All about Premium Bonds

Find out the power behind ERNIE, our heritage and Premium Bonds today

ERNIE, our Electronic Random Number Indicator Equipment, is the power behind Premium Bonds. Generating the numbers for 476.5 million tax-free prizes worth approximately £20.5 billion.

The next generation

The power behind Premium Bonds has now been upgraded to the next generation – ERNIE 5. Unlike previous versions which used thermal noise to produce random numbers, ERNIE 5 is powered by quantum technology, which uses light. This new technology allows ERNIE to produce enough random numbers for a monthly prize draw in just 12 minutes – 42.5 times faster than its thermal predecessor at the end of its number-generating career.

The clever bit

Using light, ERNIE 5 generates random numbers that are matched against eligible Bond numbers to determine the lucky winners. And because it’s random, every Bond number, whether it has 8, 9, 10 or 11 digits, has a separate and equal chance of winning a prize.

One in a million

Our Agents Million have the important task of delivering the winning news in person to the two monthly jackpot winners. Since the first Premium Bonds millionaire in 1994, over 400 new millionaires have been paid a visit.

Proud heritage

A Bletchley Park code breaker invented the first ERNIE in 1956. Following this, Harold Macmillan announced the launch of Premium Bonds on Budget Day, 17 April 1956, offering everyone an alternative way to save. Since then, there have been five generations of ERNIE and with continuous advances in technology, each has become faster and more powerful.

Find out more

Premium Bonds today

There are now more ways than ever to check, manage and buy Premium Bonds. Anyone can see if they have won a prize by using our online prize checker or app. And of course you can buy more Bonds whenever you like, 24 hours a day.

If you have won a Premium Bonds prize we'd love to hear from you