cash JISAs are typically free of charges and are protected by the FSCS up to £85,000 per banking licence.
For a stocks & shares Junior ISA, costs and fund choice matter most. Look at the platform’s annual account fee, the ongoing charges of any funds you pick, and whether there are dealing fees. A low–cost global tracker fund is a common starting point for long–term children’s investing, but the right mix depends on your circumstances. Rates and fees change constantly, so always check current figures directly with providers — never rely on a number quoted in an article as today’s deal.
Frequently asked questions
What is the Junior ISA allowance for 2026/27?
The Junior ISA allowance for the 2026/27 tax year is £9,000. This is the combined limit across both a cash and a stocks & shares Junior ISA — not £9,000 into each. The allowance resets every 6 April and cannot be carried forward if unused.
Can my child take the money out before 18?
No. Money in a Junior ISA is locked until the child turns 18, with only rare exceptions such as terminal illness. At 16 the child can take over managing the account, but they still cannot withdraw any money until their 18th birthday, when the JISA becomes an adult ISA they can access in full.
Is a cash or stocks & shares Junior ISA better?
It depends on the time horizon. For a baby or young child with many years until 18, a stocks & shares Junior ISA has historically tended to deliver more growth. For a teenager close to 18, a cash Junior ISA avoids the risk of a market fall just before the money is needed. Many parents use both.
Can I transfer a Child Trust Fund into a Junior ISA?
Yes. A Child Trust Fund can be transferred into a Junior ISA, often to secure a better rate or lower charges. Use the provider’s transfer process to keep the tax–free status. The move is one–way — you cannot switch back to a Child Trust Fund afterwards — and a child cannot hold both at once.
Do grandparents have to pay tax on Junior ISA contributions?
No. Anyone can pay into a child’s Junior ISA — including grandparents — and all growth inside the account is tax–free. Only a parent or guardian can open the account, but contributions from family and friends count towards the same £9,000 annual limit. Large gifts may have inheritance tax implications for the giver’s estate.
Last reviewed: June 2026. This article is general information, not personal financial advice. A stocks & shares Junior ISA puts capital at risk — investments can go down as well as up and your child may get back less than was paid in. Figures shown are illustrative assumptions, not guarantees. Check current rates, fees and rules with providers and gov.uk before deciding.