Who can open a Junior ISA?

A Junior ISA can be opened by a parent or guardian for a child under 16, or by the young person themselves once they reach 16. The rule comes from the ISA regulations, which say an application "may be made by a person who is over 16" and who either has parental responsibility for the child or is the child¹. In practice, that means the person opening the account must be at least 16 and must stand in a legal parental role to the child.

The account is always held in the child's name, and the money in it belongs to the child. The Junior ISA allowance is £9,000 for the 2026-27 tax year, separate from the adult ISA allowance². Anyone can pay into the account once it exists, but only one person, the registered contact, controls it until the child is old enough to take over.

The most common confusion is about grandparents. They cannot open a Junior ISA for a grandchild unless they are the child's legal guardian, but they can pay into one a parent has opened³. The same applies to step-parents without parental responsibility, and to foster parents, who do not hold legal parental responsibility⁵.

Only a parent or guardian can open a Junior ISA for a child under 16

For a child under 16, the account must be opened by someone with parental responsibility. Providers state this consistently: "only parents or guardians with parental responsibility can open the account on behalf of the child"¹⁰, and "where the child is under 16 only a person with parental responsibility for the child can apply to open the Junior ISA"¹¹. A building society puts it plainly: "you can only open a Junior ISA if you have parental responsibilities of the child"¹⁰.

Parental responsibility is a legal status, not a matter of who cares for the child day to day. It normally sits with the child's mother, with the father if he was married to the mother at the time of birth or has acquired it since, and with anyone who has adopted the child or been granted it by a court. That is why a step-parent who has not formally acquired parental responsibility cannot open a Junior ISA, and why foster parents cannot either: "no, foster parents do not have legal parental responsibility"⁵.

The account is opened in the child's name, and the person opening it becomes the registered contact. That person deals with the provider, gives instructions and manages the investments or savings until the child is old enough to take over. The money is the child's from the moment it is paid in, even though they cannot touch it.

Where a child is looked after by a local authority, the rules make special provision. In relation to a Looked After Child, the Share Foundation must be treated as having parental responsibility for the purposes of the relevant regulations¹². That allows a Junior ISA to be opened for a child in care where the usual parental route is not available.

What parental responsibility means for opening an account

The legislation sets out two routes to making an application. A Junior ISA application may be made by a person who is over 16 and has parental responsibility for the eligible child, or by the eligible child themselves¹³. The same regulation names the eligible parties as "a person who has parental responsibility in relation to the eligible child who will hold the account; or the eligible child"¹.

That wording matters for two groups. First, it confirms that the person opening the account does not have to be the child's parent in the biological sense, only someone holding parental responsibility. Second, it confirms that a young person aged 16 or over can apply in their own right, without an adult.

Where parental responsibility changes hands, for example when a child is adopted or a carer is granted a formal order, the account management can be transferred. Official guidance covers "how to take over management of a Child Trust Fund or Junior ISA account, for people granted formal parental responsibility"¹⁴. The application to assume management requires the applicant to declare they are 16 or over and are either the named child or have parental responsibility for them¹².

Children aged 16 and 17 can open their own Junior ISA

From age 16, the young person can open a Junior ISA themselves. NS&I states that "for children aged under 16, only their parent or legal guardian can open an account. Children aged 16 or 17 can open the account themselves"¹⁵. A building society confirms that "children who are 16 or 17 years old may open and operate a Junior Cash ISA on their own behalf"¹⁶.

The ISA regulations make this work by treating the young person as an adult for the purpose of the management agreement: they "specifically permit any management agreement to have the effect as though the child was 18"⁵. That is why a 16 or 17 year old can sign up for a stocks and shares Junior ISA in their own name, even though the money stays locked until 18.

A 16 or 17 year old can also take over an account a parent opened earlier. Official guidance says "if your child is 16 or older they can become the registered contact for their Junior ISAs"⁶. NS&I describes the same step: "the young person can apply to manage their own account when they become 16"⁸. In some cases the provider asks for a signed form before online access is granted¹⁵.

At 16 the young person also gains other options. They can open an ordinary adult cash ISA alongside the Junior ISA, and manage their own Junior ISA at the same time⁷. The Junior ISA allowance remains separate from the adult allowance, so a 16 or 17 year old can use both in the same tax year¹⁷.

Residence rules: UK-resident children and Crown servant families

The child normally has to be living in the UK when the Junior ISA is opened. Guidance states that "usually, you can only open a junior ISA for a child living in the UK"¹⁸. The residence test applies to the child, not to the person opening the account, so a parent who lives abroad can still open a Junior ISA for a child who is UK resident: "the UK residency requirement only applies to the child at the point in time that the JISA is opened"⁵.

There is an exception for Crown servants. A child who is a UK Crown servant, a dependant of a UK Crown servant, or married to or in a civil partnership with a UK Crown servant may open a Junior ISA¹⁹. NS&I sets out the same rule for a young person opening their own account: they can do so if they are "resident in the UK, or a UK Crown servant, or married to or in a civil partnership with a UK Crown servant"⁸.

Anyone can pay in once the account is open

Opening the account and paying into it are two different things. Once a parent or guardian has opened a Junior ISA, anyone can contribute: "family and friends can help, anyone can pay money into the account including parents, grandparents, and other relatives"⁷. A wealth manager puts it the same way: "while these can only be opened by a parent or legal guardian, anyone can pay into the JISA"²⁰.

That means grandparents, aunts, uncles, family friends and the child themselves can all add money. The total paid in across all contributors must stay within the child's annual Junior ISA allowance, which is £9,000 for 2026-27². The allowance is separate from the adult ISA allowance, so a parent can pay into a Junior ISA and use their own ISA allowance in the same year.

One provider, Royal Bank of Scotland, states a narrower rule on its own Junior ISA: "currently, only the parent or guardian who opened the Junior ISA can make payments into the account"²¹. That is a product-specific restriction rather than a rule of the Junior ISA scheme, and it is worth checking the terms of any particular account before assuming third-party payments are accepted.

Who manages the account until the child turns 18

A parent or guardian manages the account while the child is under 16. Official guidance states that "a parent or guardian manages a Junior ISA for a child while they're under 16. Once the child reaches 16, they can choose to manage their own account"⁹. The person managing it is known as the registered contact, and they deal with the provider on the child's behalf²².

From 16, the young person can apply to take over. NS&I says "a parent or guardian can manage this ISA for a child while they're under 16. Once the child reaches 16, they can manage" it themselves, in some cases after registering with a signed form¹⁵. A building society describes the same handover: "parents or guardians can open and manage the account for children under 16, and from age 16 the child can apply to manage the account themselves"²³.

The money stays locked until the child turns 18. "Though the money in the Junior ISA legally belongs to your child, it's locked until their 18th birthday. At this point" the account becomes an adult ISA²⁴. Another provider confirms that "once your child reaches 18, the account will automatically become an adult ISA and they will be able to access the money in it"²².

The legislation supports the 16-year-old's right to give instructions. A child who has attained 16 and has assumed responsibility for management of the account may give instructions to the account manager as the registered contact²⁵. The same rule appears in the 2011 regulations: the named child may give instructions if aged 16 or over and has assumed responsibility for management¹².

Where the rules leave gaps

A few situations sit outside the straightforward parent-and-child case. Foster parents cannot open a Junior ISA because they do not hold legal parental responsibility⁵. Step-parents can only open one if they have acquired parental responsibility, for example through a formal agreement or a court order. Grandparents cannot open one unless they are the child's legal guardian³.

For children in care, the Share Foundation is treated as having parental responsibility for the purposes of the regulations, which allows an account to be opened where the usual parental route is not available¹². Official guidance also covers how to take over management of a Junior ISA for people granted formal parental responsibility, such as adoptive parents or carers with a residence order¹⁴.

If a child already has a Child Trust Fund, that does not prevent a Junior ISA being opened, but the two are separate accounts with separate rules. A Child Trust Fund can be transferred into a Junior ISA, and the same parental responsibility rules apply to who can manage it.

Where a reader needs free, impartial help understanding their options, MoneyHelper and the Money and Pensions Service provide guidance, and the Financial Ombudsman Service can look at complaints about an ISA provider. The Junior ISAs explained page covers how the accounts work once open, and Who can open an ISA covers the adult rules.