Electronic Invoicing has attracted a lot of attention by being a cornerstone of the Digital Agenda for Europe, Europe´s 2020 Strategy. This agenda mandates a “think small first” principle in order to enable e-invoicing for companies of any size. The electronic invoice should be exchanged between the ERP systems of business partners. Traditional approaches based on electronic data interchange failed to attract SMEs. Due to the high costs, they only use e-invoicing if forced by their larger business partners. In this paper, we present an alternative approach that is based on native ERP integration of most common e-invoice scenarios. This approach was successfully implemented in a research project resulting in a university spin-off.