Sales taxes can be applied to tangible goods like food (in some states), clothing, cars, furniture, household items, and other goods. By comparison, the sales tax does not generally apply to landscaping services, attorney fees, private school tuition, stocks and bonds, real estate investments, and other purchases more typically made by higher-income families.

A seller has to charge sales tax if it has 'nexus' where it is located. Nexus, or physical presence, is established if a business maintains a temporary or permanent presence of people (employees, service people or independent sales/service agents) or property (inventory, offices, warehouses) in a given locality. There is no over-arching definition of nexus, so each taxing locality may define it differently - and many do, leading to endless problems for businesses which have operations in multiple states.

All the products are subject to sales tax, and states offer different exemptions for this. Food, clothing, pharmaceutical products, purchases for agricultural are commonly excluded. The rates of sales tax may also vary within a state for different types of business.