In this chapter, the author introduces people to the requirements of customs and reviews the documents used most frequently for exports both within Europe and the rest of the world. Each main phase of export has its own sort of documentation: transaction documents such as invoices, transportation documents such as the air waybill and the export documents required for customs and excise declaration. The purpose of the certificate of origin is to authenticate the country of origin of the goods. It may be required because of established treaty arrangements, varying duty rates, or preferential duty treatment dependent on the origin of the goods. The single administrative document declaration is made by the importer or exporter or their agent. It must be signed by the declarant, contain all the information necessary for customs and be accompanied by all the documents required for the customs procedure.