In international trading, the commercial invoice is a form used by customs to declare the goods or merchandize to be shipped. The document contains the name of the parties involved in the transaction including their contact information, the goods being shipped and the cost of the merchandize.
Customs use the commercial invoice as its primary document, so there are specific details that customs require in the invoice like the country of origin or manufacture and compliance with a harmonized system so that tariffs can be easily calculated.