Open Financial Exchange (OFX) is a unified specification for the electronic exchange of financial data between financial institutions, businesses, and consumers via the internet. Developed in the late 1990s by Microsoft, Intuit, and CheckFree, it serves as a standardized format for importing and exporting financial information such as bank statements, investment portfolios, and credit card transactions. Unlike older formats like QIF, which were often proprietary and prone to data inconsistencies, OFX uses an SGML-based (and later XML-based) structure that ensures high levels of interoperability between different accounting software packages and banking platforms. It is widely supported by major financial institutions globally, allowing users to download their transaction history directly into personal finance management software. The format is designed to be secure, extensible, and capable of handling complex financial data, including account balances, transaction details, and even bill payment instructions, making it the industry standard for automated financial data integration.