Product: QBW Description: ID of the Line Item. Product: QBO Description: ID of the Line Item.[br /]QBO considers a request as an update operation for a line item, if you provide an ID that is greater than zero and the ID exists in QBO.[br /]QBO considers a request as an create operation for a line item in any of the following conditions: No ID provided, ID provided is less than or equal to zero, ID provided is greater than zero and does not exist in QuickBooks.[br /]Required for updating existing lines.[br /]Not supported for BillPayment, Estimate, Invoice, or Payment. Required: QBO

public string Id { get; set; }