Future Changes to Cash ISA Rules: What You Need to Know

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Savings

Future Changes to Cash ISA Rules: What You Need to Know

17 Dec 2025 Written by: Scottish Building Society

The government has announced future changes to Cash ISAs as part of the Autumn budget. These changes will not come into effect until the 2027/2028 tax year, but we want to ensure that you, our members feel fully informed ahead of that time.

What is changing?

From 6th April 2027, the start of the 2027/2028 tax year, the Government will introduce new rules for Cash ISA limits for savers under 65. These changes will not apply to those aged 65 or over, who will continue to receive the full Cash ISA allowance.

Is the ISA allowance changing?

The overall annual ISA allowance will remain £20,000. However, from April 2027, there will be changes to how much of that allowance some savers can pay in to Cash ISAs.

Under 65s

You will be able to save up to £12,000 per tax year into a Cash ISA.

Any remaining ISA allowance (up to the £20,000 annual limit) must be used in other types of ISA, such as a Stocks & Shares ISA, or a Lifetime ISA (subject to each ISA’s own rules and limits).

You can split your allowance across different ISA types in the same tax year, as long as:

No more than £12,000 goes into Cash ISAs, and

Your total ISA contributions do not exceed £20,000.

Age 65 and over

You will continue to be able to save up to the full £20,000 annual allowance into a Cash ISA, if you choose.

Why is the limit changing?

The change is designed to encourage more saving into investment products and support investment in UK companies.

When will the changes come into effect?

The new rules apply from 6th April 2027. Below is a simple timeline of what this means:

Tax year 2025/2026

Anyone over 18 can save up to £20,000 into a Cash ISA

Tax year 2026/2027

Anyone over 18 can save up to £20,000 into a Cash ISA

Tax year 2027/2028

ISA allowance remains £20,000

Under 65s: £12,000 Cash ISA cap, remaining £8,000 can be invested in other ISA types like a Stocks & Shares ISA

65 and over: Full £20,000 Cash ISA allowance remains available

Will this affect my existing ISAs?

No. Any money you’ve already saved in ISAs will not be affected by the changes coming in from April 2027.

The new rules only apply to new money you add to your ISAs from the 2027/28 tax year onwards.

We will keep you updated

As further guidance is published, we will continue to review the changes and keep members informed. If you have any questions, please contact us.

Future Changes to Cash ISA Rules: What You Need to Know

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