Defining tax codes
You can use Management Center to access tax codes and related settings. If there are multiple calculation codes applicable to same product or category, tax calculation returns the calculation code with the highest sequence (sequence is a numeric column in table calcode). To define priority when multiple calculation codes are qualified, you have to adjust the value of sequence column in the database table CALCODE.
Before you begin
Associate tax codes to categories
Before you begin
After setting up all tax rates and tax codes, last step would be to assign taxes to the products in the catalog. You can assign taxes to categories in catalog or catalog entries in the catalog for products and SKUs using dataload. Follow SalesTaxCode for more information on this.