Junior ISA (JISA) UK 2025/26: £9,000 Tax-Free Allowance, Rules and Best Providers for Your Child's Future

A Junior Individual Savings Account is a long-term, tax-free savings or investment account for UK-resident children under 18. Interest, capital gains, and dividends inside the JISA wrapper are completely free from UK tax — no need to declare anything on a tax return.

The annual subscription limit for the 2025/26 tax year (6 April 2025 to 5 April 2026) is £9,000. This is separate from the adult ISA limit of £20,000, so a family can shelter up to £29,000 per year tax-free between a parent's ISA and their child's JISA. Anyone can contribute — parents, grandparents, family friends, the child themselves — provided the total stays within £9,000.

Two types exist:

• Cash Junior ISA — works like a savings account. For parents who prefer cash, notice savings accounts can complement a cash JISA with higher rates. Interest is tax-free. Capital is protected (up to £120,000 per institution under FSCS).
• Stocks & Shares Junior ISA — money is invested in funds, shares, or bonds. Capital gains and dividends are tax-free, but the value can fall.

A child can hold one of each type simultaneously, sharing the £9,000 limit between them. For example: £3,000 into a cash JISA and £6,000 into a stocks & shares JISA in the same tax year.

The money belongs to the child. A parent or guardian with parental responsibility opens and manages the account, but the funds are legally the child's property. At 16, the child takes control. At 18, the JISA automatically converts into an adult ISA and the money becomes accessible.

Two conditions, set by HMRC:

1. The child must be under 18
2. The child must be resident in the UK (exception: children of Crown servants posted overseas)

Only a parent or guardian with parental responsibility can open the account. Once open, anyone can contribute — grandparents are the most common additional contributors, and JISAs make an effective vehicle for birthday and Christmas gifts with a clear long-term purpose.

The Child Trust Fund rule. A child cannot hold a JISA and a Child Trust Fund (CTF) simultaneously. Children born between 1 September 2002 and 2 January 2011 were automatically enrolled in CTFs by the government. If your child has a CTF, it must be transferred to a JISA before a new one can be opened. Most providers handle the transfer, it takes around 30 days, and there is no tax charge. With the 5 April deadline just days away, a CTF transfer started now would not complete in time for this year's allowance — but starting the process means the JISA will be ready for 2026/27 contributions from 6 April.

The JISA allowance resets on 6 April each year. Unused allowance cannot be carried forward.

The right choice depends almost entirely on one factor: how long until the child turns 18.

For younger children with a decade or more ahead, a stocks & shares JISA has the stronger historical case. UK equities (FTSE All-Share) have delivered average annual returns of around 7–8% over 18-year rolling periods, comfortably beating cash even at today's relatively attractive rates. The long time horizon smooths short-term volatility.

For teenagers approaching 18, cash offers certainty. The best cash JISA rates as of March 2026, per MoneySavingExpert:

• Leek Building Society: 3.85% AER (post/branch only)
• Coventry Building Society: 3.75% AER (post/branch)
• Danske Bank: 3.75% AER (phone/branch, can manage online)
• NS&I: 3.55% AER (online, backed by HM Treasury)

A practical split: invest for the long term, save in cash for the short term. A five-year-old's JISA has 13 years of compounding ahead — stocks & shares. A 16-year-old's JISA needs certainty — cash. Some families do both, putting core savings into investments and a smaller buffer into cash.

Over 18 years at the full £9,000 annual contribution, the gap between cash and equities could exceed £90,000. That gap represents the opportunity cost of playing it safe with a very long time horizon. For more on choosing between ISA types, see our stocks & shares ISA vs cash ISA comparison.

Focus on three factors: fees, investment choice, and ease of use. For cash JISAs, the interest rate matters most. For stocks & shares JISAs, the platform fee compounds over 18 years — even 0.25% annually eats significantly into returns.

Stocks & Shares JISA platforms (data from MoneySavingExpert, March 2026):

• Hargreaves Lansdown — £0 platform fee, no dealing charges on JISA. The UK's largest platform with an extensive fund range. Hard to beat on cost for JISAs specifically. Min £100 lump sum or £25/month.
• Fidelity Personal Investing — £0 platform fee on JISAs. Strong fund range including low-cost index trackers. £1.50 dealing charge for regular savings plans. No minimum.
• AJ Bell — 0.25% annual fee capped at £2.50/month for shares. £1.50 fund dealing, £5 share dealing. Good value with a user-friendly app. See our AJ Bell review for the full breakdown. Min £250 or £25/month.
• Vanguard Investor — 0.15% annual fee. Limited to Vanguard's own funds but these are among the cheapest available. Ideal for simple index investing.
• Interactive Investor — Flat monthly fee structure. Access to a wide selection of funds, investment trusts, and shares.

For Cash JISAs, building societies dominate. Leek Building Society leads at 3.85% AER but requires post or branch access. For online convenience, NS&I at 3.55% AER is backed by HM Treasury — no FSCS limit applies. Always check current best-buy tables before opening, as rates shift frequently.

At £9,000 invested, the fee difference between Hargreaves Lansdown (£0) and AJ Bell (£22.50/year capped) looks small. Over 18 years with growing balances, however, percentage-based fees on AJ Bell and Vanguard scale up while HL's JISA remains free. For a pure cost comparison across ISA types, see our ISA platform comparison.

Opening a JISA takes minutes online with most providers. Here is the practical checklist:

What you need:

• Child's full name and date of birth
• Parent or guardian ID (passport or driving licence)
• National Insurance number of the registered contact
• Child's birth certificate (some providers request this)

The 5 April deadline:

The account must be open and funded by 5 April 2026. Most providers process applications within one to two working days, but bank transfers can add another day. Starting today (2 April) gives just enough margin — leaving it to 4 April risks missing the window if verification delays occur.

If you already have a JISA open, check the running total before topping up. The £9,000 limit includes contributions from all sources — if grandparents have already paid in, verify the remaining headroom to avoid accidentally breaching the cap. Contributions above £9,000 will be rejected by the provider.

The JISA limit is completely separate from the adult ISA allowance. Contributing to your child's JISA does not reduce your own £20,000 entitlement. Both allowances reset on 6 April, neither carries forward. For adult ISA planning, see our ISA deadline strategies guide and the ISA hub.

At 16, the child takes control of their JISA — choosing investments, switching providers, moving between cash and stocks & shares. They still cannot withdraw money. The parent or guardian loses management control at this point.

At 18, the JISA automatically converts into an adult ISA. The full balance is accessible, and the young person receives their own £20,000 adult ISA allowance on top. No tax is due on withdrawals because the ISA wrapper has shielded everything throughout.

The JISA balance does not count towards the child's £20,000 adult ISA allowance for that tax year. They can contribute a further £20,000 on top of whatever the JISA converts into. This makes the JISA-to-adult-ISA transition one of the most tax-efficient moments in a young person's financial life.

A child turning 18 with a substantial JISA faces a real financial decision. The best outcome is a young adult who understands what compound growth has done and chooses to keep the money invested. Starting a JISA is not just about the money — it is about creating a visible, growing pot that teaches financial literacy by example.