Electronic data interchange (EDI) is the computer-to-computer exchange of business documents in a standard format. These are agreed-upon data layouts created with the cooperation of the American National Standards Institute (ANSI). Financial EDI (FEDI) is the use of EDI to communicate the financial information related to payments and collections, as well as the instructions to effect a funds transfer between the parties. Essentially, it is EFT plus EDI; FEDI is what the nation's banking system uses to move money.
Over the last 10 years, the Federation of Tax Administrators and the ANSI group have together done a significant amount of tax data format standards development, primarily the creation of tax-specific document exchange standards and in addition recommendations on uniform implementation of administrative issues (like definitions of timely submission and the like) relating to electronic filing and payment.
Use of ANSI EDI/EFT standards for E-commerce by a government agency provides it with one suite of data formats for use in many of its EC programs. All 47 states with electronic tax collection programs employ the banking systems' FEDI capability. Approximately a dozen states also accept standard EDI data for the submission of electronic tax return data, particularly for motor fuel, sales and use, and employer withholding tax.
See Trends in State Electronic Commerce on this web site for indicative information on states' EDI programs.