Reacting to ‘Premium Bonds prize rate to rise to 4.35% – how do they compare?’, MoneySavingExpert, 18 August 2026. The underlying figures in this piece are taken directly from NS&I's own published rates and its historical rate table, checked on 19 August 2026.
Premium Bonds are about to have their best headline rate since early 2024, and the number being reported — 4.35% — is real. NS&I is genuinely raising the prize fund rate, genuinely improving the odds, and genuinely paying out more than it did last month. Our problem is not with the number. It is with what almost every household will assume the number means.
Here is the thing worth understanding, and it is the whole point of this piece: 4.35% is not a return. It is the size of the prize pot. Nobody is credited 4.35%. The money is paid out as prizes ranging from £25 to £1 million, and the distribution of those prizes is so lopsided that the typical holder receives roughly a third of the advertised figure. A savings rate tells you what you will get. A prize fund rate tells you what the pot contains before it is shared out very unevenly indeed. Treating one as the other is the most expensive reading error in British personal finance, and every rate rise reprints it in the headlines.
What actually changed
From the September 2026 draw, NS&I's prize fund rate rises to 4.35% and the odds improve to 21,000 to 1 for every £1 Bond. That is up from 3.80% and 22,000 to 1, which applied from the July 2026 draw. NS&I's own historical table shows how much this has moved in a single year: 3.30% in April 2026, 3.80% in July, now 4.35% in September. Prizes stay tax-free, the minimum stays £25, the maximum holding stays £50,000.
The rise is striking because it runs against the direction of the Bank of England's Bank Rate, which has been 3.75% since 18 December 2025. NS&I is not tracking the base rate here. It has an annual amount it needs to raise for the Treasury, and when it is behind, it pays up. That is useful context for savers: this rate moved because of NS&I's funding needs, not because savings rates generally went up, and it can move back for the same reason.
Why the typical holder gets about a third of the headline
The arithmetic is straightforward once you see it. The prize fund is 4.35% of the total value of all Bonds in the draw. The number of prizes is fixed by the odds — one prize per 21,000 Bond numbers per month. Divide the pot by the number of prizes and you get the average prize: about £76.
But the average prize is not the usual prize. The overwhelming majority of prizes paid out every month are the £25 minimum, and the £76 average is dragged upwards by two £1 million prizes a month and the tiers of £100,000, £50,000 and £25,000 beneath them. If your wins are all £25 — and for most households they will be — you receive £25 for every £76 of average, which is 33% of the advertised rate. That is about 1.43% a year, not 4.35%.
Illustrative, using NS&I's published September 2026 odds of 21,000 to 1. Prize outcomes are random and yours will differ.
- Bond numbers held: 10,000 — every £1 is its own entry.
- Expected prizes per month: 10,000 ÷ 21,000 = 0.48.
- Expected prizes per year: about 5.7.
- If every one is the £25 minimum: about £143 a year, tax-free — an effective 1.43%.
- What 4.35% on £10,000 would be: £435.
The £292 difference has not disappeared. It is being paid to the small number of holders who win the large prizes. Occasional bigger wins lift the realistic figure somewhat above £143 — but the gap to £435 is structural, not bad luck.
For comparison, on the same £10,000 over a year, NS&I's own Direct ISA at 3.80% tax-free pays £380, its Direct Saver at 3.75% pays £375 gross, and its one-year Guaranteed Growth Bond at 4.82% pays £482 gross but locks the money away. All rates as published by NS&I on 19 August 2026.
The small-holder problem nobody mentions
The lower your holding, the further your likely experience drifts from the headline. Work NS&I's 21,000 to 1 odds through for someone holding £1,000: the chance of winning nothing in a given month is about 95%, and compounded across twelve draws, the chance of winning nothing whatsoever in an entire year is about 56%.
Read that again, because it is the sentence the rate rise headlines leave out. A person with £1,000 in Premium Bonds is more likely than not to finish the year with exactly £1,000. Meanwhile the same £1,000 in an account paying 3.80% would have produced £38 with certainty. At £5,000 the picture improves — about a 6% chance of a blank year — and at the £50,000 maximum you would expect roughly 28 prizes a year, though still overwhelmingly £25 ones.
What Premium Bonds are genuinely good at
None of this makes them a bad product. It makes them a misdescribed one. Three things about Premium Bonds are genuinely excellent and worth saying plainly.
First, security. NS&I is backed by HM Treasury, so 100% of your money is protected however much you hold. That matters above the Financial Services Compensation Scheme limit of £120,000 per person per firm, which rose to that level on 1 December 2025. For someone holding a large cash sum after a house sale or an inheritance, that is a real and rare feature.
Second, the prizes are tax-free and never touch your Personal Savings Allowance — £1,000 of interest for a basic-rate taxpayer, £500 for higher-rate and £0 for additional-rate, per GOV.UK for 2026-27. If you are a higher-rate taxpayer already using up your £500, that exemption has genuine value.
Third, people actually keep money in them. The monthly flutter is a real behavioural feature: plenty of households leave Premium Bonds alone for years in a way they never manage with an easy-access account. A slightly lower expected return you do not raid beats a higher one you spend. Our guide on building a savings habit that survives is about exactly that trade.
What this means for your household this week
The coaching question is not ‘are Premium Bonds good?’ It is ‘what is this particular money for?’ — and Premium Bonds answer that question well for exactly one job and badly for most others.
If the money is your emergency fund, the thing that matters is access and certainty, and a 56% chance of a blank year at £1,000 is the opposite of what you want compounding quietly in the background. If it is money for something dated — a car in eighteen months, a wedding, a deposit — you need to know what it will be worth, and Premium Bonds structurally cannot tell you. If it is genuinely surplus money, already sitting above a funded emergency fund, and you like the monthly lottery ticket, then the trade is honest and you are making it with your eyes open.
The one group who should look hardest at this are the people holding a substantial sum in Premium Bonds who have never used their ISA allowance — £20,000 for the 2026-27 tax year. They are paying for a tax exemption twice over: once in a lower expected return, and again by leaving a perfectly good tax-free wrapper unused. Our plain-English guide to how ISAs actually work covers the ground in ten minutes.
Two things worth doing this week
1. Check for unclaimed prizes. NS&I holds a large stock of prizes nobody has claimed, mostly because people moved house and never updated their details. The official NS&I prize checker takes about a minute and needs only your holder's number. Do it for any Bonds bought for children too — those are the ones that go stale.
2. Work out your actual tax position on savings interest. Before deciding a tax-free wrapper is worth a lower return, find out whether you are paying any tax on savings at all. The GOV.UK guide to tax on savings interest sets out the Personal Savings Allowance and the starting rate for savings, which gives up to £5,000 of tax-free interest to people whose other income is under £17,570. Plenty of households discover the exemption they were paying for was one they never needed.
What is still uncertain
Two things. The prize fund rate is variable and NS&I can change it at any time — it has already moved three times in 2026, from 3.30% in April to 3.80% in July to 4.35% in September. Anyone treating 4.35% as a rate they have locked in has misread it twice over. And NS&I sets these rates against a funding target agreed with the Treasury, so the next move depends on how its inflows are running rather than on anything the Bank of England does. The September draw takes place at the start of September, and NS&I publishes the full prize breakdown alongside it — that is when the number of £25 prizes versus larger ones becomes visible for this rate.
Where coaching ends and advice begins. Understanding what a prize fund rate is, working out what your money is for, and knowing your own tax position — that is coaching, and it is all here. Recommending a specific savings product, provider or investment for your circumstances is regulated financial advice. Buzz Money Coach is a trading style of Buzz Money Ltd, which is not authorised to give regulated advice and does not. Where you need it, we say so and can introduce you to Equity & General, authorised and regulated by the FCA (No. 474163) — entirely optional, with no obligation, and E&G pays us a commission on introductions that convert. For free, independent guidance, MoneyHelper is the government-backed service. If money is a worry right now, start here instead — StepChange and National Debtline give free help today.
Premium Bonds at 4.35% are a better deal this September than they were in August. They are still not a 4.35% savings account, and no rate rise will ever make them one. Know which of your money is buying certainty and which is buying a monthly chance, decide that on purpose rather than by drift, and the headline stops being able to mislead you. If you are not sure which of your pots is doing which job, our Financial Freedom Score is the quickest way to find out.