Premium Bonds Explained: Odds, Prizes and Is It Worth It?
Quick answer
Premium Bonds swap interest for a monthly tax-free prize draw, backed by HM Treasury. We explain how they work, the real odds, the prize fund rate and who they actually suit.
Premium bonds are one of the UK's best-loved ways to save, with more than 22 million people holding them. Instead of earning interest, your money is entered into a monthly prize draw where you could win anything from £25 to £1 million — all completely tax-free. But the trade-off is real: many savers earn nothing at all in a given year, so it pays to understand exactly how they work before you commit.
This guide explains how premium bonds work, what the odds and prize fund rate really mean, and — crucially — whether they're worth it for you compared with an ordinary savings account.
What are premium bonds?
Premium bonds are a savings product run by National Savings & Investments (NS&I), a state-owned bank that is backed by HM Treasury. That backing matters: your money is 100% secure. Unlike a high-street bank account, which protects you up to £85,000 under the Financial Services Compensation Scheme, every penny you put into premium bonds is guaranteed by the government, however much you hold.
Here's the key difference from a normal savings account: premium bonds don't pay interest. Instead, the interest that would have been paid across all bondholders is pooled together and given away as prizes in a monthly draw. Each £1 you invest buys one bond, and each bond is a separate entry into the draw with its own unique number. The more bonds you hold, the more entries you have — and the better your chances of winning.
You can buy premium bonds from £25 (the minimum purchase), and you can hold up to a maximum of £50,000 per person. Children can hold them too, bought by a parent, guardian or grandparent.
How the monthly draw works
Every month, an electronic random number generator affectionately known as ERNIE (Electronic Random Number Indicator Equipment) picks winning bond numbers at random. Prizes range from £25 up to two top prizes of £1 million each month. Bonds must have been held for a full calendar month before the next draw to be eligible, so newly bought bonds wait one cycle before they start playing.
Winnings can be paid straight into your bank account, or reinvested to buy more bonds (up to the £50,000 limit), increasing your future chances. You can check whether you've won using the NS&I prize checker, the official app, or Alexa.
The prize fund rate — what it actually means
NS&I publishes a headline figure called the premium bonds prize fund rate. This is the annual rate of interest that the total prize fund represents across all bonds in the draw. If the prize fund rate is, say, 3.8%, it means NS&I is paying out the equivalent of 3.8% of all the money invested, spread across the prizes.
This is the single most misunderstood number in personal finance. The prize fund rate is an average across millions of bondholders — it is not a return you are guaranteed, or even likely, to earn yourself. A handful of people win large prizes that pull the average up, while a great many win nothing at all. Your personal return could be 0%, it could match the rate, or — if you're lucky — it could be far higher.
The prize fund rate changes from time to time as NS&I adjusts payouts in response to wider interest rates, so always check the current figure on the NS&I website rather than relying on a number you saw last year.
Premium bonds odds: your real chances
The premium bonds odds are quoted per £1 bond, per monthly draw. Currently the odds are around 22,000 to 1 that any single £1 bond wins any prize in a given month — though NS&I changes these odds periodically, so treat that as a guide and check the latest figure on the NS&I site.
At first glance 22,000 to 1 sounds bleak, and for one bond it is. But remember you hold many bonds at once. Someone with £1,000 holds 1,000 separate entries every single month; someone with the full £50,000 holds 50,000 entries. The odds compound across your holding and across the year, which is why the size of your holding changes everything.
Use the Premium Bonds Calculator above to estimate the typical, most-likely annual win for a given holding — it's far more honest than the headline prize fund rate for working out what you might realistically expect.
Is it worth it? — a worked example
Let's make this concrete. Imagine the prize fund rate is around 3.8% and odds of roughly 22,000 to 1 per bond per month.
| Holding | What the "average" rate implies | What most people realistically get |
|---|---|---|
| £1,000 | ~£38 a year | Often £0 — many months you win nothing; a typical year may bring one £25 prize, or none |
| £10,000 | ~£380 a year | Around £200–£300 for a typical holder — below the headline rate |
| £50,000 (max) | ~£1,900 a year | Closer to the prize fund rate, often a few hundred pounds below it |
The pattern is clear: the smaller your holding, the more misleading the average return. With £1,000 you simply don't hold enough bonds for the law of averages to work in your favour, so the most likely outcome is winning little or nothing. Only once you hold tens of thousands of pounds do your actual winnings start to drift close to the published rate — and even then they usually land a notch below it.
This is the heart of premium bonds vs savings: a normal savings account pays its advertised rate on every pound, predictably, every year. Premium bonds pay a lottery. To decide which wins for you, the deciding factor is usually tax.
Premium bonds and the Personal Savings Allowance
Premium bond prizes are completely tax-free — you never declare them and never pay tax on a win, however large. Ordinary savings interest, by contrast, is taxable, though most people have a buffer called the Personal Savings Allowance (PSA):
- Basic-rate (20%) taxpayers: £1,000 of savings interest tax-free each year
- Higher-rate (40%) taxpayers: £500 tax-free each year
- Additional-rate (45%) taxpayers: £0 — no allowance at all
This is the crux of whether premium bonds make sense. If your savings interest stays within your PSA, you're paying no tax on it anyway, so the tax-free status of premium bonds gives you no advantage — and a guaranteed savings rate will almost always beat the premium bonds lottery. But if you've already used up your PSA, every extra pound of normal interest is taxed at your marginal rate, and the tax-free prize draw suddenly looks much more attractive.
| Premium bonds | Normal savings account |
|---|---|
| 100% safe (HM Treasury backed, no £85k cap) | Protected to £85,000 per bank (FSCS) |
| Returns are a tax-free lottery — could be £0 | Predictable interest paid on every pound |
| Prizes always tax-free | Interest taxable above your PSA |
| Chance (small) of life-changing £1m | No jackpot, but reliable growth |
| Easy to cash in, no penalty | Easy access or fixed terms available |
Who premium bonds suit — and who they don't
Premium bonds may suit you if…
- You're a higher- or additional-rate taxpayer who has used up your PSA, so tax-free returns genuinely beat a taxed savings account.
- You want complete safety for a large sum — above £85,000 the Treasury backing is reassuring.
- You enjoy the flutter: the small monthly thrill and the (tiny) dream of £1 million, without risking your capital.
- You've already maxed your ISA allowance and want another tax-efficient home for cash.
You're probably better off elsewhere if…
- Your savings interest sits comfortably within your PSA — a guaranteed rate will likely out-earn the bonds.
- You have a small holding (a few hundred or low thousands) — the odds mean you'll probably win nothing.
- You're relying on the money to grow predictably, for example towards a deposit or a known bill.
- You haven't yet built an emergency fund in an easy-access account paying reliable interest.
Compare the latest guaranteed rates on our best savings account interest rates guide before deciding.
Common misconceptions
"The prize fund rate is what I'll earn"
No. It's an average across millions of bondholders, skewed upward by big winners. Your personal return is very likely to be lower — often zero on a small holding.
"Holding for years means I'm bound to win eventually"
Each draw is independent and random. Past months don't improve future odds. A small holding can genuinely go years without a single prize.
"It's basically a free lottery, so there's no downside"
The downside is the opportunity cost: every month your money isn't winning, it's also not earning the guaranteed interest it could have made elsewhere. With inflation, money that wins nothing is quietly losing value.
"Premium bonds aren't taxed, so they always beat savings"
Only true once you've used your PSA. If your interest is already tax-free under the allowance, the bonds' tax advantage is worthless — and a normal account's certainty usually wins.
FAQs
Are premium bonds safe?
Yes. They're run by NS&I and backed by HM Treasury, so 100% of your money is secure with no upper limit on protection — unlike the £85,000 FSCS cap that applies to ordinary bank accounts.
Do I pay tax on premium bond prizes?
No. All prizes are completely tax-free and you never have to declare them. This is their main advantage over a normal savings account once you've used your Personal Savings Allowance.
What's the minimum and maximum I can hold?
The minimum purchase is £25 and the maximum holding is £50,000 per person. Children can hold bonds too, bought on their behalf by a parent, guardian or grandparent.
What are the odds of winning?
Currently around 22,000 to 1 per £1 bond, per monthly draw — but NS&I changes the odds periodically, so check the NS&I website for the latest figure. The more bonds you hold, the more entries you have.
Can I cash in my premium bonds whenever I want?
Yes. There's no fixed term and no penalty — you can withdraw some or all of your holding at any time, usually within a few working days. Use our Savings Calculator to compare what a guaranteed rate would give you instead.
Sources
- NS&I — Premium Bonds
- MoneyHelper — Premium Bonds explained
- GOV.UK — Tax on savings interest (Personal Savings Allowance)
This guide is general information, not personal financial advice. For your own circumstances, speak to a qualified adviser.
Written by
Laura Michelle Davis — Chartered Tax Adviser (CTA)
ACCA · CTA (Chartered Tax Adviser) · ATT · BSc Economics, UC Berkeley
Laura Michelle Davis is a Chartered Tax Adviser (CTA) who also holds the ACCA and ATT qualifications and a BSc in Economics from UC Berkeley. She specialises in UK personal tax, covering income tax, National Insurance, self-employment and capital gains, and has built her career making complicated rules easy to follow. At TaxFly, Laura writes and edits the tax guides and explainers, checking that figures reflect current HMRC rates and that every explanation answers the question a real person is actually asking. Her goal is plain-English clarity you can trust and act on.
