Tennessee, California, Washington, Oklahoma and Louisiana have the highest combined state and average local sales tax rates, according to updated information released by the nonpartisan Tax Foundation today. On the other end of the scale, Delaware, Montana, New Hampshire and Oregon all have the lowest combined rates of 0 percent.

"Sales taxes are at the same time transparent and opaque," said Tax Foundation Staff Economist Kail Padgitt. "Taxpayers can easily see sales tax rates by looking at the receipt for any purchase, but depending on the locality in a specific state, there may be a variety of local option sales taxes in addition to the state rate."

The states with the highest combined state and local rates are Tennessee, at 9.41 percent; California, at 9.06 percent; and Washington, at 8.78 percent.