Proforma Invoice, Invoice, and Commercial Invoice are all related to the sale of goods or services, but they serve different purposes in the sales process. 1. Proforma Invoice: A Proforma Invoice is a preliminary bill of sale that is issued by a seller to a buyer before the actual shipment of goods or provision of services. It provides an estimate of the cost of goods or services, including taxes, duties, and other charges that may apply. A proforma invoice is often used in international trade t