File with a .OFX extension contains financial data – transactions, declarations, data on finances stored in an open format, designed for purpose of exchange of such data between different entities. It is used by sellers, consumers and financial systems, for example – as a message format containing bank statements or credit card statements.

OFX file format is based on the SGLM file format and it was standardized in the year 1997, by Intuit, Microsoft and CheckFree. Within the Open Financial Exchange Consortium it is used as a standard financial data format, replacing older, specific to Microsoft Money – OFC (Open Financial Connectivity) file format.