The documents generally required from Mauritanian importers include the commercial invoice, the bill of lading or certificate of origin, and the certificate of inspection given by the SGS, the private company that provides import and export certification.  The commercial invoice should contain the name and address of the buyer and seller, the place and date the invoice was prepared, the method of shipment, the quantity, description, and price of the goods, and delivery and payment terms.  Large payments are usually made by irrevocable and confirmed letters of credit or by direct bank transfer.  Cash payments are also frequently used for smaller purchases.  Importers require pre-shipment inspection and quality control.  The certificate of inspection should accompany imported goods.