Billing is easily misunderstood. At first glance, billing seems to be a fairly simple process. And if everyone did what they are supposed to do when they are supposed to do it billing would be simple. But that seldom happens. The difficulty for the billing system is the amount of exception logic required. Short pays, over pays (yes, those do happen from time to time), late pays, and various combinations all result in a very complicated system. And that is before we layer in state regulatory requirements. Then there is the integration aspect of the billing system.