How to open an ISA: age, ID and what you need

Who can open an ISA?

You must be 18 or over to open an ISA, and you must normally be resident in the UK. A Lifetime ISA has one more condition: you must also be under 40. That is what gov.uk says in its guide to ISAs.

• Cash ISA, Stocks and Shares ISA and Innovative Finance ISA: 18 or over.
• Lifetime ISA: 18 or over and under 40.
• Junior ISA: for a child under 18 who lives in the UK. A parent or guardian opens it, or a child aged 16 or 17 can open their own.

The ISA age limits guide has a table for every type. You cannot hold an ISA with someone else, so every ISA belongs to one person.

What is the minimum age for a Cash ISA?

It is 18. Since 6 April 2024 you must be 18 or over to open a Cash ISA, the same as for the other adult ISAs. Before that date, 16 and 17 year olds could open one.

A transitional rule let people who were 16 or 17 on 5 April 2024 carry on applying for, holding or transferring a single Cash ISA until they turned 18. HMRC’s guidance says those transitional arrangements ended at 11:59pm on 5 April 2026. A child under 18 can still have a Junior ISA, and children aged 16 and 17 can open their own.

Do you need to live in the UK?

Yes, with some exceptions. gov.uk says you must be resident in the UK. If you do not live in the UK, you can still open an ISA if you are a member of the armed forces or a Crown servant (for example in the diplomatic or overseas Civil Service), or their spouse or civil partner.

HMRC’s guidance says the UK here means England, Scotland, Wales and Northern Ireland, and does not include the Channel Islands or the Isle of Man. gov.uk has a guide to working out your residence status. HMRC says that if you are unsure whether you are UK resident you cannot apply for an ISA, and a provider must not open one provisionally.

What do you need to open an ISA?

Your provider will ask for the details HMRC requires on an ISA application:

• your full name
• your permanent residential address, including the postcode
• your date of birth
• your National Insurance number
• declarations that you are 18 or over, are UK resident (or meet one of the exceptions), will not pay in more than the overall limit in the tax year, and that the money you pay in belongs to you

National Insurance number. gov.uk says you will need it. If you do not know it, you can find it online, through your personal tax account, in the HMRC app, or on a document such as a payslip, P45 or P60. HMRC’s guidance says an application for a Cash ISA, Stocks and Shares ISA or Innovative Finance ISA can instead confirm that you have not been issued with a number but are still eligible. A Lifetime ISA application must include the number. From 6 April 2027, HMRC’s guidance says any ISA account receiving a subscription will need a National Insurance number or a declaration that you are not eligible for one.

Proof of identity. Money laundering rules require regulated firms to carry out customer due diligence, which means identifying customers and checking they are who they say they are. For you, that usually means photo ID such as a passport, plus your address and date of birth. Each provider decides which documents it accepts.

A first payment. HMRC says an ISA does not begin until a subscription is made. A provider can set conditions, such as a minimum lump sum, and you must pay in with your own money.

How do you apply for an ISA?

You apply to a provider. gov.uk says you can get an ISA from banks, building societies, credit unions, friendly societies, stockbrokers, peer-to-peer lending services, crowdfunding companies and other financial institutions. It says to contact your provider directly for how to open an ISA with them.

How you apply depends on the provider. Some offer an app or an online application, some take applications by phone, and some only in a branch or by post. HMRC’s guidance allows applications in writing, by email or by phone, and also covers applications made online.

The steps are usually:

1. Choose the type of ISA and a provider. HMRC says a provider needs a separate application for each type of ISA, so one form cannot cover a Cash ISA and a Stocks and Shares ISA together.
2. Give your details and confirm the declarations.
3. Make your first payment, which starts the ISA.
4. Check the terms, including any rules or charges for withdrawals.

If you change your mind soon after applying, most accounts give a cooling-off period in which you can cancel without using up your allowance: see can you cancel an ISA or an ISA transfer.

Rates change often, so this page quotes none. Our Cash ISA rate tables rank accounts by rate.

Can you open more than one ISA?

Yes. Since 6 April 2024 you can pay into more than one ISA of the same type in a tax year, as long as everything you pay in stays within your £20,000 allowance. gov.uk’s example is £10,000 in one Cash ISA, £3,000 in another Cash ISA and £7,000 in a Stocks and Shares ISA in one tax year.

There are exceptions. You can only pay into one Lifetime ISA in a tax year, and a child can have only one cash Junior ISA and one Stocks and Shares Junior ISA. The Cash ISA limit, £20,000, applies to all your Cash ISAs added together, so more accounts do not mean more room. See how many ISAs you can have.

Open a new ISA or transfer an old one?

If your money is already in an ISA, you can move it instead of starting again. gov.uk says you can transfer all or part of your ISA savings from one provider to another at any time. It can be to the same type of ISA or a different one, and the money can have been paid in this year or in earlier years.

Ask the new provider for its transfer form. If you withdraw the money yourself instead, gov.uk says you will not be able to reinvest that part of your tax-free allowance again. Providers can have their own restrictions and may charge. See how an ISA transfer works.

A planned block, from 6 April 2027, on savers 64 or under transferring a Stocks and Shares or Innovative Finance ISA into a Cash ISA is unconfirmed after the Budget. See ISA transfers.

Can you open an ISA for someone else?

Not an adult ISA, unless you are legally authorised to act for the person. gov.uk says you cannot hold an ISA with someone else, and HMRC’s guidance says an individual cannot apply for an ISA on behalf of someone else unless they are legally authorised to do so. gov.uk says you can apply for and manage an ISA for someone who lacks the mental capacity to do it themselves if you hold lasting power of attorney for them or you are their financial affairs deputy.

For a child, a parent or guardian with parental responsibility can open a Junior ISA, and the money belongs to the child. Only a parent or guardian can open one for a child under 16, and children aged 16 and 17 can open their own. Anyone can pay into a Junior ISA once it is open. See Junior ISAs.

Can you open an ISA at any time?

Yes. You can apply at any point in the tax year, which runs from 6 April to 5 April. HMRC’s guidance says an ISA can be opened when you agree to the provider’s terms and apply to subscribe, and that it begins once the first payment is made.

The allowance resets on 6 April, and HMRC says unused allowance cannot be carried forward to the next year. An application received near the end of the tax year counts as opened in that year if the provider accepts it and your first payment is made before the year ends. Some products close to new money on a set date, so check the dates in the terms. See the ISA deadline.