Both ISAs and premium bonds offer tax-free returns, but beyond that headline similarity they work in very different ways and suit different types of savers. Understanding how each works, the returns you might expect, and the risks involved can help you decide which is right for you, or whether a mix of both makes more sense.
What is the difference between an ISA and premium bonds?
A good place to start when considering an ISA or premium bonds is to understand their key characteristics. An ISA, or Individual Savings Account, is a wrapper that allows savings or investments to grow tax free. Within that wrapper, your money can sit in different formats, such as Cash ISAs or Stocks & Shares ISAs.
Premium bonds, by contrast, are a single savings product issued by the government’s National Savings. Instead of earning a predictable rate of interest, bondholders are entered into a monthly prize draw, with the chance of winning monthly prizes ranging from £25 to £1mn. So, while both are tax‑efficient, the mechanics – and outcomes – are different.
Are premium bonds classed as savings?
Yes, premium bonds as classified as savings. Your original capital is protected – backed by the UK government – just like savings accounts offered by National Savings. Another question that frequently gets asked is, do you get interest on premium bonds? The answer is no. Premium Bonds don’t earn interest. Instead, returns come entirely from the prize draw and are based on the odds of winning.
The widely quoted prize fund rate reflects the average return across all bondholders, but in reality, outcomes vary. Some people win regularly; others may win nothing at all. A holder with “average luck” will often earn less than competitive easy access savings or top cash ISAs, even though the returns are tax-free.
Cash ISA or premium bonds?
For many savers, the real comparison is between a Cash ISA or premium bonds. Both are low‑risk, capital‑secure options designed for short‑term or accessible savings.
A Cash ISA is a type of savings account held with a bank or building society. Your money earns interest at either a variable or fixed rate, giving more predictable returns than premium bonds. Rising interest rates have made cash ISAs more competitive in recent years, particularly for savers who value certainty.
Premium bonds, by contrast, offer excitement and the chance of winning large prizes, but potentially lower average returns. They can work well as a tax‑free complement, especially for higher‑rate taxpayers, or as an alternative if you prefer the lottery‑style element over certainty.
Read more: Are premium bonds a good investment?
Stocks and Shares ISA or premium bonds?
The comparison shifts when looking at Stocks & Shares ISA or premium bonds. A Stocks & Shares ISA is designed for long‑term investing rather than short‑term saving. Your money is invested in assets such as shares, funds and bonds, meaning shares ISAs carry ups and downs along the way.
Over the long term, however, the stock market has historically delivered much higher returns than cash or premium bonds, thanks to the compounding of growth and dividends – income payments to shareholders. This makes them better suited to longer‑term goals, such as retirement or wealth building ahead of inflation, provided you can tolerate volatility.
Read more: The power of compounding
Which offers the better return?
There’s no single answer to whether premium bonds or an ISA offers the better return. It depends on the type of ISA and your time horizon. Premium bonds rarely outperform competitive Cash ISAs for savers with “average luck”, and they don’t typically keep up with long‑term inflation unless you’re fortunate enough to win a big prize. Stocks & Shares ISAs, on the other hand, offer the stronger long‑term return potential, but come with market risk and there’s a chance you could get back less than you invest.
For short‑term savings and emergency funds, premium bonds or Cash ISAs make sense. For long‑term investing and wealth building, Stocks & Shares ISAs generally deliver better financial outcomes over time. For many people, the answer isn’t choosing one over the other but using each for what it does best.
Read more: I’ve used my max ISA allowance – what should I do next?
Nothing on this website should be construed as personal advice based on your circumstances. No news or research item is a personal recommendation to deal.
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