Abstract: To avoid cost and errors associated with manual data re-entry, methods are provided for transferring data between different business systems (e.g., computer programs). After data for a purchase order is entered using a first purchase order generating program, a data file is prepared including the input data correlated with field identifiers identifying the individual information category of particular data elements. Field identifiers may typically be a sequence of numbers or merely a pre-selected sequence of the data fields. The data file is encoded into a 2-D image code which can be printed out with the purchase order. On decoding of the 2-D image code by a recipient, the data file is recovered. The field identifiers then enable identification of particular categories of information for mapping into the second business system, such as an order acceptance/invoice generating program.