As of February 2015, the Sales Tax Institute and the Sales Tax Clearinghouse both offer charts of sales tax rates by state on their websites. The Sales Tax Institute separates local taxes from the base state tax, and the Sales Tax Clearinghouse offers the rates separately and together.
The Sales Tax Institute offers a table listing sales and local taxes by state, including information about exceptions and conditions that may apply. Some of these exceptions include sales and deliveries to Indian reservations, importations for resale and tax caps on tangible personal property. The chart also supplies information about the applicability of local rates to use tax.
The Sales Tax Clearinghouse provides a chart of each state's base sales tax rate and its combined rate after application of the average local taxes. It also offers a map color-coded to show the average combined tax rate in each state.
As of February 2015, California has the highest sales tax rate. After combining the base sales tax and the state-wide county sales tax, California's rate is 7.5 percent. Oregon, Montana, Alaska, Delaware and New Hampshire do not have state sales taxes. Washington, Arkansas, Tennessee and Louisiana have the highest rates after combining the base state rate and the average local rate.