Levy imposed on the sale of goods and services.
A sales tax on the manufacture, purchase, sale, or consumption of a specific commodity is known as an excise tax. Though excise taxes have been used since ancient times, the general sales tax is a comparatively recent innovation. Sales taxes are ad valorem taxes, imposed "according to the value" (i.e., monetary value) of the taxable commodity. They are classified according to the levels of business activity at which they are imposed
production, wholesale, or retail. They account for significant portions of the revenue of most U.S. states and Canadian provinces. A variation of the sales tax, the regressive tax , essential goods such as food, clothing, or drugs are sometimes exempted or taxed at a lower level. See also income tax ;{{link=progressive tax"> progressive tax .