You want more information on the rate file format so you can read the Avatax ISPI Rate files.
Avalara Rate files
- MS Access files have headers which describe what each column is for
- The csv files require a header file, attached here
- If you file has commas, use the tab called 'CSV File Layout'
- You can import your rate file into the above Excel file to view the file with the description of each heading.
- Microsoft's Knowledge Base has information on how to import CSV files into Excel.