I will put my ads on to. They could just not come back. I will add to the contract a late fee, but $5/day I think is too low. I charge $30/day late fee. I would also include in the contract that vacation days payment must be done 2 weeks in advance (if you get paid bi-weekly) or a month in advance (if you get paid monthly). That way if they don't show up with the whole amount in advance (regular fee plus vacation days) just do not let the kid in. The money will appear that way.