Deleting Purchase Orders
You can delete purchase orders and individual details at any time until you post a receipt to the purchase order. After posting receipts to purchase orders, you cannot delete the purchase orders or any of their details. To cancel a purchase order detail after posting a receipt, you cancel the outstanding quantity.
To remove a completed purchase order from your system, you run Day End Processing if you do not keep history. If you keep transaction history, you remove completed purchase orders by using the Clear History form.