A purchase order flip happens when a PO invoice is created digitally. Every line level of the purchase order is received electronically and the data is used to generate e-invoicing. The PO information is transferred in real-time through the system and ends up as an electronic invoice. The process starts when a customer files a PO online (generally through a supplier portal). This allows orders to be submitted into supplier accounts electronically. It is then assigned an invoice date and number and returned to the buyer.  The usage of automated tools is where the term "flip" was coined. The system is instantaneous. Not only does this expedite the invoicing process, it increases efficiency and leaves much less room for error.