Savings & ISAs

Best Cash ISA UK 2026/27

Top easy access and fixed rate Cash ISA rates — Trading 212 · Moneybox · Atom Bank · Zopa · NS&I compared

A Cash ISA lets you earn interest completely tax-free — no income tax, no matter how much interest you earn. With UK savings rates at 4–5% in 2026 and the Personal Savings Allowance only £500 for higher-rate taxpayers (£1,000 for basic-rate), a Cash ISA quickly becomes worthwhile for anyone with meaningful savings.

£20,000 annual ISA allowance: You can save up to £20,000 per tax year in ISAs. Unused allowance cannot be carried forward — use it or lose it. You can split the £20,000 across a Cash ISA and a Stocks & Shares ISA in the same year.

When does a Cash ISA beat a regular savings account?

Tax bandPSASavings at 4.5% AER to exceed PSAISA advantage from
Basic rate (20%)£1,000~£22,222Balance over ~£22k
Higher rate (40%)£500~£11,111Balance over ~£11k
Additional rate (45%)£0£0 — all interest taxableFrom £1
Rates change frequently. Cash ISA rates move with the Bank of England base rate and market competition. Verify current rates directly with each provider before opening. Rates shown in this guide reflect the market as of May 2026.

Best Cash ISA providers 2026/27

Trading 212 Best easy access rate
Type Easy access Cash ISA
Min deposit £1
ISA transfers Yes

Trading 212 has consistently offered one of the best easy access Cash ISA rates on the market, frequently topping best-buy tables. The account can be opened and managed entirely through the app, with instant access to your money and no withdrawal penalties. Eligible for ISA transfers from old providers.

Pros
  • Consistently top easy access rate
  • Instant access — no notice period
  • Open from £1 — no minimum balance
  • App-based — clean, simple interface
Cons
  • Rate can change — no guarantee of staying top
  • Newer provider — less established than traditional banks
  • App-only — no branch or phone option
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Moneybox Best for habit saving
Type Cash ISA (easy access + fixed)
Notice 32-day notice (easy access version)
ISA transfers Yes

Moneybox offers a Cash ISA with its popular round-up feature — linking to your bank card and rounding up every purchase into savings. Competitive rates alongside habit-forming savings tools make Moneybox ideal for people who struggle to save consistently. Also offers fixed-rate Cash ISA terms.

Pros
  • Round-up feature — saves automatically on every purchase
  • Competitive rates across easy access and fixed
  • Clear, simple app — good for new savers
  • Accepts ISA transfers
Cons
  • 32-day notice on easy access version — not instant
  • Rate may not always top the market
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Atom Bank Best fixed rate Cash ISA
Type Fixed rate Cash ISA (1yr, 2yr, 3yr)
Min deposit £50
ISA transfers Yes

Atom Bank consistently offers some of the best fixed rate Cash ISA deals on the market, particularly for 1-year and 2-year terms. Fixing your rate protects you if the Bank of England base rate falls. If you won't need the money for a defined period and want certainty, Atom's fixed Cash ISA is a strong choice.

Pros
  • Consistently competitive fixed rates — 1yr, 2yr, 3yr terms
  • Rate guaranteed for the fixed term
  • App-based — convenient management
  • FSCS-protected up to £85,000
Cons
  • Early withdrawal penalties apply
  • Cannot add to balance after opening (most fixed ISAs)
  • App-only — no phone or branch service
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Zopa Best all-round challenger bank ISA
Type Easy access and fixed Cash ISA
Min deposit £1
ISA transfers Yes

Zopa's full banking licence means it's FSCS-protected up to £85,000 and offers a range of Cash ISA products including easy access and fixed terms. Zopa is well-regarded for transparent pricing, no hidden fees, and a strong savings rate history. The app is clean and competitive rates make it a reliable choice.

Pros
  • Full UK bank — FSCS protection
  • Both easy access and fixed rate available
  • Consistently competitive rates
  • Good savings history and transparent terms
Cons
  • Rate may not always be market-leading
  • App-only management
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We may earn a commission if you open an account via our link — this doesn't affect our editorial independence.

NS&I Direct ISA Safest — government-backed
Type Easy access Cash ISA
Security HM Treasury — 100% secure
ISA transfers Yes

NS&I's Direct ISA is backed by HM Treasury — there is no FSCS limit; your entire balance is government-guaranteed. Rates are typically lower than market-leading fintech Cash ISAs, but the absolute security of government backing makes it attractive for savers with balances over the £85,000 FSCS limit, or those who prioritise safety above rate.

Pros
  • 100% government-guaranteed — no FSCS limit
  • Easy access — withdraw any time
  • Accepts ISA transfers
  • Trusted government institution
Cons
  • Rate usually below market-leading fintechs
  • Online management can feel dated
Open NS&I Direct ISA →

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Easy access vs fixed rate Cash ISA

FeatureEasy access Cash ISAFixed rate Cash ISA
RateVariable — changes with BoE base rateFixed for the term (1–5 years)
AccessInstant or short noticePenalties for early withdrawal
Best whenRates rising or may need moneyRates falling or certain you won't need it
FlexibilityAdd/withdraw freelyUsually deposit only at opening
Rate certaintyNo — rate can dropYes — guaranteed for term

Which Cash ISA is right for you?

Emergency fund or short-term savings

Trading 212 or Zopa easy access — instant withdrawal, top rate, no lock-in.

Know you won't need the money for 1–2 years

Atom Bank fixed rate — lock in today's rate before any potential BoE cuts.

Want savings automation and round-ups

Moneybox — round-up feature builds the habit; competitive rate on top.

Large balance (>£85k) or maximum safety

NS&I Direct ISA — only provider with 100% government guarantee, no FSCS cap.

Calculate your savings

Frequently asked questions

A Cash ISA is worth it if your savings interest exceeds your Personal Savings Allowance. Basic-rate taxpayers get a £1,000 PSA; higher-rate taxpayers only £500. With rates at 4–5%, you only need around £11k–£22k saved before interest becomes taxable. A Cash ISA shelters all interest tax-free. The allowance is use-it-or-lose-it — unused allowance cannot carry forward.

Yes. ISA transfers move existing ISA savings to a new provider without losing the tax-free status. Look for providers that accept ISA transfers. The receiving provider handles the transfer — never withdraw cash yourself, or you lose the ISA wrapper. Transfers can take 2–4 weeks for cash ISAs.

The overall ISA allowance is £20,000 per person per tax year. You can use all of this in a Cash ISA, all in a Stocks and Shares ISA, or split it across types — as long as the total doesn't exceed £20,000. You can hold a Cash ISA and a Stocks and Shares ISA with different providers in the same year.

If your interest exceeds your PSA, a Cash ISA is better — you pay no tax on the interest. For higher-rate taxpayers with over ~£11,000 saved at 4.5%, the Cash ISA saves tax immediately. For basic-rate taxpayers with modest savings under ~£22,000, the PSA often covers all interest and regular savings accounts can be competitive on rate.

Compare more ISA and savings options