An IUC is just an interview where investigators try to get information concerning questions they have unanswered and to allow the other side to put across there side of the story. It goes from them to a decision maker and they are the ones that say court, admin+repay or simply to repay. FYI: normally anything below £4000 is normally a repay+admin charge and the reason for this is that they get the money back + cover the costs in getting it back which is a win win for them, in general it's the stubborn ones and the ones that have deliberately done it and then try to cover it up and make the investigators job harder that they are more