How to Give Your Child £40,000 by 18 (Junior ISA Plan)

If you invest £84 a month into a Junior Stocks & Shares ISA from the day your child is born, and achieve an average annual return of 8%, by the time they turn 18 you’ll have built a pot of around £40,000.

Of that, you’ll have personally contributed £18,144.

That extra £22,176 is pure compound growth – money generated not by saving harder, but simply by investing early and leaving it alone.

And inside a Junior Stocks & Shares ISA it’s completely tax free.

Junior Stocks & Shares ISA Growth Chart | Up The Gains

What £84 a month could grow to over 18 years

Based on £84/month invested from birth. Returns shown are illustrative only.

Stocks & Shares JISA (8% avg) £40,320

Cash JISA (3.5% AER) £27,180

Total contributed £18,144

Choosing a Stocks & Shares JISA over a Cash JISA could mean £13,140 more for your child at 18 — from the same £84 a month.

All figures are illustrative only. The 8% annual return is a historical average and is not guaranteed. Investment values can fall as well as rise. Past performance is not a reliable indicator of future results. Tax treatment depends on individual circumstances and may change. Capital at risk.

So what actually is a Junior Stocks & Shares ISA?

A Junior Stocks & Shares ISA is a tax-free investment account for children under 18. Any money you invest inside it grows completely free of tax – no income tax, no capital gains tax, nothing.

You can put in up to £9,000 per year. The money is locked until your child turns 18, when it automatically becomes theirs.

There are two types of Junior ISA – a cash JISA (like a savings account) and a stocks & shares JISA (invested in the market).

We’re talking about the stocks and shares version, because over 18 years, the stock market has historically beaten any cash savings rate.

Our Top Pick

Junior Stocks & Shares ISA - IG

IG launched their Junior ISA recently and it's already one of the best on the market. The reason is straightforward: they charge nothing.

No account fee, no commission on stocks or ETFs.*

With over 12,000 shares and ETFs available, there's plenty to choose from whether you want to go hands-on or keep things simple with a broad index tracker.

*foreign exchange charges apply if you invest in non-UK shares

Pros:

£0 account fee
£0 commission on stocks and ETFs*
12,000+ shares and ETFs
No minimum monthly contributions
3.75% AER on uninvested cash

Cons:

Visit IG

Capital at risk when you invest. T&Cs and ISA rules apply.

How to set one up in 5 steps

Step 1: Open a Junior Stocks & Shares ISA account

Any parent or guardian can open one for a child under 18. It takes about 10 minutes online. You’ll need your child’s details and your own ID.

Step 2: Choose an investment

Don’t overthink this. A simple global index fund gives your child exposure to thousands of companies worldwide and has historically performed better than many actively managed funds. Index funds are low cost and diversified, designed to set and forget for long term growth.

Step 3: Set up a monthly direct debit

Pick an amount you can genuinely afford every month. Even £25 is worth doing. Set up a direct debit so it happens automatically – no willpower required.

Step 4: Add lump sums when you can

Birthday money. Christmas gifts from grandparents. Any bonuses. Anything you can add early will have more time to compound.

Step 5: Leave it alone

Seriously. The worst thing you can do is panic when markets dip and pull the money out. Time in the market beats timing the market.

Our top pick: IG Junior Stocks & Shares ISA

There are plenty of providers out there. We’ve compared nine of the biggest. But one stands out above the rest right now.

IG has launched a Junior Stocks & Shares ISA with zero platform fees and zero trading fees. Plenty of providers still charge a yearly fee, in some cases up to around 0.7%. Over 18 years on a growing pot, that adds up to thousands of pounds.

With IG, the account and dealing are free. Just note a 0.70% FX fee applies when you buy US shares.

Our Top Pick

Junior Stocks & Shares ISA - IG

IG launched their Junior ISA recently and it's already one of the best on the market. The reason is straightforward: they charge nothing.

No account fee, no commission on stocks or ETFs.*

With over 12,000 shares and ETFs available, there's plenty to choose from whether you want to go hands-on or keep things simple with a broad index tracker.

*foreign exchange charges apply if you invest in non-UK shares

Pros:

£0 account fee
£0 commission on stocks and ETFs*
12,000+ shares and ETFs
No minimum monthly contributions
3.75% AER on uninvested cash

Cons:

Visit IG

Capital at risk when you invest. T&Cs and ISA rules apply.

The questions people always ask

I can't afford £84 a month. Is it still worth it?

100%. The example above uses £84 because it hits £40k. But £25 a month from birth is around £12,000 at 18, and £50 a month is £24,000. Start with whatever you can genuinely afford and increase it when you can.

My child is already 5. Have I missed the boat?

No. You still have 13 years of compound growth ahead of you. £100 a month started at age 5 is around £28,000 by their 18th. Not £40k, but still a life-changing amount.

What if the market crashes?

Over an 18-year period, market crashes can actually help if you are contributing monthly, because you buy more units when prices are low. Every major crash in history has eventually recovered. Don’t panic, don’t sell.

Can grandparents contribute too?

Yes. Anyone can contribute to a Junior Stocks & Shares ISA as long as the total stays within £9,000 in a tax year. Grandparents adding £50 a month or a birthday lump sum can make a big difference.

What happens if my child doesn't use it wisely at 18?

It’s a fair concern. From age 16 they can manage the account, and at 18 it is legally theirs. The best safeguard is talking to them about money as they grow up, so they understand what it is for.

Is the money locked away forever?

Until your child turns 18, yes, with one exception: terminal illness. That lock is the point. The money cannot be raided when the boiler breaks or Christmas gets expensive, so it stays invested and growing as intended.

Want to compare more providers?

We’ve reviewed IG, Hargreaves Lansdown, AJ Bell, Fidelity, Interactive Investor, Vanguard, Wealthify, Charles Stanley and Bestinvest – all in one place.

See our full Best Junior Stocks & Shares ISA guide for more.