3 Way match - Invoices are only valid if a valid purchase order exists. Invoices are checked on valid purchase orders (2 way match) or a valid purchase order and receipt (3 way match). Valid purchase orders are those: • Released, • Not blocked,/• Not locked,/• Not on hold./For 3 way match also those purchase orders having a receipt. Goods receipts cannot be processed if no valid purchase order exists and purchase orders should not be generated automatically for goods receipt.