There are no options to close purchase order after all line items have been receipted and all the associated transactions have been posted. The Purchase Order has a status of unprinted Purchase Order.
1. In Accounts Payable, select Records and select Purchase Orders and then click Open Purchase Order to open the Purchase Order in question 2. On the Purchase Order tab, change the status from Unprinted purchase order to Open purchase order 3. Save the purchase order 4. Close the purchase order