Many parents reach the same point: they want to put money aside for their child, but want to make sure they are choosing the right savings route before committing. Junior ISAs are designed for long-term saving and are one of the most widely used products for children in the UK, but the rules can feel unintuitive at first. Most questions come down to the same themes: who can open the account, whether it should be cash or investments, how the allowance works, and what happens when the child turns 18. This guide clearly explains how to open a Junior ISA in the UK in 2026. 

Can you open an ISA for a child?

Yes. The UK product designed for this purpose is a Junior ISA.

A Junior ISA is a savings or investment account held in the child’s name, but opened by a parent or legal guardian. The child owns the money from the moment it goes in, but cannot access it until they turn 18. The account is designed to keep savings protected and tax-efficient, which is why it is popular with families saving for long-term goals.

The Children’s ISA offers Junior ISA products built specifically for this purpose,  long-term savings for children, rather than as a secondary add-on to adult banking services. 

What is a Junior ISA and how does it work?

A Junior ISA is a tax-efficient account for children under 18. It allows a child to build savings in a way that protects interest, dividends and investment gains from tax. The key trade-off is that the money is locked away until the child becomes an adult.

There are two types of Junior ISA:

Cash Junior ISA

A Cash Junior ISA works like a savings account. You deposit money, and the provider pays interest on the balance. Interest earned within the account is tax-free. Like all Junior ISAs, it remains locked until the child turns 18.

This type of Junior ISA tends to suit families who want the structure and tax efficiency of an ISA but prefer cash-based saving.

Stocks and Shares Junior ISA

A Stocks and Shares Junior ISA allows money to be invested. The value of investments can rise or fall, and returns are not guaranteed. Gains and income remain tax-free within the ISA wrapper, and the account is also locked until age 18.

Key Junior ISA rules (and the parts people get wrong)

The rules behind a Junior ISA are simple once they are stated clearly.

First, there is an annual Junior ISA allowance, which is the maximum amount that can be paid into a child’s Junior ISA across a tax year. The allowance is set by the government and can change.

Second, a child can usually hold one Cash Junior ISA and one Stocks and Shares Junior ISA at the same time, but contributions across both types still count toward the same annual allowance. For example, the Junior ISA allowance in 2026/27 is £9,000, so the contributions could be split across both. 

Third, the money belongs to the child, not the parent. That is why it cannot be withdrawn early.

Finally, at 18, the Junior ISA converts into an adult ISA, and the child gains full access and control.

Who can open a Junior ISA? And the Eligibility rules

A Junior ISA must be opened by:

• a parent, or
  
• a legal guardian
  

If you are not the child’s parent or legal guardian, you cannot open the account, even if you plan to contribute. However, you can usually add money once the account is open, depending on the provider and the payment methods they allow.

What you need to open a Junior ISA

Most Junior ISA providers will ask for the same basic information:

• the child’s details (name, date of birth, address)
  
• the parent or guardian’s details
  
• proof of identity (often completed digitally)
  
• bank details for payments, particularly if you want to set up monthly contributions
  

Opening a Junior ISA with The Children’s ISA is completed online, and the key is having the right information to hand so you can finish it in one session.

Step-by-step: how to open a Junior ISA in 2026

Step 1: Decide what you are saving for

This sounds simple, but it shapes everything that follows.

Parents usually open Junior ISAs for:

• a pot for adulthood
  
• future education costs or training
  
• a head start for life at 18, whether that’s a first car, university expenses, or a deposit contribution
  

If your savings goal is long-term and you do not need access to the money, a Junior ISA is designed for that job.

Step 2: Choose Cash or Stocks and Shares 

If you want a cash-based approach, a Cash Junior ISA provides a straightforward savings route. If you are considering investments, a Stocks and Shares Junior ISA exists for that purpose, but values can rise and fall.

If you are unsure, it is often easier to start with the product type you understand. The Children’s ISA only provides Investment ISAs. And, over the long term and based on historical data, investments tend to outperform cash over the long term. 

Step 3: Open the account

Most providers now allow online applications. The steps are typically:

• Enter child details
  
• Confirm your identity
  
• Choose the Junior ISA type
  
• Open the account and receive confirmation
  

At the Children’s ISA we try to make opening, switching and investing in a Junior ISA as easy as A, B, C. 

Step 4: Add an initial payment or set up monthly deposits

Once the account is open, you can usually:

• make a one-off deposit
  
• set up a monthly contribution
  
• or do both
  

There is no rule that says you must contribute monthly, but many families find it useful. It makes saving consistent and removes the mental admin of remembering to top up.

If you do set up regular payments, it is still worth reviewing them periodically, but do bear in mind, like all investments, the fund in a Junior ISA can go up as well as down. 

Step 5: Keep track of the Junior ISA allowance

The Junior ISA allowance applies to the total paid in for the child within that tax year, regardless of who contributes and regardless of whether the money is split between cash and investments.

A practical approach is:

• keep a simple record of contributions
  
• avoid exceeding the allowance
  
• coordinate contributions if other family members also pay in
  

What happens when your child turns 18?

At 18:

• The Junior ISA becomes an adult ISA in the child’s name
  
• The child gains full control
  
• The money becomes accessible
  

This matters because many parents assume they will retain control. They won’t. The child owns the money from the outset, and at 18, they can withdraw or leave it invested as they see fit.

Common problems and how to avoid them

“I’m not sure if I can open one.”

Only parents or legal guardians can open a Junior ISA. If you’re not one, you’ll normally need the parent or guardian to open it. Grandparents often want to play a part in investing for their grandchildren and can contribute, but they cannot open an account unless they are a legal guardian. 

“I opened one but can’t withdraw.”

Junior ISAs are locked until 18. That is the trade-off for a protected pot and tax-efficient savings structure.

“I don’t know whether to choose cash or investments.”

Decide based on your goal and time horizon. This is a very personal decision and is often dictated by appetite for risk. It is worth bearing in mind, however, that here at the Children’s ISA, we offer a carefully selected range of funds across defensive, balanced, adventurous, and shariah options, ensuring that we have a fund to suit your circumstances.

“I’m worried about what happens at 18.”

At 18, the child gains access and control. This is why many families prefer to discuss expectations early.

Why families choose The Children’s ISA

The Children’s ISA is not a bank, but, we are not a newcomer. We have been providing Junior ISA savings products since 2011, which means we have supported families through a decade and a half of rule changes, shifting savings habits and rising financial pressure.

A specialist provider tends to bring three advantages that matter in practice:

Clear explanations

Junior ISA rules are simple, but only if they are explained properly. The Children’s ISA is built around plain language and demonstrable results. 

Straightforward setup

Many families want an account that is simple to open, easy to contribute to and easy to understand. We focus on that.

Designed for children’s investments, not general banking

Some providers offer Junior ISAs as part of a wider portfolio. The Children’s ISA is focused on one job: helping families invest for children.

For many parents, the deciding factor is not a glossy promise. It is confidence that the account is correct, compliant, and easy to maintain for the long haul.

FAQs

How do I open an ISA for my child?

You open a Junior ISA through a provider such as The Children’s ISA. You must be a parent or legal guardian, and you’ll need the child’s details and your own identification.

Can I open a Junior ISA online?

Yes. Most providers, including The Children’s ISA, allow online applications.

Can you have both a Cash and Stocks and Shares Junior ISA?

In many cases, yes. The rules generally allow one of each type per child, but contributions across both still count toward the annual Junior ISA allowance.