Premium Bonds and cash ISAs are both popular UK savings options, but they work very differently. Premium Bonds pay no interest - instead the holder enters a monthly prize draw where returns depend on luck. A cash ISA pays a fixed or variable interest rate, tax-free. Choosing between them depends on the saver's tax position, the size of their savings, and whether predictability or potential outperformance matters more.
How each product works
NS&I Premium Bonds. Backed 100% by the UK Treasury. No interest paid. Each £1 bond is entered into a monthly prize draw. Prizes range from £25 to £1 million. Current annual prize fund rate is 4.40%, meaning the total prizes paid across all bonds equate to that percentage of the total eligible holdings. Individual returns vary widely - some holders win multiple prizes, others win nothing. Minimum holding £25, maximum £50,000. Tax-free.
Cash ISA. Offered by banks, building societies, and NS&I itself (the Direct ISA). Interest is paid at a guaranteed rate, fixed or variable. Fully protected by the Financial Services Compensation Scheme (FSCS) up to £85,000 per person per institution. Annual allowance of £20,000 in 2026-27. Interest is tax-free within the wrapper. Best buy easy access cash ISA rates in June 2026 are around 4.5 to 5%, depending on provider and access conditions.
Who benefits most from Premium Bonds
Premium Bonds tend to make the most sense for: higher and additional rate taxpayers who have already used their Personal Savings Allowance (£500 for higher rate, nil for additional rate in 2026-27); savers with more than £85,000 in savings who want Treasury-backed protection above the FSCS limit; and savers who value the possibility of winning a large prize over a guaranteed return.
For a basic rate taxpayer with savings below £20,000 who has not used their ISA allowance, a best-buy cash ISA is likely to produce a higher and more predictable return than Premium Bonds at current prize fund rates.
The tax position in 2026
The Personal Savings Allowance (PSA) in 2026-27 allows basic rate taxpayers to earn £1,000 of interest tax-free, and higher rate taxpayers to earn £500. Additional rate taxpayers have no PSA. Savers whose interest income exceeds their PSA will pay tax on the excess at their marginal rate, making tax-free products like ISAs and Premium Bonds more attractive.
With the Bank of England base rate at 3.75% and savings rates well above 4%, many savers with balances above £25,000 are now exceeding their PSA for the first time in years, making the tax treatment of savings products more relevant.
For UK personal finance guides, mortgage rates, and money news visit kaeltripton.com.
This article is for informational purposes only. All facts sourced from publicly available reports at time of publication, 2 June 2026.
Sources: NS&I Premium Bonds terms at nsandi.com; HMRC Personal Savings Allowance guidance at gov.uk; FSCS deposit protection at fscs.org.uk; Moneyfacts savings rate data, June 2026.
