Entering a Purchase Order (PO) Number on an Order Paige Freeman May 17, 2023 14:48 Updated A purchase order (PO) number is an alphanumeric code assigned to an order placed by a vendor. This is considered a legal contract for payment. Entering a PO Number for a Proforma order will automatically change the Line Status to "Active" and the order will be picked up for shipping. The steps below assume that you are not currently viewing the order in which you want to enter a purchase order number. If you are currently viewing the order in which you want to enter a purchase order number, skip to step 2. To enter a purchase order (PO) number on an order: From the Orders Central page, search for the appropriate order. For more information, please see Searching for an Existing Order. From the order summary page, click the pencil icon in the top, right corner. Expand the Master Order Information section and enter the PO No.