Tigwig, you know it would be wrong not to declare this income or you wouldn't be asking. Not paying your tax is like not standing your round; possible, but likely to make you unpopular. What you really want to know is, will he get caught? Who knows? But the consequences of getting caught are not worth the risk. It's certainly possible the revenue will want to know about the blank period, even if its only to check on the national insurance record. And don't discount the possibility that someone will shop him. Seems to me the worry and the guilt aren't worth it. Anyway, the tax bill on �1000 isn't going to be �250; it would be �200 even if there were no expenses to claim - and I bet there would be, Bednobs makes a good point about the future, too.