NS&I uses cookies which are essential for this website to operate. You may delete and block our cookies but parts of this website will no longer work.
By using this website you accept our use of cookies. See our cookie policy for more on our cookies and how to manage them

Our savings and investments - The history of ERNIE and Premium Bonds


ERNIE stands for Electronic Random Number Indicator Equipment and he was invented in 1956 by one of the original Bletchley Park code breakers.

The history of ERNIE and Premium Bonds

Budget day, 17 April 1956, and Harold Macmillan announced the launch of Premium Bonds. The intention was to reduce inflation and encourage those who might find prize-winning more appealing than interest to save their money.

The first Premium Bond was bought on 1 November 1956 by Alderman Sir Cuthbert Ackroyd - who later became Lord Mayor of London. By the end of that first day, £5 million worth of Premium Bonds had been sold.

With £82 million invested, the first draw happened the following year on Saturday 1 June 1957 at Bond headquarters in Lytham St. Anne's, Lancashire and by the end of August that year, £100 million had been invested. There were 23,000 prizes in that first draw with a top prize of £1,000.

Premium Savings Bonds on sale here

November 1956: Customers sign up for Premium Savings Bonds

Ernie machine

Postmaster-General Ernest Marples
starting the first draw.

Who is ERNIE?

No one's really sure whose idea it was to use ‘ERNIE' to represent ‘Electronic Random Number Indicator Equipment', but he's central to the concept of Premium Bonds because he produces all the winning numbers.

Since 1957, four generations of ERNIE have produced the numbers for over 290 million tax-free prizes worth approximately £15 billion.

The basic function of each ERNIE machine has not changed but, with continuous advances in technology, each ERNIE has been replaced by a faster and smaller model to keep pace with Premium Bonds demand.

Ernie Circuit board

Engineers working on ERNIE 1's

Premiumn Bonds Winning numbers

Lord Mackintosh holding up the first ever jackpot winning number


ERNIE 1 used to take 52 days to complete a draw, today ERNIE 4 takes a mere two and a half hours. Introduced in April 2004 because Premium Bonds were becoming so popular, ERNIE 4 was also going to need to produce 11-digit Bond numbers.

After testing, Ernie 4 received full accreditation for generating all Bond numbers at random, no matter how long. So every Bond number, whether it has eight, nine, 10 or 11 digits has a separate and equal chance of winning a prize.

Ernie Website

Buying Premium Bonds
via the Internet

Science Museum

Launch of ERNIE 4 at the
Science Museum.

Premium Bonds in the 21st Century

Since 2010 we’ve given customers more ways to manage and check their Premium Bonds.

Anyone can check if they have won a prize by using the prize checker on our website or through our prizechecker app.

When you register for our online and phone service you can arrange to have your prizes paid directly into your bank account instead of waiting for a warrant (like a cheque) to arrive in the post. And of course, you can buy more Bonds whenever you like, 24 hours a day.

Common myths

ERNIE is so famous that he receives Christmas and Valentine cards every year. And, as is the case with many a celebrity figure, over the years some myths have grown up around ERNIE and Premium Bonds. Here are a few of them debunked!

Want more information? Find out how to invest ›