I am a subcontractor and I require 10% of invoice due to schedule the project. I've run into times where the customer will cancel within a few hours of the scheduled job. I have already purchased materials and staffed employees for the project. I'd like to be fair with my clients in this situation, but also can't keep costing the company money by this. Are we able to state the 10% down payment is nonrefundable? But remaining balance is fully refundable, minus costs already incurred if notified within 72 hours of scheduled project date?