Junior ISA explained: a parent's guide
If your teenager has started asking about "the stock market" — maybe because their friends are competing on a trading app, maybe because they've seen a stock ticker on TikTok — there's a good chance you've also started wondering: should we actually be investing for them?
In the UK, the answer usually starts with a Junior ISA. It's the single most tax-efficient way to invest on behalf of a child, but the rules around who controls it, when they can touch it, and how it fits alongside "practice" investing apps are rarely explained clearly. Here's the honest, no-jargon version — written for the parent, not the teenager.
What a Junior ISA actually is
A Junior Individual Savings Account (JISA) is a tax-free savings or investment account for anyone under 18 living in the UK. Like adult ISAs, any growth or income inside it is free from UK Income Tax and Capital Gains Tax. There are two types:
- Junior Cash ISA — works like a savings account: interest, but no market exposure or growth beyond the interest rate.
- Junior Stocks & Shares ISA — the money is invested in funds, ETFs or shares, so it can grow faster over 10+ years, but it can also fall in value.
A child can hold one of each type at the same time, as long as combined contributions stay within the annual allowance. Only a parent or legal guardian can open a JISA, but once it exists, anyone — grandparents, aunts, family friends — can contribute to it.
Who actually controls the money
This is the part that surprises most parents. The child legally owns the Junior ISA from day one, but a parent or guardian manages it as the "registered contact" until the child turns 16. From 16, the child can take over managing the account themselves — choosing what it's invested in, if it's a Stocks & Shares JISA. However, nobody can withdraw the money until the child turns 18, at which point the account automatically converts to an adult ISA and the money, and full control, become entirely theirs.
That last point matters: a JISA isn't a pot you can dip into for a new phone or a school trip. It's locked until adulthood — which is exactly what makes it useful for long-term growth rather than short-term saving.
Junior ISA vs an adult ISA vs a practice app
Parents often conflate these three, but they do genuinely different jobs:
| Account | Real money? | Who controls it | Best for |
|---|---|---|---|
| Junior Stocks & Shares ISA | Yes | Parent until 16, locked until 18 | Long-term, tax-free growth |
| Adult Stocks & Shares ISA | Yes | The young person, from 18 | Investing once they're an adult |
| Practice app (e.g. RIP.) | No — virtual only | The teenager, from 13 | Learning how markets move, with zero risk |
A JISA grows real wealth. A simulator teaches the behaviour — reading a chart, understanding why a price moved, sitting through a loss without it costing anything — that makes a teenager a more sensible investor once they're managing real money at 16 or 18. Neither replaces the other. Used together, a teen gets both the habit-forming practice and an actual pot of money growing quietly in the background. If you'd like the teenager-facing version of this, our guide on how to invest as a teenager in the UK covers it in their language, and ISAs, SIPPs and account types goes deeper on the wrappers themselves.
How much can go into a Junior ISA
For the 2026/27 tax year the Junior ISA allowance is £9,000, and the government has confirmed it stays frozen at £9,000 until April 2031 (you can always check the current figure on GOV.UK). Contributions can come from anyone and can be a lump sum or small regular amounts.
The allowance is a ceiling, not a target. Almost no family pays in £9,000 a year, and you don't need to. Even £20–£50 a month adds up meaningfully over a decade, because compound interest does the heavy lifting when there's a long runway ahead — and at your child's age, the runway is enormous.
How to open a Junior ISA
- Choose cash, stocks & shares, or both. If your teenager is more than about five years from turning 18, a Stocks & Shares JISA has more time to ride out market ups and downs.
- Pick a provider and compare fees. Some UK providers charge a flat annual fee, others a percentage of the pot. Fees compound against you exactly like returns compound for you, so smaller is usually better on modest balances.
- Open it as the registered contact. Only a parent or legal guardian can do this. You'll typically need the child's details and your own ID.
- Set up a contribution schedule. Regular monthly contributions build the habit and smooth out market timing better than one-off lump sums.
- Involve your teenager, and plan for 16 and 18. Show them the statements; explain why the value moved. At 16 they can start managing the investments with you; at 18 it becomes fully theirs. Have that conversation before the day arrives.
Common mistakes parents make
Waiting for a "big enough" lump sum before starting. Time in the market matters far more than the size of the first contribution. Starting small now beats starting big later.
Setting it and forgetting it. The tax-free growth is valuable, but the educational opportunity is wasted if your teenager never sees or understands what's happening inside the account.
Assuming a JISA teaches investing skill. It builds a pot of money — it doesn't, by itself, teach a teenager how markets behave, how to handle a loss, or how to think about a company before buying its shares. That's a separate, practice-based skill.
Confusing "locked until 18" with "no involvement until 18." Teenagers can and should be part of the conversation years earlier — that's where the lasting financial habits actually form.
Where practice fits in
Because a JISA is real money that's locked away, it's a poor place for a teenager to experiment or make mistakes. That's exactly the gap a virtual-money simulator fills. Apps like RIP. let teenagers pick real stocks, track real prices, and go head-to-head with friends — without a single real pound at risk. It won't replace the tax-free growth of a Junior ISA, but it does something a JISA can't: it turns the how and why of investing into something a teenager actually wants to get better at, before they're ever managing real money on their own. If your main question is whether an app like this is safe for your child, our is RIP. safe? page walks through the data handling, age gating and virtual-only design.
One important note: this guide is general information, not personal financial or tax advice, and RIP. is an educational simulation that is not authorised or regulated by the FCA. Junior ISA rules and allowances can change — confirm the current details on GOV.UK, and if you're unsure about your own situation, speak to an FCA-authorised adviser.
The practice, without the risk
Give your teenager a place to learn how markets work with virtual money and real prices — no real money, ever. Free on iOS, built for ages 13–18.
See RIP. on the App Store →Frequently asked questions
Who controls the money in a Junior ISA?
The child legally owns the Junior ISA from day one, but a parent or guardian manages it as the registered contact until the child turns 16. From 16 the child can manage the investments themselves. Nobody can withdraw the money until the child turns 18.
How much can you pay into a Junior ISA in 2026/27?
The Junior ISA allowance for the 2026 to 2027 tax year is £9,000, and it is frozen at £9,000 until April 2031. Anyone can contribute, but total contributions across both Junior ISA types cannot exceed the allowance in a tax year.
Can a parent take money out of a Junior ISA?
No. A Junior ISA is locked until the child turns 18 — neither the parent nor the child can withdraw the money before then, except in very limited circumstances such as terminal illness. That lock is what makes it a long-term account rather than everyday savings.
What happens to a Junior ISA when the child turns 18?
At 18 the Junior ISA automatically converts into an adult ISA. The money, and full control over it, become entirely the young person's, and everything paid in keeps its tax-free status.
Is a practice app the same as a Junior ISA?
No. A Junior ISA holds real money and grows real wealth; a practice app like RIP. uses virtual money on real market prices to teach the behaviour of investing with nothing at risk. They do different jobs and work well together — the JISA builds the pot, the app builds the skill.