Purchase order balance tracking is a feature that enables you to report and track the balance of your POs against your invoiced amounts. When adding/editing your PO details, you have the option to enable balance tracking and input amounts for your PO line items. Whenever an invoice is generated and matched with your PO, the balance of the corresponding line item as well as your PO will be reduced. If you have configured contacts on your PO, they will receive email notifications when the PO line item balance falls below a 75% threshold.