I'm not going to comment on other states (and those of you not in the US, sales taxes are levied only by state and local governments; there is no federal sales tax), but in North Carolina (NC G.S. 105-164.4):

A privilege tax is imposed on a retailer at the following percentage rates of the retailer's net taxable sales or gross receipts, as appropriate. The general rate of tax is four and one-half percent (4 1/2%).

That's only the state tax. I assume that the local tax (which is collected at the same time and, in fact, remitted to the same state government agency where it's redistributed to local agencies) is similarly worded, but I could be wrong.