bang it in a savings account, or you could always buy some premium bonds? Chance there of winning more money at no risk to your investment (only loss being getting no interest on the lump sum building over time), plus you have quick access to your money if you want to cash the bond in. If you don't need the money now, fair enough, but you might in a few years. What if your sister wants to go to college or university or whatever, you could help with fees then? sorry about your nan mate.