What you need to know: Junior ISA (JISA): the complete parent guide
Quick answer: A Junior ISA (JISA) lets parents (and others) save up to £9,000 per child per tax year in a tax-free wrapper. The money is locked until the child's 18th birthday, at which point the child gains full legal control. JISAs come in two flavours: Cash JISA (interest-bearing, low risk) and Stocks &…
Key points:
- Eligibility: UK-resident child under 18 who doesn't have a Child Trust Fund (CTF — replaced by JISA in 2011).
- Opening: The parent with parental responsibility opens the account. The child can open their own from age 16.
- Withdrawals: No withdrawals until the child turns 18 (with rare exceptions for terminal illness).
A Junior ISA (JISA) lets parents (and others) save up to £9,000 per child per tax year in a tax-free wrapper. The money is locked until the child's 18th birthday, at which point the child gains full legal control. JISAs come in two flavours: Cash JISA (interest-bearing, low risk) and Stocks & Shares JISA (invested, potential for higher long-term returns). A child can hold one of each at any time. The £9,000 annual allowance is shared between them — not £9,000 in each.
The rules in plain English
- Eligibility: UK-resident child under 18 who doesn't have a Child Trust Fund (CTF — replaced by JISA in 2011).
- Opening: The parent with parental responsibility opens the account. The child can open their own from age 16.
- Contributions: £9,000 per tax year (2026/27 limit, unchanged since 2020/21). Anyone can contribute — parents, grandparents, friends — into the single JISA account. The total across all contributors counts toward the £9,000.
- Withdrawals: No withdrawals until the child turns 18 (with rare exceptions for terminal illness).
- Age 16–17: The child can manage the JISA but cannot withdraw funds.
- Age 18: The JISA automatically rolls into an adult ISA, fully under the child's control. They can withdraw immediately or keep it growing.
Cash JISA vs Stocks & Shares JISA
The Cash version pays interest (rate set by the provider). The S&S version invests in funds, ETFs, or other approved assets. For a long time horizon (18-year child has 0 years until age 18 — bad time horizon; newborn has full 18 years — best time horizon), the S&S JISA historically beats Cash JISA by 3–5% per year in real returns.
| Years to age 18 | Cash JISA (3% / yr) | S&S JISA (5% real / yr) |
|---|---|---|
| 1 year | +3% | +5% |
| 5 years | +16% | +28% |
| 10 years | +34% | +63% |
| 18 years | +70% | +141% |
For a child under 13, S&S almost always wins for long-term wealth. For a child 16+, Cash is more appropriate (volatility risk too high near withdrawal).
The age-18 transfer problem
At 18, the child has legal control over the JISA. They can withdraw the entire balance, spend it on anything, and there's nothing parents can legally do to stop them. For a JISA grown to £40,000+ by age 18, this is a meaningful concern.
Two ways to mitigate:
- Communication. By age 16–17, involve the child in conversations about long-term wealth. Many JISA holders choose to leave the money invested at age 18 and continue to use the ISA wrapper for adult life.
- Don't fund a JISA you'd regret. If you're saving toward a specific goal (university, house deposit) and want to retain control, a bare trust may be more appropriate.
JISA vs bare trust vs SIPP for children
JISA isn't the only way to save for a child. The three main options:
| JISA | Bare trust | Junior SIPP | |
|---|---|---|---|
| Annual limit | £9,000 | No limit (but gift IHT considerations) | £2,880 (grossed to £3,600) |
| Tax treatment | Tax-free growth + withdrawal | Child's tax allowance + bands apply | Tax-free growth, taxable on withdrawal |
| Control at 18 | Child has full control | Child has full control | Locked until age 57+ (rising) |
| Government top-up | None | None | 25% basic-rate relief |
| Best for | House deposit, university | Larger family wealth, flexibility | Long-term retirement seeding |
Many families use a combination: JISA for short/medium-term goals, Junior SIPP for ultra-long-term retirement seeding, bare trust for tax-efficient legacy wealth above the JISA cap.
Worked example — full £9k per year from birth
£9,000 a year into an S&S JISA, 5% real return, 18 years
| Total contributions over 18 years | £162,000 |
| Estimated growth (5% real, compounding) | ~£89,000 |
| Estimated JISA value at age 18 | ~£251,000 |
For a typical UK family, £9k/year per child from birth is unrealistic — that's £750/month. More common patterns: £100–£300/month, sometimes topped up by grandparents at birthdays. Even £100/month from birth (£21,600 contributions over 18 years) compounds to ~£35k at age 18 at 5% real returns.
Common mistakes
- Opening multiple JISAs of the same type. A child can only have one Cash JISA and one S&S JISA at any given time. Transfers between providers are allowed but you must close the old one first.
- Confusing the JISA limit with parental gifting limits. The £9,000 JISA limit is separate from the IHT gift allowance (£3,000/year). The JISA cap doesn't reduce IHT — it's an annual cap on tax-free saving, not an exemption from IHT on gifts.
- Forgetting to transfer Child Trust Funds. Children born 2002–2010 may have a CTF. Most banks have largely abandoned CTFs — performance and fees are typically poor. Transfer to a modern JISA provider.
- Investing in Cash JISA for a 0-year-old. 18 years of cash interest barely keeps pace with inflation. S&S is materially better for long horizons.
Sources and methodology
Rules and limits above follow HMRC's JISA guidance. Returns and projections use long-run historical UK equity returns (around 5% real per year over rolling 18-year windows). For a personalised calculation, see the LISA calculator (Lifetime ISA equivalent for over-18s). The methodology page documents sources.
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