Intuit Interchange Format, aka Intuit Interchange Format, is a text data format created in 2004.

The IIF file format, Intuit Interchange Format is a proprietary text file used by Intuit's Quickbooks software for importing and exporting lists and transactions. As of 2004, QuickBooks can also import data using the XML-based qbXML file exchange format. The MIME‑types associated with .iif files are application/qbooks, application/qbookspro, and text/iif.. Read more on Wikipedia...

• Intuit Interchange Format Wikipedia page
• Intuit Interchange Format first developed in Intuit Inc