Taxation by countryA sales tax is a tax on consumption and is normally a certain percentage that is added onto the price of goods or services that are purchased. Sales taxes in the United States are assessed by every state except Alaska, Delaware, Montana, New Hampshire and Oregon. Hawaii has a similar tax although it is charged to businesses instead of consumers. In some cases, sales taxes are also assessed at the county or municipal level. While there is no national sales tax in the United States, the most frequently proposed measure to institute one in Congress is the Fair Tax Act, which would replace most federal taxes with a national retail sales tax and monthly tax rebate to households of citizens and legal resident aliens.Sales tax is usually the responsibility of the merchant to collect and remand to the state, and stated separately (or implicitly added at the time of sale) to consumers. Usually only consumers are charged the tax; resellers are exempt if they do not make use of the goods. In some jurisdictions, a reseller's certificate is required to make use of this privilege. This is in contrast to a Value Added Tax (VAT), where resellers are also taxed (resellers may then claim the VAT paid on their purchases from the applicable authority). States which have exemptions for specific types of organizations (such as schools), may also require a certificate. A sales tax audit is the examination of a company’s financial documents by the state’s tax agency to verify if they have collected the correct amount of sales tax from their customers.The Constitution of the United States limits the power of the states to subjects within their jurisdiction. Jurisdiction over interstate commerce is reserved to the federal government. Nevertheless, a resident of a state with a sales tax who purchases goods from a place with no sales tax (or at a lower rate) might be subject to pay a "use tax" (often at the same rate as the state sales tax) for non-exempt purchases (see also tax-free shopping).