If you are a parent and are considering opening a Junior ISA in 2025, understanding the rules is essential. While the account itself is simple in concept, a tax-free way to save or invest for a child, the detail matters. Limits, eligibility criteria, and access rules all shape how the account works and when the money can be used.

This guide covers the key Junior ISA rules for the 2025/26 tax year, with clear answers to common questions and references to official sources where needed.

1. Junior ISA Limits for 2025/26

The annual Junior ISA allowance for the 2025/26 tax year is £9,000. This is the maximum that can be paid into a child’s Junior ISA across both types of account, Cash and Stocks & Shares, within a single tax year.

That £9,000 limit:

• Can be contributed by anyone (parents, grandparents, godparents, etc.)

• Can be paid as a lump sum or as monthly contributions

• Is use-it-or-lose-it; any unused allowance doesn’t roll over to the next tax year

The allowance resets every 6 April, in line with the new financial year. The simplest way to stay on track is by setting up a regular monthly payment, but many families also top up near the end of the tax year to use the full allowance.

It’s worth checking out any implications for ISAs post fiscal statements from them government as they review the tax free amounts regularly. For official confirmation of this year’s limit, see HRMC’s Junior ISA allowance page. 

2. Who’s Eligible for a Junior ISA?

Junior ISAs are available to children who meet the following criteria:

• Age: Must be under 18

• Residency: Must live in the UK

• Account status: Cannot hold both a Child Trust Fund (CTF) and a Junior ISA (unless the CTF is transferred)

The account must be opened by a parent or legal guardian, but anyone can contribute once it’s set up. That means extended family and friends can all chip in, whether monthly or for special occasions.

Children born between 2002 and 2011 may have a CTF by default. To open a Junior ISA, the CTF must first be transferred into a JISA, after which the CTF is closed.

3. Types of Junior ISA: Cash and Stocks & Shares

There are two types of Junior ISA:

• Cash Junior ISA – like a savings account, earns tax-free interest

• Stocks & Shares Junior ISA – invests in funds or equities, with potential for higher long-term returns but with risk attached

Each child can hold one of each type. The £9,000 limit applies across both accounts combined. Parents can choose one or both depending on their goals and risk appetite.

4. Can You Withdraw from a Junior ISA?

No, and this is an important consideration, withdrawals are not allowed before the child turns 18. The money belongs to the child from day one, but neither the parent nor the child can access it until their 18th birthday.

This rule applies to both Cash and Stocks & Shares Junior ISAs. The money is locked in, tax-free, until adulthood. The only exception is in rare, exceptional circumstances (such as terminal illness), and even then, approval from HMRC is required.

This is one of the most commonly misunderstood rules, and a source of frequent internet search interest, so it’s worth being crystal clear. Once it’s in until the child turns 18. 

5. What Happens at 18?

When the child turns 18, the Junior ISA automatically converts to a standard adult ISA. The money remains tax-free, and your child gains full legal control of the account.

They can:

• Withdraw some or all of the funds

• Keep the money invested in the ISA

• Transfer to another ISA provider

Many parents choose to use this milestone as a chance to teach financial literacy and help their child make wise decisions, whether that’s using the money for education, travel, or investing for the future.

6. Can a Child Have More Than One Junior ISA?

A child can only have one of each type at a time. They can’t have multiple Cash Junior ISAs or multiple Stocks & Shares Junior ISAs. However, you can transfer an existing account to a new provider if you find a better deal or want to consolidate. And, of course, if you have more than one child, the limits and allowances apply to each child and not the parent. 

7. Common Questions

Can we go over the limit?

Technically, no ISA providers will usually reject any payment that exceeds the £9,000 cap. But if it happens, HMRC may require the excess to be withdrawn and taxed.

What if we move abroad?

You can’t open a new Junior ISA while living abroad, but existing accounts can usually remain open, though new contributions may not be allowed depending on the provider.

What happens if the child dies before 18?

Funds in the Junior ISA will form part of their estate. It’s rare, but the rules around this are set out in HMRC guidance.

Know the Rules, Plan With Confidence

Junior ISAs are one of the most effective long-term savings tools for children in the UK—but they’re also tightly regulated. Understanding the rules around limits, eligibility, and withdrawals helps families plan with confidence and avoid surprises.

For further details, refer to HMRC or our very own Little Book of Savings. And if you’re ready to open an account or have questions about how to get started, our team here at the Children’s ISA is here to help.