Premium Bonds: how the monthly prize draw works, the odds and the limits
Published · 5 min read · Figures checked . UK rules and rates change, so check the official sources below before you act.
Premium Bonds pay no interest. Instead, each £1 Bond is entered into a monthly prize draw. This guide explains the 4.35% prize fund rate, the 21,000 to 1 odds, the £50,000 limit and what tax-free means.
What Premium Bonds are and how the draw works
Premium Bonds are a savings product from NS&I (National Savings and Investments), which is backed by HM Treasury. Unlike a normal savings account they do not earn interest. Each £1 you hold is one Bond number, and every month a computer called ERNIE (Electronic Random Number Indicator Equipment) generates random numbers that decide which Bond numbers win prizes. Prizes range from £25 to £1 million. Bonds must be held for a whole month before they are eligible, so NS&I's own example is that Bonds bought in November enter the January draw. GOV.UK describes the latest version, ERNIE 5, as using quantum technology, and says the Government Actuary's Department tests the output each month and issues a certificate before prizes can be paid. Your money is not locked away, and you can take it out at any time without a penalty, although the money can take a few days to reach your bank account.
The key figures and limits
You can buy from £25 and hold up to £50,000 in total. Anyone aged 16 or over with a UK bank account can buy Bonds for themselves. NS&I describes the prize fund rate as variable, so it can change at any time. It was 3.30% from April 2026, rose to 3.80% from the July 2026 draw, and rose to 4.35% from the September 2026 draw, according to NS&I press releases of 14 May and 18 August 2026. The odds shortened over the same period, from 23,000 to 1, to 22,000 to 1, and then to 21,000 to 1 for each £1 Bond in each monthly draw. The prize fund rate is the overall rate used to size the monthly prize pot. It is not what any individual holder is promised, because the money is paid out as many prizes of different sizes to different Bond numbers, and some holders win nothing in a month.
What the September 2026 draw looked like
NS&I's results for the September 2026 draw show 6,529,868 prizes worth £497,086,175, including two £1 million prizes, drawn from 137,127,223,215 eligible £1 Bonds. As a check on the prize fund rate, 4.35% a year is 0.3625% a month, and 0.3625% of £137.1 billion is about £497.1 million, which matches the prize total. NS&I's August release gave an estimated spread of prizes for September. Of an estimated 6,533,031 prizes, 2,366,135 were £100, 2,366,135 were £50 and 1,717,659 were £25. That is 6,449,929 prizes of £100 or less, or about 98.7% of the total. Only 95 prizes were estimated at £100,000, and 2 at £1 million. In practice, most prizes are small, and large prizes are rare.
A worked example
These figures are illustrative only. Suppose someone holds £1,000 in Premium Bonds, which is 1,000 Bond numbers. At odds of 21,000 to 1 per Bond, the average number of prizes per month is 1,000 divided by 21,000, or about 0.048, and over twelve months about 0.57. Treating each Bond as an independent chance, the probability of at least one prize in a given month is 1 minus (20,999 divided by 21,000) to the power of 1,000, which is about 4.65%, or roughly one month in twenty-one. Because the odds apply to each Bond separately, holding £50,000 gives 50,000 divided by 21,000, or about 2.4 prizes a month on average. At the 4.35% prize fund rate, £1,000 would average £43.50 a year in prizes across all holders and £50,000 would average £2,175, but any real holder's result can be well above or below that average, and these are not forecasts.
Tax, children and other points to know
Prizes are free from UK Income Tax and Capital Gains Tax, as NS&I and GOV.UK both state. Parents and guardians can buy Bonds for a child under 16 and manage them until the child turns 16, and anyone can give Bonds as a gift for someone else's child online or by post, with the child's total holding capped at £50,000. Prizes are normally paid into a bank account by around the 7th working day of the month, can be automatically reinvested, or can be sent by cheque, which takes longer. Winners of £25,000, £50,000 or £100,000 complete a claim form first. HMRC's manual says a prize counts for Inheritance Tax purposes only once the draw allocating it has taken place.
Common mistakes and what to weigh up
A common mistake is to read the prize fund rate as a guaranteed interest rate. Premium Bonds pay no interest, so the cash value of your Bonds stays at £1 per Bond and the outcome depends on luck. NS&I's own page reminds savers that inflation can reduce the real value of money over time. Another slip is forgetting the one-month wait, so new Bonds do not enter the very next draw. NS&I's online prize checker, app and Alexa skill let you check a holder's number for prizes, so it can be worth checking them regularly. Some savers compare the prize fund rate with the interest on other accounts, and the personal factors that matter include the tax rules, how much is held, and how much you need to keep easily accessible. Free, impartial help is available from MoneyHelper.
Check before you act
Rates, odds and prize numbers change, often monthly, and your own circumstances decide what suits you. This guide is general information, not personal advice, so confirm the current figures on the official pages linked below before buying or withdrawing Bonds.
Sources
For information only. See our disclaimer and editorial standards. Spotted an error? Tell us.
