A pre-invoice, also known as a pre-payment invoice, is an estimate of billed goods and services sent to a customer before delivery. Pre-invoicing is a way for a vendor to communicate charges upfront to a buyer. This protects against confusion later on and allows the buyer to understand pricing before finalizing a purchase.
Many would-be customers will ask a vendor to submit a pre-invoice to help the customer determine whether he wants to make a purchase. The pre-invoice documents the items and quantities ordered, the unit prices, the shipping and handling charges, the delivery dates and the payment terms. This way a potential customer can compare one vendor's offer to another. A pre-invoice can also serve as an estimate of costs so a potential customer can decide whether a purchase fits into its budget. Unlike a final invoice, which is distributed after an order is made and delivered, a pre-invoice isn't a request for payment.