ofx

OFX, or Open Financial Exchange, is a standard for the electronic exchange of financial data between financial institutions and consumer software. It enables applications to retrieve account information such as balances, transactions, and holdings, and allows institutions to supply statements or transmit transactions to users’ software for reconciliation and analysis.

The specification originated in the late 1990s through collaboration among industry players including Intuit, CheckFree, and Microsoft. It was designed to provide a vendor-neutral format to simplify the transfer of financial data across different systems and software. Over time, OFX has been adopted by many banks and developers of personal finance tools, becoming a common mechanism for automated data import and export.

OFX defines a set of message types and data structures that cover sign-on, account information, bank statements, transaction histories, and investment data. The messages are typically delivered in a tag-based format, historically SGML-based and later implementations that use XML. Data is transmitted over secure channels, such as HTTPS, and requires appropriate authentication and authorization.

Versions of OFX have evolved since its inception, with OFX 1.x and OFX 2.x being the principal generations. OFX 2.x introduced XML-based representations in some implementations, while 1.x relied on SGML-style formatting. In practice, many banks and software programs support OFX to enable automated download of statements and transactions, though support is not universal, and some institutions favor proprietary APIs or other data-access methods.