Why is the limit on Premium Bonds set at £30,000? The NS&I's job is to raise funds in a cost-effective way, compared with raising them from issuing Government bonds, which is the main way the Government raises money. At the moment it can raise cash through these bonds, known as gilts, relatively cheaply. This gives the Government almost no incentive to raise money through NS&I. The organisation's latest statement, released last month, indicated that the Government intended to raise no money at all through NS&I this year. The statement said that if it was to take in more money, it would have to reduce its interest rates "to levels significantly below those currently offered" in order still to offer value for money to the Treasury. Because of this, NS&I has little incentive to offer either attractive savings rates or to increase the amount that savers can put into premium bonds. It also said that it would be unable to offer its other most popular products, Index-linked savings certificates, to the market this year. The maximum investment in the bonds has been £30,000 since NS&I last increased it, by £10,000, in 2003. More than 20 million people are believed to own Premium Bonds, and every bond has a 24,000-to-one chance of winning a prize. However, you would have to have exactly average luck to earn the equivalent of 1.5pc interest on your bonds, meaning that your actual return is uncertain. Every month, one person will scoop the £1 million prize, while five people will win £100,000. The most commonly distributed prize is £25, and 1.8m people will collect this prize every month. Despite the bonds" continuing popularity, the chance of winning is far slimmer than it used to be. Back in 1994, the odds were just 11,000 to one, giving people more than twice the chance of winning. One reason for the bonds" popularity is that all prizes are tax-free. And each £1 bond has an equal chance of winning, regardless of when or where it was bought. Despite the scheme being referred to as a "squalid raffle" by the opposition, when it was introduced in 1956 by Harold Macmillan, Premium Bonds seem likely to remain popular for some time to come. Email your question to money@telegraph.co.uk