Microsoft dynamics NAV 2016 allows you to capture and store invoices and credit memos as incoming documents and use them to create corresponding purchase documents or journal lines. As an alternative to e-mailing as file attachments, you can send and receive documents electronically. By electronic document, we mean a standard-compliant file representing a business document, such as an invoice from a vendor that you can receive and convert to a purchase invoice in Microsoft Dynamics NAV. The exchange of electronic documents between two trading partners is performed by an external provider of document exchange services.