When invoice data are received in an EDP system, an accounts payable clerk determines the account numbers to be charged and enters them at a terminal. If purchase orders include these account numbers, the system performs this step automatically by retrieving the account numbers from the computer file of purchase orders. The data are compared to the purchase order and receiving report. The common matching criterion on all documents is the purchase order number. Quantities, dollar amounts, due dates, terms, and unit prices are compared and reconciled. When in agreement, the cost data are entered into the accounts payable file (and listings in journal form are produced, as needed). Alternatively, payment can be made immediately by means of EDI or a computer-generated check. The receiving date are posted to materials subsidiary records. These postings and those for materials issuances are processed electronically to eliminate manual posting.