If you’ve been feeling a mite short of cash since the reality of New Year, new term set in then there’s every chance you’ve dug deep into your threadbare pocket and fished out pound;1 or more to try your luck on the National Lottery.

Frankly, the odds are so low for your financial woes being solved by a machine churning out brightly-coloured balls twice a week, you may as well be popping your coins down the proverbial pan.

But if you like a flutter, why not try another game of chance, where at least the money you bet is still yours even if you don’t win?

We’re talking about Premium Bonds. In this era of National Lottery Live, they may seem a little passe with Ernie - the Electronic Random Number Indicator Equipment used to select winning bonds - not sounding quite the match for the exotically named Topaz, Opal and Amethyst, just three of the 12 lottery ball machines.

But passe or not, Ernie has just notched up half a century of slogging through numbers for more than 110 million tax-free prizes worth more than pound;7 billion. And about 23 million people have money invested in Premium Bonds, according to National Savings and Investments (NSI). In the past 10 years alone, there has been a seven-fold increase in the number of Bonds in the draw.

So what should you know about Premium Bonds? Firstly, that they are a kind of savings account with the NSI that is backed by the Treasury.

Unlike a savings account, the money you invest buys bonds that are entered into a monthly prize draw in which you stand to “win” interest of between pound;50 and pound;1 million tax-free.

Each month’s prize fund is the equivalent of one month’s interest on the total value of eligible Bonds, at the current rate of 3.80 per cent.

Premium Bonds can be bought online at www.nsandi.com, in Post Offices or by telephone (0500 007 007). The minimum outlay on Bonds is pound;100 and the maximum pound;30,000.

But what are your chances of winning? Very slim, is the short answer to that, according to Martin Lewis of moneysavingexpert.com whose team has studied the numbers very closely.

He says that each bond’s chance of winning a million is 18 billion to one. Of the pound;36 billion in each monthly draw, there will be 1.7 million prizes given out of between pound;50 and pound;1 million each.

More than 1.4 million of these are pound;50 prizes, 260,000 are pound;100 and the remaining 10,000 range from pound;500 upwards. There are only two pound;1 million prizes.

Which is not that much money - and not that many prizewinners. Martin puts it more starkly: “Your chance of winning the jackpot per pound;1 spent on the lottery is one in 14 million, far out-stripping the one in 18 billion chance of becoming a millionaire through the Premium Bond draw.”

It is worth remembering that money spent on Premium Bonds is still yours and can be withdrawn at any time. Money spent on the National Lottery has gone forever, whatever the odds.

Given that all winnings are tax-free, Premium Bonds can be a serious place to put savings if you are a higher rate taxpayer and have used up your cash Isa entitlement.

If you want to check out what the probability is of winning money with your Premium Bond investment, then try MoneySavingExpert’s Premium Bonds Calculator at www.moneysavingexpert.com. Here you will discover that if you invest just pound;100 in Premium Bonds, your chance of winning absolutely nothing in a year is 94.4 per cent. Your chance of a payout of pound;50 or more is 5.55 per cent.

Obviously, the more Bonds you buy, the greater your chance of winning - something, at least. But the greatest mistake, says Martin, is to think of Premium Bond prizes as “winnings” in the first place.

It is, after all, a huge savings account with Ernie at the helm. But unless you have spare cash to play with you would do better placing your money in a high-earning account paying more than 6 per cent interest.

If you already have Premium Bonds but haven’t checked up on them recently, it could be worth your while. Some pound;30 million of prizes are still waiting to be claimed. See www.nsandi.com to check if you are a winner. You could be a millionaire after all, and you just didn’t know it.