Credit Control is used to keep the extended credit to the debtor in control so that the debtor does not convert into a bad debt.
You can set credit control for every debtor based on the max overdue days and max outstanding amount. This can be done using Edit Contact option.
This feature, when enabled, sends you an alert if a new invoice is raised for the debtor whose invoice is overdue by more days than the set max overdue day or outstanding amount is more than the max outstanding limit set.