Why Premium Bond prizes are tax-free
NS&I Premium Bonds are not classed as interest-bearing investments under UK tax law. The Bonds themselves earn no interest; instead, NS&I runs a monthly prize draw from the entire pool of issued Bonds. Prizes are paid by HM Treasury and are explicitly exempted from income tax under section 692 of the Income Tax (Trading and Other Income) Act 2005. They are also exempt from capital gains tax — the Bond's underlying value is always £1, so no gain or loss can occur.
This means:
- Prizes do not use any of your Personal Savings Allowance.
- Prizes do not appear on self-assessment.
- Prizes do not affect your tax band or push you into higher rate.
- You do not need to report wins to HMRC, regardless of size — even the £1,000,000 top prize is paid net of tax (i.e. fully tax-free).
- Holdings are repaid at face value with no CGT on encashment.
However, Premium Bonds do count as part of your estate for inheritance tax purposes and are paid into the deceased's executors. They are also visible on the means-test for benefits and for university maintenance loan calculations.
How the prize fund rate compares to taxed savings
The 3.80% prize fund rate (announced from April 2025 onwards) is the average return assuming average luck — not a guaranteed yield. The actual return for any individual holder varies wildly because the prize distribution is heavily skewed: most prizes are £25, but two £1,000,000 prizes inflate the mean. With a £50,000 holding (the maximum), the median real-world return is closer to 3.4% according to NS&I's own probability data, while a £1,000 holding may go years without winning anything.
For tax comparison, a 3.80% Premium Bond return is equivalent to:
- A 3.80% taxable bond for non-taxpayers (within Personal Allowance + starter band + PSA).
- A 4.75% taxable bond for basic-rate (20%) taxpayers above their PSA.
- A 6.33% taxable bond for higher-rate (40%) taxpayers above their PSA.
- A 6.91% taxable bond for additional-rate (45%) taxpayers (PSA = £0).
So Premium Bonds are most attractive to higher and additional-rate taxpayers who have already filled their ISA allowance — the 6.33% gross-equivalent yield is hard to beat from instant-access cash savings in 2025.
Three worked examples (UK 2025/26)
Example 1: £50,000 holding for additional-rate earner
Olivia is an additional-rate earner with £150,000 salary and £30,000 dividends. Her PSA is £0. She holds the maximum £50,000 in Premium Bonds.
Calculation: Expected average annual prize £50,000 × 3.80% = £1,900 tax-free. The same £50,000 in a 5% taxable bond would produce £2,500 gross, £1,375 net (45% tax). Premium Bonds give her £525 more per year tax-free, plus prize-draw upside.
Example 2: £10,000 holding for retiree
Brian, age 75, has State Pension £11,973, no other income, and £10,000 in Premium Bonds. He pays no income tax.
Calculation: Expected prize £10,000 × 3.80% = £380 tax-free. A 4.5% taxable bond would also be tax-free for Brian (within his starter band + PSA), producing £450. Premium Bonds make sense only if he values the lottery upside or wants near-zero risk; otherwise a fixed-rate bond produces a higher certain return.
Example 3: Median outcome on £25,000
Robert holds £25,000 in Premium Bonds. The 3.80% mean implies £950/year, but NS&I's median data shows the most likely outcome is £825–£900 in a typical 12-month period. The variance reflects the prize structure: lots of £25 wins, fewer £100s, occasional £500+, vanishingly rare £100k+.
Tax outcome: All wins, whether £25 or £1,000,000, are £0 tax.
Common mistakes to avoid
- Assuming Premium Bond prizes count toward your PSA — they do not, the £1,000 PSA remains fully available.
- Selling Premium Bonds to fund an ISA but forgetting NS&I cancels Bonds at face value — no CGT, but no growth either.
- Buying for a child without a grandparent gift — children can hold up to £50,000 from age 16; under 16, parents/guardians can hold on their behalf.
- Confusing Premium Bonds with NS&I Direct Saver — Direct Saver pays interest taxable under the PSA.
- Believing larger holdings give higher per-£ returns — the rate is uniform; only chance of winning the top prize scales with holding size.
- Forgetting Bonds are means-tested for benefits — Universal Credit, Pension Credit, and student maintenance assessments include their value.
When to use this calculator
Use this calculator if you are an additional-rate or higher-rate taxpayer who has already maxed out the £20,000 ISA allowance and is considering where to park further cash savings. Premium Bonds also suit savers who want absolute capital security (HM Treasury-backed, no FSCS limit needed) plus tax-free upside. Use it before each NS&I rate change to recompare against fixed-rate bonds, and re-run after any pay rise that changes your marginal tax band.
Regional differences (Scotland, Wales, Northern Ireland)
Premium Bonds are UK-wide and identical for residents of England, Scotland, Wales, and Northern Ireland. Prize draws and tax exemption are the same. Scottish income tax bands do not affect Premium Bond prizes because the prizes are not classed as income for tax purposes. Crown Dependencies (Isle of Man, Channel Islands) cannot hold UK Premium Bonds — they are restricted to UK tax residents.