Best Cash ISA Rates UK 2026

A Cash ISA is a tax-free savings account. Interest earned inside the wrapper is never taxed, regardless of how big the balance grows. You can pay in up to £20,000 per tax year (the overall ISA allowance, shared with Stocks and Shares ISAs, Lifetime ISAs, and Innovative Finance ISAs).

The wrapper has existed in its current form since 1999 and is the most-used tax shelter in UK personal finance. Around 12 million UK adults hold one. For anyone with a meaningful emergency fund or who is saving toward a near-term goal, a Cash ISA almost always beats an ordinary savings account once you cross the Personal Savings Allowance, which is £1,000 of interest a year for basic-rate taxpayers and £500 for higher-rate. Additional-rate taxpayers get no PSA at all, which is why high earners almost always max their Cash ISA first.

If you only ever hold a small balance and pay basic rate tax, the Personal Savings Allowance (PSA) covers you for the first £1,000 of interest a year. At a 4.5% rate that's about £22,000 of balance before you'd pay any tax at all. Below that level, a high-street savings account paying a slightly better rate can beat a Cash ISA.

The arithmetic flips quickly above the PSA. Every pound of interest above £1,000 is taxed at your marginal income rate - 20%, 40%, or 45%. A higher-rate taxpayer earning £2,000 of interest pays £600 in tax on the chunk above their £500 PSA. The same £2,000 of interest inside a Cash ISA is tax-free.

The other case where the Cash ISA wins is the long-run structural one. Move banks every year chasing the best rate and HMRC sees the interest reported on each account. Tax tracking gets fiddly. A Cash ISA shields you from that whole headache. Once a balance is inside the wrapper it stays tax-free even if it grows for 30 years.

Three structural formats, each with different trade-offs:

• Easy access - withdraw whenever, rate is variable, often the best home for an emergency fund. Trading 212, Chip and Atom Bank cluster at the top of the easy-access table.
• Fixed-rate (1, 2, 3 or 5-year) - higher rate in exchange for locking the money in. Most providers will allow early access with an interest penalty (typically 90 to 365 days of interest forfeited) but it is mechanically painful. Right for money you genuinely won't need until the term ends.
• Notice - intermediate option, e.g. 30, 60 or 90-day notice. Slightly higher than easy access, slightly lower than fixed. Less common since fixed-rate ISAs improved.

Most savers benefit from layering: easy access for the emergency fund, fixed-rate for any savings goal with a known horizon (e.g. tax bill due in 18 months, house deposit in 3 years).

A 'flexible' Cash ISA lets you withdraw money and replace it within the same tax year without using more of your annual £20,000 allowance. Standard (non-flexible) ISAs treat any withdrawal as permanent - if you put £10,000 in then withdraw £3,000, you've still used £10,000 of your allowance and can only contribute another £10,000 that year.

With a flexible ISA, the same withdrawal frees up £3,000 of headroom that you can replace before April. For an emergency fund parked in an ISA this is the difference between 'usable savings' and 'savings I'll only touch as a last resort'. Trading 212, Chip and Tembo all currently offer flexible Cash ISAs. Atom Bank and the building-society fixed-rate accounts typically do not.

If the wrapper is going to hold money that might genuinely need to come out and go back in (e.g. tax-bill cash sitting between January self-assessment and April), insist on flexibility. The rate difference vs a non-flexible alternative is usually irrelevant compared to the allowance you'd otherwise burn.

Cash held in a UK Cash ISA is protected by the Financial Services Compensation Scheme up to £120,000 per banking authorisation, per person (raised from £85,000 on 1 December 2025). If your provider goes bust, FSCS will refund up to £120k within seven working days for most claim types.

The nuance: some app-based ISA providers (Trading 212, Chip) are not banks themselves. They are platforms that place customer deposits with one or more partner banks. The FSCS limit applies at the partner-bank level, not the platform level. If your platform spreads £300,000 across three partner banks, all of it is covered. If two partner banks happen to be the same banking authorisation (e.g. NatWest and Royal Bank of Scotland share one), you're only covered for £120k against the pair. Always check which banks your platform uses and the FSCS coverage statement on their site.

Direct-FSCS providers (Atom Bank, the building societies, Nationwide) are simpler: one provider, one £120k limit, no cross-bank arithmetic. Worth considering if you hold balances near or above the FSCS threshold.

First, the myth-bust: there is no special over-60s Cash ISA rate. The best Cash ISA rates for over-60s are the same 4.5-5% easy-access and 4.5-4.85% fixed rates listed in the table above - the providers do not pay you more (or less) for being retired. A handful of high-street banks market an 'Over 60s ISA' (HSBC, for example), but in our view these age-branded accounts tend to pay less than the challenger-bank best-buys rather than more - check the live rate before assuming the over-60s label is doing you a favour. Martin Lewis has long made the broader point that your existing bank's loyalty rate is usually the one to avoid. Age is not a rate band.

What genuinely changes after 60 is which features matter:

• Access beats a fractionally higher fixed rate. If there is any chance you'll need cash at short notice for care costs, home adaptations or helping family, an easy-access ISA is worth more than the extra 0.2% on a 3-year fix you can't break without penalty. Layer a smaller fixed-rate pot underneath an easy-access buffer rather than locking the lot.
• Retirement savings are often the biggest cash balances people ever hold, so FSCS cover matters more. The limit is £120,000 per banking authorisation (raised from £85,000 on 1 December 2025), which means a £250,000 pot needs splitting across separate banking groups - and watch for shared licences (NatWest and RBS count as one).
• The wrapper also does more tax work in retirement than people expect. Pension drawdown and the State Pension are taxable income, and savings interest stacks on top, so many retirees find their £1,000 (basic-rate) or £500 (higher-rate) Personal Savings Allowance is already eaten by non-ISA interest. Every pound inside the Cash ISA then escapes tax that ordinary savings would not.

The practical answer: pick from the same best-buy table everyone else uses, weight easy-access more heavily than someone in their 30s would, and split large balances for FSCS cover. Skip the 'Over 60s' branded accounts unless their rate happens to match the market, which it rarely does.

The wrong frame for this comparison is 'which one wins on returns'. The right frame is 'which one wins for the money you are putting into it'.

• Cash ISA - for money you might need within the next 5 years, including your emergency fund and any near-term savings goals. The trade-off is that cash interest tends to lose to inflation over long horizons.
• Stocks and Shares ISA - for money you won't need for at least 5 years and ideally 10+. Historic real returns of global equities are around 5% a year; cash interest barely matches inflation. The trade-off is that equities can drop 30% or more in a single year, so don't use one if the money has to be there on a specific date.

Most UK savers benefit from holding both. Build the emergency fund first in a Cash ISA. Once that's covered (3 to 6 months of essential expenses), redirect new contributions into a Stocks and Shares ISA where the long-run real return is meaningfully higher.

The combined £20,000 annual allowance is shared. From April 2024 you can fund multiple ISAs of the same type in one tax year, so you can run a Trading 212 Cash ISA alongside a Vanguard Stocks and Shares ISA simultaneously without restriction.