Zero Dollar Invoices(Expense Reports)

We are on R12.1.3 and we use IExpenses for expense reports. We have both credit card and non credit card transactions in our system. When we interface credit card expense reports into AP, it normally creates $0 invoices in AP. Our AP does not use $0 payment process to mark $0 invoices as paid. We are trying in implement $0 payment process to mark $0 invoices(expense reports) but business is not ready to implement this process. They have asked us to find out the  risks if we don't implement the $0 payment process.

I have tried to find out but i am not able to find out any risks. So please help me find out the risks if we do not implement the $0 payment process.Check the attachment for $0 invoice status.