A parse/build engine that can handle multi-format financial messages. The engine converts the different format messages into a common format, and the common format message is then processed by the business service application. A parser examines the message and determines an appropriate schema for the particular format of message received. The schema is a data structure in a schema registry that includes a grammar structure for the received format as well as pointers to handlers for converting the different fields of the message into the internal message format using the grammar structure (the "grammar" can include field sequence, field type, length, character encoding, optional and required fields, etc.). The handlers are individually compiled. As formats change, new formats or changes to old formats can be dynamically added to the parse/build engine by loading new schema and handlers.