How lucky are YOUR Premium Bonuses? We investigate why some numbers and letters seem more likely to win the £1 million jackpot

Premium bonuses are surrounded by beliefs about how lucky – or unlucky – individual bonuses are, but are some really more likely to hit the jackpot than others?

Bonds are National Savings and Investments’ most popular savings option and there are more than 120 billion of them in existence.

The way they work is that each bonus is entered into a monthly lottery. Instead of paying interest like a standard savings offer, Premium Bonds offer the chance to win prizes ranging from £25 up to the coveted £1 million jackpot, of which there are two each month.

This element of chance, combined with the fact that bonds have been around since 1956, has given rise to a number of superstitions about some bonds being luckier than others.

Common beliefs are that new Premium Bonuses are luckier than old ones, or that certain areas are more likely to win than others.

These myths have been debunked by NS&I, which says the draw is entirely random and if an area has more jackpot winners then it must have more bondholders.

But are some premium bonuses luckier than others? And is there a way to tell if you have a “lucky” bonus or not?

This is Money put this theory to the test by analysing the bonds that won the £1 million jackpot over the past two years.

Each voucher is assigned an 11-digit code, consisting of nine numbers from 0 to 9 and two letters from A to Z.

Since the Premium Bonus draw is meant to be random, one might assume that the winning bonuses had a fairly even distribution of these letters and numbers.

But you would be wrong.

In fact, over the past two years some bills have become much more likely to appear in winning bonds than others.

For example, the letters A, I, OU and Y did not appear in any jackpot-winning Premium Bonus during the period.

But the letter B appeared on 9 percent of all winning bonuses, making it the luckiest letter.

The letters V, P and F appeared on 7 per cent of Premium Bonds that won a £1 million prize.

The chances of an individual number appearing in a winning Premium Bonus are much more equal, as there are only 10, rather than 26.

The unluckiest number was 7, which appeared in 24 percent of winning bonuses, even though 7 is a very commonly chosen “lucky” number.

The luckiest number was 3, which appeared in a whopping 40 percent of winning Premium Bonuses.

At first glance, this gives some bondholders cause to feel a little disheartened. If NS&I really does calculate winning bonds at random, why do some letters not appear at all in the last 24 months of £1m premium bond prizes?

The answer is probability.

Each number has a 90 percent chance of appearing in any winning Premium Bonus number, and each letter has a 7.6 percent chance.

In over 48 Premium Bonus draws, any number has a near certainty of appearing and each letter has a 97.8 percent chance.

But the probability of a letter not appearing at all in the 48 Premium Bond prize draws is still 2.14 percent, which explains why some of the recent winning bonds have “unluckier” letters.

An NS&I spokesperson said: “There are many myths surrounding Premium Bonds, including that some numbers and letters are luckier than others, but the truth is that every £1 Bond has an equal chance of being drawn each month.”

NS&I uses a computer called ERNIE to randomly calculate the winning Premium Bond numbers, and is scrutinised each month by the Government Actuary’s Department to ensure it does so fairly.