Invoice

An invoice is a commercial document that itemizes and records a transaction between a buyer and a seller. If goods or services were purchased on credit, the invoice usually specifies the terms of the deal and provides information on the available methods of payment. Types of invoices may include a receipt, a bill of sale, debit note, or sales invoice.An invoice must state it is an invoice on the face of the bill. It typically has a unique identifier called the invoice number that is useful for internal and external reference. An invoice typically contains contact information for the seller or service provider in case there is an error relating to the billing.