A computer-implemented method comprising receiving a set of rules that define assigning tax codes for a first entity based on a plurality of parameters; receiving invoice data that defines an invoice directed to the first entity; automatically determining a commodity type applicable to the invoice data by digitally cross-referencing line items in the invoice data representing goods or services to community transaction data, the community transaction data comprising a plurality of different line item data for different invoices of other entities different from and unrelated to the first entity; automatically assigning tax codes to the invoice data based on the commodity type and the set of rules; and causing to display the commodity type and the tax codes in a graphical user interface.