Junior ISA Explained: Tax-Free Saving for Children

A Junior ISA is one of the simplest ways to build a tax-free nest egg for a child, giving them a financial head start they can access when they turn 18.

A Junior ISA (JISA) is a tax-free savings or investment account for a child under 18. A parent or guardian opens it, and up to £9,000 can be paid in each tax year by anyone. The child takes control of the account at 16 but can't withdraw the money until they turn 18.

In this insight we cover the £9,000 allowance, who can open and pay into a JISA, the difference between the cash and stocks and shares versions, and what happens as the child grows up.

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Key Takeaways

• A Junior ISA lets you save or invest up to £9,000 a year for a child, completely free of income and capital gains tax.
• The £9,000 allowance is separate from — and on top of — the adult £20,000 ISA allowance.
• A parent or guardian opens and manages the account, but the child takes control of it at 16 and can withdraw the money at 18.
• You can choose a cash JISA for security or a stocks and shares JISA aiming for higher long-term growth.

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How a Junior ISA Works

A Junior ISA locks money away for a child until adulthood, and everything inside it grows free of UK tax. There are two types:

• A cash Junior ISA, which works like a savings account and pays interest
• A stocks and shares Junior ISA, where the money is invested for potential growth

A child can hold one of each type at any time, but no more. The total paid across both in a single tax year can't exceed the £9,000 allowance.

Because the money can't be touched until 18, a JISA is genuinely long-term. That long horizon is one reason many families choose the stocks and shares version — over 18 years, investments have historically had time to ride out the ups and downs and potentially outpace cash.

The £9,000 Allowance

For the current tax year, up to £9,000 can be paid into a child's Junior ISAs. Importantly, this sits entirely separately from the adult £20,000 ISA allowance — so a parent can pay into their own ISAs and a child's JISA in the same year without one eating into the other.

The allowance resets each tax year on 6 April and can't be carried forward. Anyone can contribute — parents, grandparents, aunts, uncles and family friends — as long as the combined total stays within £9,000. That makes a JISA a popular home for birthday and Christmas money.

Who Can Open and Manage It

Only a person with parental responsibility for the child can open a Junior ISA — usually a parent, but sometimes a legal guardian. The child must be:

• Under 18
• Resident in the UK (or the child of a crown servant)

The adult who opens the account is called the registered contact and manages it on the child's behalf — choosing the provider, moving between cash and investments, and keeping details up to date. They can't withdraw money for their own use; it belongs to the child.

When the Child Takes Over

Two milestones matter as the child grows up:

• At 16, the child can become the registered contact and take over managing the account themselves — choosing where it's held and how it's invested.
• At 18, the account matures. The child gains full access and can withdraw the money, or roll it into an adult ISA to keep the tax benefits.

It's worth preparing a teenager for that moment, because at 18 the money is entirely theirs to spend. Our guide on raising financially smart children has ideas for building good money habits before then.

Can a child also open an adult ISA?

From 18, yes — that's when an adult cash or stocks and shares ISA becomes available. There's no adult ISA before then, so a JISA is the main tax-free route for under-18s. (16 and 17-year-olds could previously open an adult cash ISA too, but that door has been closing.)

Cash vs Stocks and Shares

Choosing between the two versions comes down to time and attitude to risk:

• Cash JISA — the balance won't fall, and you know where you stand. Best if the child is close to 18 or you want certainty.
• Stocks and shares JISA — the value can rise and fall in the short term, but over a long childhood it has more potential to grow ahead of inflation.

Many families with a young child lean towards investing for that longer runway, then consider shifting towards cash as 18 approaches. Our cash ISA vs stocks and shares ISA guide explains the trade-off in more detail, and you can model growth with our compound interest calculator.

Frequently asked questions

Can I open a Junior ISA if my child has a Child Trust Fund?

You can't hold both at once, but you can transfer a Child Trust Fund into a Junior ISA. JISAs generally offer better rates and wider choice, so it's often worth doing.

Who owns the money in a Junior ISA?

The child does. The parent or guardian manages it, but the money legally belongs to the child and can't be taken back or used by the adult. At 18 it's entirely theirs.

Can grandparents pay into a Junior ISA?

Yes. Anyone can contribute to a child's JISA, as long as the total from all contributors stays within the £9,000 annual limit. Only a parent or guardian can open and manage the account, though.

Does the £9,000 count towards my own ISA allowance?

No. The Junior ISA allowance is completely separate from your personal £20,000 adult ISA allowance, so paying into a JISA doesn't reduce what you can save in your own ISAs.

General information only, not financial advice. ISA and savings rules can change — check gov.uk before acting.