Published: 19 May 2026
So, you’ve dipped your toes into the world of ISAs (Individual Savings Accounts) and now want to know what you’ll be getting from your hard-earned cash. Well, you’ve come to the right place! We’re about to tell you what cash ISA interest is all about, as well as answering some of your burning questions.
Do you pay tax on cash ISA interest?
One of the biggest perks of cash ISA interest is that it’s tax-free. Yep, you read that right!
Unlike some other savings that can see you waving goodbye to a chunk of interest in taxes, cash ISA interest stays in your pocket.
So, is cash ISA interest tax-free?
Absolutely! We’ll say it louder for the people at the back.
No matter what type of cash ISA you’re saving with, you get to keep all of the interest you make. Just make sure to stay within your ISA allowance – which is £20,000 for the 2026/2027 tax year.
What’s an ISA allowance we hear you ask? Check out our article on ISA allowances.
From 6 April 2027 there’s a change you need to know about. The ISA allowance remains at £20,000 but if you’re aged under 65, the amount you could save in a cash ISA each tax year will reduce to £12,000.
But savers aged 65 and over aren’t affected – they’ll still be able to save their full £20,000 allowance in a cash ISA.
Does interest count towards your ISA limit?
Here’s the good news: interest doesn’t eat into your ISA allowance. This limit is just for the money you put into your ISA, not the interest it generates. So you can max out your allowance and still enjoy all the interest that comes your way.
When is cash ISA interest paid?
It’s the moment we all eagerly await! It’s time to consider when you’ll finally get your hands on your cash ISA interest. It’s almost as exciting as waiting for your favourite TV show to drop a new season…
This will depend on the type of ISA you have, as well as the provider itself. Some pay interest monthly and many annually – so it is important to check the terms and conditions of your account.
How is ISA interest calculated?
This will depend upon the account you choose, usually for cash ISAs it’s calculated daily as a percentage of the balance saved and paid on an annual or monthly basis. It also depends on the interest rate and if its variable or fixed.
Simply put, the more money you have in your account, the more interest you’ll earn.
In a nutshell, ISA interest is like the icing on your financial cake – sweet, tax-free and a delightful addition to your savings. Just remember, tax rules and interest rates can change so keep a watch out for your provider’s updates.
Not got a cash ISA yet? Make sure to check out our ISA rates. Happy saving!
This article is not advice, and you should seek independent financial or legal advice if needed.
Tax-free means that interest payable is exempt from income tax.
The tax treatment depends on the individual circumstances of each customer and may change.
Cash ISAs are available to individuals aged 18 or over who are resident in the UK for tax purposes.
