The NS&I premium bonds prize fund rate will rise from 3.8% to 4.35% from September’s draw, the government-backed savings bank announced on 18 August 2026, the highest rate since December 2024, according to MoneySavingExpert.
This is the second increase in two months. The July rise, from 3.3% to 3.8%, was itself the first upward move in almost three years, following a long run of consecutive cuts.
I think the pace matters here. NS&I has a net financing target of £15 billion for the 2026–27 financial year, with a permitted variance of £4 billion either way. Two rate increases in quick succession, accompanied by broadened changes to Direct Saver, Income Bonds, and British Savings Bonds, suggest the organisation is running behind where it wants to be, and is using rate policy to close the gap.
What the premium bonds prize fund increase actually means for holders
The odds of winning with each £1 bond number improve from 22,000-to-1 to 21,000-to-1. NS&I estimates there will be 308,000 more prizes in the September draw than in August, pushing the prize pot up by roughly £63m to £497m.
According to NS&I’s monthly prize allocation data, the September draw is expected to contain 6,533,031 prizes worth £497,326,725, compared with 6,224,837 prizes worth £433,663,565 in August.
The composition of that prize pot shifts upward. The number of £100,000 prizes rises from 83 to an estimated 95; £50,000 prizes go from 165 to 192; and £25,000 prizes increase from 331 to 382. Meanwhile, £100 and £50 prizes each jump from 1,931,214 to an estimated 2,366,135. The trade-off: £25 prizes are cut from just under 2.3 million to roughly 1.7 million.
NS&I Retail Director Andrew Westhead said in the official press release: ‘The September Premium Bonds draw is now expected to have more than 6.5 million tax-free prizes worth over £497 million. Premium Bonds continue to offer over 22 million savers of all ages the monthly excitement of tax-free prizes with 100% security backed by HM Treasury, and the flexibility to withdraw at any time.’
The tax argument holds, but only above a certain holding size
Premium bonds pay no interest. What they offer instead is a monthly lottery funded by that prize fund rate. For a higher-rate taxpayer holding the maximum £50,000, winning the equivalent of 4.35% would produce £2,175 completely tax-free. That compares well against a taxed savings account, once you account for the personal savings allowance of £500 for higher-rate taxpayers.
The problem is that the 4.35% figure is a prize fund rate, not a guaranteed return. Caitlyn Eastell, an analyst at Moneyfactscompare.co.uk, says it ‘shouldn’t be mistaken for a headline rate’. She adds: ‘With the cost of living continuing to weigh on household budgets, it’s understandable savers may not want to leave their returns to chance.’
The easy-access comparison is stark. Top standard easy-access savings accounts currently pay 4.5%, according to MoneySavingExpert, guaranteed, not probabilistic.
Sarah Coles at AJ Bell welcomes the rate increase but is clear-eyed about what it changes: ‘It doesn’t change the fact that in an average month the average bond holder will win nothing.’ Those with smaller amounts invested are even less likely to see any return at all.
AJ Bell’s freedom of information research found that just under 14.4 million current holders, roughly 63% of all Premium Bond savers, have never won a single prize. Fewer than 1% of all prizes paid out between February 2025 and January 2026 went to accounts holding less than £1,000.
The lottery structure means concentration at the top. Larger holdings generate more monthly tickets; the probabilistic return converges toward the prize fund rate only with meaningful scale. For smaller savers, the September improvements are unlikely to change outcomes in any practical sense.
The ISA angle could reshape who holds Premium Bonds
From 6 April 2027, savers aged under 65 will face a £12,000 cap on cash ISA contributions, down from the current £20,000 overall ISA allowance. For savers who have used up their ISA headroom, or who will exceed their personal savings allowance (£1,000 for basic-rate taxpayers, £500 for higher-rate), Premium Bonds become a more rational home for cash. The tax-free treatment does real work for those savers, even if the return is uncertain.
According to Yahoo Finance, citing NS&I data, Premium Bonds have now paid out over £40 billion in prizes since their launch in November 1956, with more than £4.95 billion distributed across 71.7 million prizes in 2025 alone.
NS&I’s financing target gives the rate story a useful anchor. If inflows remain below the £15 billion goal as the year progresses, a third increase before April cannot be ruled out. The July rise, detailed in the NS&I Adviser announcement, delivered an estimated 322,000 extra prizes per month compared with May. September builds on that. Whether the government’s savings arm needs to go further will depend on how much cash flows in over the autumn.
