Best Cash ISA Rates March 2026: Where to Get Over 4% Tax-Free

Cash ISA rates in early 2026 remain competitive following the Bank of England's rate cycle. Easy-access Cash ISAs from challenger banks and specialist savings platforms are offering 4%+ AER on tax-free deposits. With the April 5 tax year end approaching, now is an ideal time to review whether you're getting the best rate on your existing ISA — or whether to open a new one before the deadline.

Easy-access ISAs allow withdrawals at any time without penalty, typically offering slightly lower rates. Fixed-rate ISAs lock your money for 1, 2, or 3 years in exchange for a higher guaranteed rate. If you're contributing ahead of April 5 and won't need the money in the near term, a 1-year fix often provides 0.3–0.5% more than the equivalent easy-access product — meaningful on a £10,000+ deposit.

Chip, Trading 212, and Moneybox all operate Cash ISA products with rates updated regularly. Paragon Bank and Aldermore typically offer competitive fixed-rate ISAs. Always check the current rate directly with the provider — rates move frequently and any figure cited in an article may be outdated within weeks.

You can transfer an existing ISA to a new provider without losing the tax-free status. Crucially, an ISA transfer does not count as a new subscription — your annual allowance is unaffected. If you have an old ISA earning 1.5% and a new provider is offering 4.2%, initiating a transfer before April 5 means your existing balance immediately starts earning the higher rate. The transfer process typically takes 15–30 working days.

At 4.2% on £20,000, year one interest is £840 — and that £840 is tax-free. In a standard savings account at the same rate, a higher-rate taxpayer pays 40% tax on that interest, keeping only £504. The difference is £336/year, compounding year over year. Over 20 years of maxing your ISA, the compounding tax advantage is significant — tens of thousands of pounds that stay with you rather than HMRC.