Oracle Purchasing offers 2, 3, and 4 way invoice matching methods. 2 way matching matches invoices to purchase orders, 3 way adds receiving information, and 4 way adds inspection information. The level of matching can be set at different levels to override defaults. 2 way matching simply checks invoice quantities and amounts against the purchase order, while 3 and 4 way matching add additional validation of receiving and inspection records. If tolerances are not met, an invoice hold is placed until resolved.