I wouldn't worry too much, I've... in desperation put a hand written address into the ebay satchell plastic cover, taken it to the PO and put stamps on it... It got there just fine. Sometimes click and send just doesn't work in time. I learnt that I should set up my labels at least 2 hours before I need to leave for the PO. Then if there is a problem I have time to ring Click and send and get it sorted. They are very very helpful, if you are having trouble with your labels, ring them, they will most certainly try to help if they can.