Get the tax basics from Vertex: Defining Sales Tax, Sellers Use Tax, and Consumer Use Tax.
Sales tax is a transaction tax, calculated as a percentage of the sales price of taxable goods and certain taxable services. Sales tax is usually imposed on the purchaser (consumer). However, some sales taxes are imposed on the seller, sometimes called a “transaction privilege tax”. However, in either case, the tax is typically collected by the seller from the purchaser and remitted to the state by the seller. The tax is usually imposed on sales of tangible personal property and selected enumerated services. If a consumer of a state makes a taxable purchase within his/her own state, the full sales tax is paid at the time of the transaction.
Sellers use tax is the same as a sales tax. It is a transaction tax, calculated as a percentage of the sales price of goods and certain services. However, the key difference is that the sellers use tax is imposed on vendors located outside of the state, but are registered to collect tax in the state. Sometimes this tax is called a retailer's use tax or a vendor's use tax. Also, sellers use tax sometimes is not filed on a sales tax return. It is filed on a separate return called a sellers use tax return, vendors use tax return, or retailers use tax return. The sellers use tax rate is the same as the sales tax rate, which may include local sellers use tax.
Consumer use tax (sometimes referred to as a compensating use tax) is complementary to the sales tax. It is a type of “excise tax” imposed by state and local governments, calculated as a percentage of the sales price of goods and certain services; but paid as a use tax. Typically, consumer use tax is imposed on transactions that are subject to sales tax, but tax was not charged. Usually, this occurs when items are purchased out-of-state, ordered through the mail, over the Internet, or by phone from another state. It is imposed on the use, storage, or consumption of tangible personal property in the state. The use tax often applies when a company makes a purchase from an out-of-state seller that is not required to collect sales tax in the purchaser’s state.
Retailers are not usually required to collect sales tax on taxable purchases from consumers in states where the retailer does not have some connection to the state (known as "nexus"). This connection is created by retailers if they have a physical presence, make regular deliveries with their own vehicles into the state, have sales representatives located in the state, economic nexus, affiliate nexus, click-through nexus or marketplace nexus. The use tax burden falls on the consumer to calculate and remit the tax to his or her state government. Therefore, if the seller does not collect the tax from the purchaser and the transaction is taxable, the purchaser is responsible for remitting the use tax to the state.
Consumer use taxes are imposed by state and local governments for two reasons — to prevent someone from evading a sales tax by buying goods or taxable services from a non-taxing state and shipping them into the state that imposes the sales tax. The use tax protects retailers located in the state or municipality because it removes the incentive for consumers to shop outside that locality in order to avoid paying the sales tax. The use tax rate is the same as the sales tax rate, which includes state and may include local sales taxes. A taxpayer who does not pay use tax may be subject to interest and penalties.