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Online ISA (Issue 4)

3.40%
Tax-free | PA / AER | Variable

An online individual savings account. The interest you earn  with an ISA is tax-free. It’s a great way to save and you can start with as little as £1!

Deposit Calculator

What could you get?

The estimated interest is for illustrative purposes only and assumes your savings are paid in on the 1st January and no further deposits or withdrawals are made. It doesn’t consider any individual circumstances. All interest rate information should be read in conjunction with the full product information and general terms and conditions for savings accounts. For products with a tiered interest rate – the calculation displayed is based solely on the highest interest rate available shown within the product. Please refer to the individual product terms and conditions for full details regarding tiered interest rates and withdrawals.

This account is for you if:

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You want to save your money and keep all the interest or returns tax‑free

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You don’t want to worry about paying tax on what you earn

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You want to make the most of your £20,000 annual ISA allowance and understand the importance of using it before the tax year ends

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You’re looking for a simple, tax‑free Cash ISA to help you save in a straightforward and secure way

Summary Box

Please note: this account is only available via Harpenden Online – it is not available to open by branch or by post.

Here’s more information about the product

Online ISA (Issue 4)

3.40% Tax-free PA/AER* variable.

Interest is calculated on a daily basis and added to your account annually on 5th April.

* The “Tax-free PA” is the annual rate of interest. Cash ISAs are not subject to the deduction of tax on savings income under current legislation. The annual equivalent rate (AER) is a notional rate which illustrates what the gross interest rate would be if the interest was paid and added to the account annually.

The information contained in this table forms part of the terms and conditions of the account and should be read in conjunction with our Cash ISA Terms and Conditions.

Interested in an Online ISA (Issue 4) Account?

You can open and manage your account using Harpenden Online.

Frequently Asked Questions

Here’s some helpful advice and guidance

A cash ISA allows you to avoid paying tax on a nominal amount of your savings. The amount you can save or invest in an ISA is referred to as the annual allowance. The allowance can change annually and is set by the Government.

You choose how you use your ISA allowance. You can split the amount you save into any combination of ISAs, Cash ISA, Stocks and Shares ISA, Innovative Finance ISA and Lifetime ISA, so long as the amount invested does not exceed the overall annual ISA allowance. Alternatively, you can save the full ISA allowance in a cash ISA.

Your annual allowance is for the whole tax year (6 April one year until 5 April in the following year), but you cannot invest more than the annual allowance in each tax year.

The manageress & staff of the Leighton Buzzard Branch were extremely helpful in walking me through the forms & actions I needed to enable me to change my Branch based savings & ISA accounts to the online versions.

Ian

February 2026

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Harpenden Building Society is my local building society, offers great products and excellent service to customers. I particularly like how they communicate with customers via email. Their messages are clear as they use simple language whilst being succinct. When I go into the branch, I always feel welcome and overall I have confidence in investing my money with HBS.

Sylvia Gomes

March 2026

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