Best cash Isas 2024

Cash Isa rates have been booming over the last couple of years thanks to 14 consecutive increases in the Bank of England base rate between December 2021 and August 2023. 

And while rates are no longer quite as high as they were a few months ago, a whopping 94% of cash Isas were paying more than the June rate of inflation (2%) when we checked on 29 July - so consider transferring your savings to a new Isa if your account isn't working hard enough.

Here, we reveal the cash Isas paying the highest interest across instant-access and fixed-rate deals as well as the best cash Isa providers, so you can decide on the right place to keep your money.

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The best cash Isa rates in August 2024

Our experts regularly scour the market for the best rates so you don't have to. Here's what you can currently get, based on how long you're willing to lock your cash up for. 

The top-rate instant-access accounts are based on an investment of £1,000, while for fixed-rate accounts it's £5,000.

The information in this article is for information purposes only and does not constitute advice. Please refer to the terms and conditions of the savings account provider before committing to any financial products. Please note that minimum and maximum deposit amounts vary, even across products with the same rate, so check the full details before you opt for a new account.

Best instant-access cash Isa rates 

Best 1-year fixed-rate cash Isa rates 

Best 2-year fixed-rate cash Isa rates 

Best 3-year fixed-rate cash Isa rates 

Best 4-year fixed-rate cash Isa rates 

Best 5-year fixed-rate cash Isa rates 

Which are the best cash Isa and savings account providers?

We know that customer service is an important factor for many people when choosing an Isa. But how do you find a bank or building society that combines great rates with top-notch customer service?

Which? is here to help. We've asked thousands of savers to rate their bank or building society, enabling us to create unique provider scores for all the major providers.

We've also analysed thousands of savings products and given each provider an overall product score, highlighting which companies offer consistently competitive rates. The full results from our most recent analysis (which covers both Isas and savings accounts) are as follows:

Which? Recommended Providers for Isas

Each year, we name the best savings providers as Which? Recommended Providers (WRPs). To win this award, the bank or building society must:

• achieve a provider score of 75% or above
• achieve an above-average product score of 58% or more
• be fully covered by the UK Financial Services Compensation Scheme (FSCS)
• offer products which are available nationally and are not tied to the purchase of another product with the same provider.

This year, our WRPs (in provider score order, rates correct as of 7 August 2024) are:

Marcus by Goldman Sachs

Marcus by Goldman Sachs received an 85% provider score. Savers gave it top marks for its application process and communication, as well as transparency of fees and charges. It was also praised for the interest offered on its instant-access account.

Marcus currently offers an instant-access savings account and cash Isa that both pay a competitive variable rate of 4.3% AER (4.22% gross), including a 0.49% (gross) bonus rate. This means the rate will fall to 3.79% AER (3.72% gross) after the first 12 months.

Paragon Bank

Paragon Bank achieved a provider score of 82%. It was highly rated by savers for its application process, communication and transparency of charges and penalties. Customers also gave it top marks for the quality of its instant-access rates.

Paragon Bank offers 2% AER on both its restriction-free instant-access cash Isa and savings account, but you can generally get higher rates if you choose a product that limits the amount of withdrawals allowed.

Coventry Building Society

Coventry Building Society earned a provider score of 79%. Savers gave it high ratings for its customer service, application process, regular communications, and transparency of charges and penalties. Its telephone banking service proved particularly popular. Its instant-access savings rates were also rated highly.

It is the only WRP for savings with a branch network. Like many providers, it pays more if you manage your account online and make fewer withdrawals.

Coventry Building Society offers a range of savings products with market-leading rates. Both its restriction-free instant-access cash Isa and savings account offer 3.4% AER.

Zopa

Zopa achieved a provider score of 78%, with customers giving it high ratings for its application process, regular communications, and transparency of charges and penalties. Its competitive instant-access rates were also commended.

Its Smart Isa offers a rate of 5.08% AER with instant access, while its Smart Saver (not an Isa) pays 4.54% AER.

Can any cash Isas beat inflation?

Inflation remained at 2% in June 2024 according to the Office for National Statistics (ONS).

When we checked on 29 July 2024, we found an impressive 540 cash Isas (94% of the market) offering an above-inflation interest rate.

You might also want to consider investing in a stocks and shares Isa, which could - though isn't guaranteed to - earn you more interest than a cash Isa.

How to transfer your Isa

If you're transferring your money from one Isa to another, there's only one way to do it: fill in a transfer form with your new Isa provider.

Many providers allow you to do this online. Once you've sent off the form, your new provider will get in touch with your old provider to make the arrangements.

The transfer process should be completed within 15 working days.

Once you've switched Isas, don't rest on your laurels. If the new account has an introductory bonus, make a note of when it ends, as you may want to switch again at that point to make sure you're still getting a good deal. 

If it's a variable-rate account, keep an eye on your rate to make sure it stays competitive.

• Find out more: cash Isa rules and allowances