
19 Nov 2025 · 3 min read

A Cash ISA is a savings account where the interest is tax-free. If you’re nudging your Personal Savings Allowance (or just want a clean, tax-simple pot), it’s one of the easiest wins in UK savings.
Allowance: You can save up to £20,000 in total across your ISAs in the 2026/27 tax year.
Multiple ISAs: Since April 2024 you can open and pay into more than one ISA of the same type in the same tax year (Cash, Stocks & Shares, Innovative Finance, Lifetime) — still within the overall £20,000 cap. (Lifetime ISA contributions are capped at £4,000 within that.)
Tax: Interest inside a Cash ISA is tax-free.
Access: Choose easy access (variable rate, withdraw whenever) or fixed-term (higher rate, but penalties if you break early).
Savers who want tax-free interest with minimal admin.
UK tax residents aged 18+ (under-18s should look at Junior ISAs).
Anyone nearing or exceeding their Personal Savings Allowance who wants to ring-fence interest from tax.
You can split your £20,000 allowance across different ISA types in any mix you like. Since the 2024 rule change, you can also pay into more than one Cash ISA in the same tax year — handy if a better rate appears mid-year. Just remember: the combined total paid into all ISAs cannot exceed £20,000 for 2025/26.
Want a better rate? Ask the new provider to do the transfer for you. If you withdraw to your bank and re-deposit yourself, you lose the tax-free wrapper.
You can transfer current-year and previous-years’ ISA money (in full or part, depending on provider rules).
Stocks & Shares ISA money can be transferred into a Cash ISA if the provider accepts it.
Some providers charge transfer/exit penalties — weigh these against the rate gain before moving.
Some Cash ISAs are flexible. With these, you can take money out and put it back in within the same tax year without reducing your remaining allowance. Not all providers offer flexibility; check the product details. (Flex doesn’t apply to Lifetime ISAs or Junior ISAs.)
Easy access ISAs let you withdraw anytime (rate is typically variable).
Fixed-term ISAs lock your money for a set period; early withdrawals usually come with interest penalties.
Watch for teaser rates that drop after a few months; mark your calendar to review and, if needed, transfer to a better deal.
Cash in UK-authorised banks/building societies — including within a Cash ISA — is covered by the Financial Services Compensation Scheme (FSCS) up to £120,000 per person, per authorised firm (£170,000 joint).
Note: multiple brands can share one banking licence (e.g., Lloyds/Halifax/BoS). If you’re over £85k across linked brands, consider spreading across different licences.
You can open Cash ISAs online, in-app, in branch, by post, or phone, depending on provider. Use comparison sites to find leading easy-access or fixed rates, and check for:
Bonus terms (and when they end)
Transfer-in acceptance and any fees
Flexible ISA capability
FSCS licence of the underlying bank (especially on marketplaces)
Start with the provider’s own complaints process. If not resolved, you can take it to the Financial Ombudsman Service.
A surviving husband, wife or civil partner can receive an additional permitted subscription (APS) equal to the value of the deceased’s ISAs — effectively keeping that amount within the ISA shelter. If there’s no surviving spouse/partner, ISA savings pass to the estate and lose the ISA wrapper, though interest can remain tax-free for a limited administration period.