ISA Allowances and Rules for 2026/2027: A Simple Guide

ISAs are one of the most useful ways to save and invest in the UK.

The main reason is simple: money held inside an ISA can grow free of UK income tax and capital gains tax. HMRC's current guidance continues to show an overall adult ISA subscription limit of £20,000 a year.

That sounds straightforward, but ISA rules can still confuse people.

This guide explains:

• how much you can put into an ISA in 2026/2027
• the different types of ISA
• the rules for Junior ISAs
• how the allowance works
• some common mistakes to avoid

What is the ISA allowance for 2026/2027?

For adults, the overall ISA allowance is £20,000 in the current tax year. That is the maximum you can put into your ISAs across the year from 6 April to 5 April. HMRC's ISA manager guidance still shows the overall subscription limit as £20,000.

This does not mean £20,000 per ISA. It means £20,000 in total across all your adult ISAs for the tax year.

So, for example, you could:

• put all £20,000 into a Stocks and Shares ISA
• put £10,000 into a Cash ISA and £10,000 into a Stocks and Shares ISA
• put £4,000 into a Lifetime ISA and the other £16,000 into other adult ISAs

What types of ISA are there?

There are several types of ISA available in the UK.

Cash ISA

A Cash ISA works like a savings account, but the interest is tax-free.

Stocks and Shares ISA

A Stocks and Shares ISA lets you invest in assets such as shares, funds, bonds and ETFs, with tax advantages on growth and income inside the wrapper.

Lifetime ISA

A Lifetime ISA, often called a LISA, can be used for a first home or later life. The annual LISA limit is £4,000, and that amount counts towards your overall £20,000 ISA allowance.

Innovative Finance ISA

This is a more specialist ISA type linked to peer-to-peer lending and similar investments. Not all investors will use this type.

Junior ISA

A Junior ISA is for children under 18. It has its own separate allowance and separate rules. GOV.UK shows the current Junior ISA subscription limit as £9,000.

Can you split your allowance between different ISAs?

Yes. You can divide your £20,000 adult ISA allowance across different adult ISA types, as long as you do not go over the total limit. HMRC's subscription guidance confirms that the overall allowance can be spread across ISA types, with the Lifetime ISA limit sitting inside the overall cap rather than on top of it.

For example, you might choose:

• £5,000 in a Cash ISA
• £11,000 in a Stocks and Shares ISA
• £4,000 in a Lifetime ISA

That would use your full allowance.

Can you have more than one ISA?

Yes, in many cases. HMRC's updated rules allow adults to subscribe to more than one ISA of the same type in the same tax year, provided they stay within the overall annual limit.

That means you may be able to pay into:

• more than one Cash ISA
• more than one Stocks and Shares ISA

But this depends on what providers allow and how their own systems work. The key point is that the total across your adult ISAs must still stay within the £20,000 annual limit.

What is the Junior ISA allowance for 2026/2027?

The Junior ISA allowance shown in current GOV.UK guidance is £9,000 for the tax year. Anyone can contribute, but the total paid in for the child cannot go over that amount.

A child can have:

• one cash Junior ISA
• one stocks and shares Junior ISA

But unlike adult ISAs, a child cannot keep opening multiple Junior ISAs of the same type. HMRC's Junior ISA guidance makes clear that a child can only hold up to one of each type during childhood.

The money belongs to the child, and it cannot normally be withdrawn until they turn 18. The child can usually take control of the account at 16, but the money remains locked until adulthood.

Does a Junior ISA use up the parent's allowance?

No. A Junior ISA is completely separate from an adult ISA. So if a parent uses their full £20,000 ISA allowance, they can still pay into their child's Junior ISA as well, provided the child's own JISA limit is not exceeded.

What happens if you go over the ISA allowance?

If you pay in too much, the excess amount does not qualify for the tax-free benefits in the normal way. HMRC guidance indicates that excess subscriptions may need to be corrected, and providers may need to deal with the problem.

So it is worth keeping track of:

• what you have paid in
• which provider received it
• whether part of your allowance has already gone into another ISA

Can you transfer an ISA without affecting your allowance?

Yes. You can usually transfer an ISA to another provider without it counting again towards your allowance, as long as you use the proper transfer process. HMRC's ISA framework treats transfers differently from new subscriptions.

That means:

• you keep the tax wrapper
• you do not use up new allowance just by transferring
• you should not withdraw the money yourself and then try to re-add it unless you fully understand the rules

The same broad principle applies to Junior ISA transfers too.

What is a flexible ISA?

Some adult ISAs are flexible, but not all. A flexible ISA may let you withdraw money and replace it within the same tax year without using up extra allowance, but this depends on the product and provider. HMRC includes flexible ISA rules in its manager guidance and makes clear that flexibility is a specific feature rather than a universal rule.

So never assume your ISA is flexible unless the provider says so.

Simple examples

Example 1

You put £8,000 into a Cash ISA and £12,000 into a Stocks and Shares ISA. That uses your full £20,000 allowance.

Example 2

You put £4,000 into a Lifetime ISA, £6,000 into a Cash ISA, and £10,000 into a Stocks and Shares ISA. That also uses your full allowance, because the LISA sits inside the overall £20,000 cap.

Example 3

Your child has £3,000 paid into a cash Junior ISA and £6,000 paid into a stocks and shares Junior ISA. That uses the child's full £9,000 Junior ISA allowance.

Common mistakes to avoid

Forgetting the £20,000 is a total, not per account

The limit covers all your adult ISA subscriptions together.

Thinking a Lifetime ISA sits on top of the £20,000

It does not. The £4,000 LISA limit forms part of the overall adult ISA limit.

Assuming all ISAs are flexible

Some are, some are not. Always check your provider's terms.

Confusing adult ISA and Junior ISA limits

The adult ISA allowance and Junior ISA allowance are separate.

Final thoughts

The ISA rules for 2026/2027 are not as complicated as they first appear once you break them down.

The main points are:

• adults have an overall ISA allowance of £20,000
• Lifetime ISAs have a £4,000 limit within that allowance
• Junior ISAs have a separate £9,000 allowance
• adults can now subscribe to multiple ISAs of the same type, but the total limit still applies
• Junior ISA rules are stricter, with only one of each type allowed for the child

Used properly, ISAs remain one of the most useful tax-efficient tools available for UK savers and investors.

FAQ

What is the ISA allowance for 2026/2027?

The current overall adult ISA allowance is £20,000.

What is the Junior ISA allowance?

The current Junior ISA limit is £9,000 for the tax year.

Can I have more than one ISA?

Yes. Adults can subscribe to multiple ISAs of the same type, provided the overall annual limit is not exceeded.

Does a Lifetime ISA give me an extra £4,000 on top?

No. The LISA limit counts within the overall adult ISA allowance.

Can a child have both a cash JISA and a stocks and shares JISA?

Yes. A child can hold one of each type, but not multiple JISAs of the same type.

Does transferring an ISA use my allowance again?

No, not if you use the proper transfer process. Transfers are treated differently from new subscriptions.