Marketplace Fairness Act - Expresses the sense of Congress that states should be able to enforce their existing sales and use tax laws and to treat similar sales transactions equally, without regard to the manner in which the sale is transacted, and to collect, or decide not to collect, taxes that are owed under state law.
Authorizes each member state under the Streamlined Sales and Use Tax Agreement (the multistate agreement for the administration and collection of sales and use taxes adopted on November 12, 2002) to require all sellers not qualifying for a small-seller exception (sellers with annual gross receipts in total U.S. remote sales of less than $500,000) to collect and remit sales and use taxes with respect to remote sales under provisions of the Agreement. Defines "remote sale" as a sale of goods or services attributed to a state with respect to which a seller does not have adequate physical presence to establish a nexus with the state.
Allows a state that is not a member state under the Agreement to require sellers to collect and remit sales and use taxes with respect to remote sales sourced to such state if the state adopts and implements certain minimum simplification requirements, including: (1) providing a single state agency to administer all sales and use taxes, (2) establishing a uniform sales and use tax base, (3) relieving remote sellers from liability to the state or a locality for collection of the incorrect amount of sales or use tax based on information provided by the state, and (4) providing remote sellers 30 days' notice of a tax rate change by any locality in the state.