Electronic invoicing, or e-invoicing, like the name implies, is the electronic exchange of invoice documents between a supplier and the customer. Electronic invoicing goes beyond merely sending a PDF receipt to a customer via email. A true e-invoicing solution is an integrated solution where an electronic invoice is transmitted and received seamless between the supplier’s accounts receivable system and the customer’s accounts payable system. E-invoicing documents are typically exchanged in EDI or XML formats. (Source: E-Invoicing Basics)