[Ndptbudd]

Premium bonds are haram as the above links will show because the payouts are based on interest. I did seriously consider getting them but as interest is a major sin, I did not want any of the goods i own to have come from a haram source. I have actually invested (a very small) amount of money in stocks and shares through an 'ISA'. The risk is higher but the potential monetary rewards are greater and of course, if you invest in the right companies, it is halal. However I have read certain opinions that stocks are haram - so there is not ijma on this!
Also bear in mind a lot of companies though they do not look haram actually engage in a lot of bad things - such as dealing in interest (banks) or having very high loan levels (a lot of retailers are like this!) So be careful. You can also reduce your risk levels through 'sharia compliant' mutual funds - these create a certain list of factors and do not invest in those companies - the risk is less on these mutual funds - of course that means the potential reward or loss is less