Interchange file (Quickbooks for Windows)
IIF is a data file format used by Quickbooks for Windows. IIF stands for Intuit Interchange Format, and these files are used to export financial data. IIF files contain text-base, tab-delimited format similar to .TSV files. IIF files can be opened and read by most spreadsheet programs, such as Microsoft Access.
MIME: application/qbooks, application/qbookspro, text/iif
Learn more about .IIF files:
Search for .IIF-related questions on IT Knowledge Exchange.