Reference
Sales tax, and who decided it.

Everyone quotes their state's sales tax rate. In much of the country that number is only half the story, because the county adds its own on top — and in a few states the county's half is the bigger one. Here is where each state sits.
A state's headline sales tax rate describes the whole charge only where local jurisdictions have no taxing authority. Elsewhere it is a floor, and the share delegated to counties and municipalities ranges from nothing to everything. States are grouped below by that share, measured at each state's representative county.
51 states
The state sets all of it
No county or city may add anything. The rate quoted for the state is the rate charged at every address in it — which is not true of most of the country.
Your county sets most of it
The local add-on is larger than the state rate itself. Rank these states on their state rate and you are ranking the smaller half of their tax.
The two share it
Both layers are substantial, so the combined rate depends on where the sale happens and the state rate is a floor rather than the figure.
- ArizonaCombined about 8.54%
- North CarolinaCombined about 7.1%
- WashingtonCombined about 9.57%
- ArkansasCombined about 9.48%
- South DakotaCombined about 6.11%
- IllinoisCombined about 8.98%
- North DakotaCombined about 7.09%
- CaliforniaCombined about 10.25%
- TennesseeCombined about 9.61%
- WyomingCombined about 5.39%
- KansasCombined about 8.71%
- TexasCombined about 8.25%
- NebraskaCombined about 6.98%
- OhioCombined about 7.29%
- South CarolinaCombined about 7.49%
- UtahCombined about 7.42%
- NevadaCombined about 8.24%
- MinnesotaCombined about 8.13%
Local government adds a sliver
Counties may add, but narrowly. The state rate is a reliable stand-in for what a purchase actually pays anywhere in these states.
States with no general sales tax
Nothing is delegated because nothing is levied — no state rate, and no local one either. See each state's tax guide for what it collects instead. Alaska is not on this list: its state rate is zero, but its boroughs levy real sales tax and it has a page of its own.