Best Cash ISA Rates UK 2026: Earn Up to 4.71% Tax-Free

With savings rates still running well above their long-term average, a Cash ISA remains one of the most straightforward ways for UK savers to protect their interest from tax. Whether you want instant access to your money or are happy to lock it away for one, two or three years, there are competitive deals available right now — some paying over 4.5% AER.

In this guide, the SmartMoneyHQ team has compared the top Cash ISA rates available in May 2026, covering both easy access and fixed rate accounts. We explain what to look out for, how to choose the right deal for your situation, and answer the most frequently asked questions about Cash ISAs.

Best Cash ISA Rates at a Glance

The table below shows our top five picks across easy access and fixed rate Cash ISAs for May 2026.

Provider	Account Type	Rate (AER)	Min. Deposit	Key Features
Trading 212	Easy Access	4.51%* (promo rate)	£1	12-month bonus included (0.91% AER); apply via Moneyfactscompare by 2 June 2026; FSCS protected
Chip	Easy Access	4.32%* (incl. bonus)	£1	0.57% AER bonus for 12 months; new customers only; app-based; FSCS protected via ClearBank
Plum	Easy Access	4.32%* (incl. bonus)	£1	1.78% AER 12-month bonus; 4.00% for transfers; app-based; FSCS protected via Investec
UBL UK	1-Year Fixed	4.66%	£2,000	No access during term; competitive fixed rate; FSCS protected
Nationwide	3-Year Fixed	4.60%	£1	UK’s largest building society; 4.50% (1-yr), 4.55% (2-yr); FSCS protected; branch access

*Rate includes an introductory bonus that expires after 12 months. The underlying base rate will be lower — check provider websites before applying.

Our Top Cash ISA Picks: Detailed Reviews

1. Trading 212 Cash ISA — Best Easy Access Rate

Rate: 4.51% AER (includes a 0.91% AER 12-month bonus, available via Moneyfactscompare by 2 June 2026)
Minimum deposit: £1
Access: Instant

Trading 212 is best known as an investment app, but its Cash ISA has quickly become one of the most competitive easy access savings products on the market. The headline rate of 4.51% AER is currently the highest available on any easy access Cash ISA — though it does include a promotional bonus rate of 0.91% that applies for the first 12 months. To qualify for this rate, you must apply through Moneyfactscompare.co.uk before 2 June 2026.

The account is app-based and deposits are held with licensed banking partners, giving you FSCS protection up to £85,000. Withdrawals can be made at any time. Once the bonus period ends, the underlying rate becomes considerably lower, so you will want to shop around again at that point.

Good for: Savers who want the absolute highest easy access rate now and are happy to switch again in a year.
Not ideal for: Those who want long-term rate certainty without monitoring.

2. Chip Smart Cash ISA — Strong Rate, App Convenience

Rate: 4.32% AER (includes a 0.57% AER 12-month bonus)
Minimum deposit: £1
Access: Instant

Chip’s Smart Cash ISA offers 4.32% AER for new customers, which includes a 0.57% AER introductory bonus for the first 12 months. The underlying rate without the bonus sits at around 3.75% AER, which remains reasonably competitive — though not market-leading.

Chip operates entirely through its app and has built a strong reputation for its savings tools, including automated savings rules that help you set money aside without thinking about it. Customer deposits are held with ClearBank, which is FCA-regulated and FSCS protected. The account can accept ISA transfers from other providers.

Good for: Savers who want a slick digital experience alongside a strong headline rate.
Not ideal for: Those who prefer branch or telephone access.

3. Plum Cash ISA — High Bonus, Beware Transfer Rate

Rate: 4.32% AER for new money (includes a 1.78% AER 12-month bonus); 4.00% AER for ISA transfers
Minimum deposit: £1
Access: Instant

Plum’s Cash ISA matches Chip at 4.32% AER for new money — but be aware that the headline rate contains a very large introductory bonus of 1.78% AER. Once the 12 months expire, the base rate drops substantially, which means it is crucial to diarise a reminder to review the account before that happens. If you are transferring an existing ISA from another provider, the rate falls to 4.00% AER.

Plum is a well-regarded savings and investment app. Customer deposits are held with Investec, which carries full FSCS protection. As with Chip, the account is managed entirely via the app.

Good for: App-first savers depositing new money who want a strong rate today.
Not ideal for: Those transferring existing ISAs, or savers who are unlikely to review after 12 months.

4. UBL UK 1-Year Fixed Rate Cash ISA — Best One-Year Fix

Rate: 4.66% AER (fixed for 12 months)
Minimum deposit: £2,000
Access: None during the fixed term

United Bank UK (UBL UK) is a UK-authorised bank and FSCS-protected institution that has consistently offered some of the most competitive fixed rate ISAs on the market. Its 1-year fixed Cash ISA paying 4.66% AER is currently the best one-year rate available, and unlike the easy access deals above, there is no introductory bonus — this is a guaranteed rate for the full 12 months.

The catch is the higher minimum deposit of £2,000 and the fact that you cannot access your money during the term. Early closure may be possible in exceptional circumstances, but this is at the bank’s discretion and could result in an interest penalty.

Good for: Savers who have at least £2,000 and won’t need access to the money for a year.
Not ideal for: Those who might need emergency access to their savings.

5. Nationwide Fixed Rate Cash ISA — Best Building Society Option

Rates: 4.50% AER (1-year) | 4.55% AER (2-year) | 4.60% AER (3-year and 5-year)
Minimum deposit: £1
Access: None during the fixed term (early closure charges may apply)

Nationwide Building Society is the UK’s largest mutual lender and one of the most trusted names in savings. Its range of Fixed Rate Cash ISAs is market-competitive, with a 3-year deal paying 4.60% AER — matching the headline rates from challenger banks but with the security of a household name.

With a £1 minimum deposit, Nationwide’s ISAs are accessible to virtually every saver. You can also transfer in an existing ISA. Nationwide operates one of the UK’s largest branch networks, making it an excellent choice for those who value face-to-face service alongside competitive rates. All deposits are protected by the FSCS up to £85,000.

Good for: Savers who want a competitive fixed rate from a trusted high-street institution with branch access.
Not ideal for: Those seeking the very highest rate — specialist providers like UBL UK or Tandem tend to edge ahead on rate alone.

Easy Access vs Fixed Rate Cash ISAs: Which Is Right for You?

The choice between an easy access and a fixed rate Cash ISA comes down to your personal circumstances — specifically, how likely you are to need access to the money during the account term.

Easy access Cash ISAs let you withdraw your money whenever you need it. Most accounts allow unlimited withdrawals, though some impose a maximum number of withdrawals per year. The trade-off is that rates can change at any time, and in the current market many easy access rates are padded with short-term introductory bonuses.

Fixed rate Cash ISAs lock your money away for a set period — typically one, two, three or five years — in exchange for a guaranteed rate. They are ideal if you have a savings pot you are confident you will not need to touch. The best fixed rates currently exceed the best easy access rates, which is unusual; in many historical periods, the gap has been narrower.

A sensible strategy for many savers is to hold a core emergency fund in an easy access ISA while placing any longer-term savings into a fixed rate deal to capture the higher guaranteed rate.

Cash ISA Rules and Allowances for 2026/27

For the 2026/27 tax year, the annual ISA allowance remains £20,000. This is the maximum you can save across all types of ISA in a single tax year — Cash ISA, Stocks and Shares ISA, Innovative Finance ISA and Lifetime ISA combined.

• You can only open one Cash ISA per tax year, though you can transfer to a different provider at any point.
• Interest earned within a Cash ISA is completely free of income tax and capital gains tax, regardless of how much you earn.
• ISA allowances do not roll over from one tax year to the next — any unused allowance from 2025/26 cannot be carried forward.
• You can transfer existing ISAs without it counting towards your current year’s allowance.
• All ISA providers must be FCA-authorised, and deposits in UK-regulated banks and building societies are covered by the Financial Services Compensation Scheme (FSCS) up to £85,000 per person, per institution.

How We Chose the Best Cash ISAs

The SmartMoneyHQ team researches the savings market continuously, using data from comparison sites including MoneySavingExpert, Moneyfacts, and MoneyWeek, cross-checked against information published directly by providers. Our selection criteria prioritise the following factors:

• Headline rate: The AER (Annual Equivalent Rate) is the standard measure for comparing savings accounts — it reflects the compound interest you would earn over a full year.
• Underlying rate vs introductory bonus: We flag clearly when a headline rate includes a short-term introductory bonus, because the rate after the bonus expires will be significantly lower.
• Accessibility: We consider the minimum deposit, whether accounts accept ISA transfers, and any restrictions on withdrawals.
• Provider safety: All accounts recommended are held with FCA-regulated institutions and are covered by the FSCS.
• Ease of opening: We note whether accounts are app-based, online-only, or available via branch.

Frequently Asked Questions About Cash ISAs

What is a Cash ISA?

A Cash ISA (Individual Savings Account) is a type of UK savings account in which the interest you earn is sheltered from income tax. You can deposit up to £20,000 per tax year across all your ISAs. Unlike a standard savings account, any interest earned within a Cash ISA never counts towards your Personal Savings Allowance — it is entirely tax-free.

Is a Cash ISA worth it in 2026?

For many savers, yes — particularly higher and additional rate taxpayers who have already used up their Personal Savings Allowance (£500 for higher rate taxpayers, £0 for additional rate taxpayers). Even basic rate taxpayers with larger savings pots can benefit, as interest above £1,000 per year (in a non-ISA account) becomes taxable. With rates above 4% still available, the tax-free shelter of a Cash ISA is genuinely valuable.

Can I open more than one Cash ISA?

You can only open one new Cash ISA per tax year. However, you can hold multiple Cash ISAs from previous tax years simultaneously. You can also transfer ISAs between providers at any time without it affecting your current year’s allowance.

What happens to my Cash ISA if the bank fails?

Your savings are protected by the Financial Services Compensation Scheme (FSCS) up to £85,000 per person, per authorised institution. If a bank or building society regulated by the FCA fails, the FSCS will compensate you up to this limit. Note that if you hold multiple accounts with institutions that share a banking licence, the £85,000 limit applies to the total held across all accounts with that group, not per account.

Can I transfer my existing Cash ISA to a better rate?

Yes. You can transfer a Cash ISA to a new provider at any time, and doing so does not count towards your current year’s ISA allowance. Always ask your new provider to handle the transfer on your behalf — if you withdraw the money yourself and then redeposit it, it will use up your annual allowance. Check whether the new account accepts ISA transfers before applying, as not all accounts do.

What’s the difference between AER and gross rate?

AER (Annual Equivalent Rate) assumes interest is compounded and credited once per year. It is the standard comparison tool for savings accounts. The gross rate is the interest rate before compounding. For accounts that pay interest monthly, the gross rate will be slightly lower than the AER. When comparing accounts, always use the AER for a like-for-like comparison.

Do I need to declare Cash ISA interest on my tax return?

No. Interest earned inside a Cash ISA does not need to be declared on your Self Assessment tax return and is never subject to income tax, regardless of how much you earn or how high the rate is.

The Bottom Line

Cash ISAs remain an excellent home for your tax-free savings allowance in 2026, with rates well above their long-run averages. If you want the flexibility of instant access, Trading 212 (via Moneyfactscompare) currently leads the market at 4.51% AER — though be aware the bonus element means the rate will fall after 12 months. For those who can afford to lock money away, UBL UK at 4.66% (1-year) or Tandem Bank at 4.71% (2-year) offer the best guaranteed returns. Nationwide provides strong competition with the reassurance of a major high-street institution.

Whichever account you choose, make sure you set a calendar reminder to review the rate — especially if you pick an easy access account with an introductory bonus. Savers who shop around regularly will always get the best return on their money.

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Disclaimer: Rates correct as of 19 May 2026. Always check the provider’s website for the latest rates. SmartMoneyHQ is not a financial adviser. Nothing on this page constitutes personal financial advice. If you are unsure whether a product is right for you, please seek advice from an FCA-authorised financial adviser.