Invoice Verification is a process which confirms in SAP that an invoice has been received by the department. Goods receipt will have to have been entered on SAP prior to invoice verification unless that process has been by-passed at the raising of the purchase order.
This guide explains how to verify an invoice against a purchase order on SAP. A purchase order should be raised before an invoice can be verified
Logistics→ Materials Management→ Logistics Invoice Verification→Document Entry→MIRO – Enter Invoice