Marketplace Fairness Act of 2013 - (Sec. 2) Authorizes each member state under the Streamlined Sales and Use Tax Agreement (the multi-state agreement for the administration and collection of sales and use taxes, adopted on November 12, 2002) to require all sellers not qualifying for the small-seller exception (applicable to remote sellers with annual gross receipts in total U.S. remote sales not exceeding $1 million in the preceding calendar year) to collect and remit sales and use taxes for remote sales under the provisions of the Agreement, but only if such Agreement complies with the minimum simplification requirements relating to the administration of such taxes, audits, and streamlined filing set forth by this Act. Authorizes any such state to exercise its authority under this Act beginning 180 days after publication of its intent to exercise such authority, but not earlier than the first day of the calendar quarter that is at least 180 days after the enactment of this Act.
Allows a state that does not participate in the Streamlined Sales and Use Tax Agreement (non-member state) to collect and remit sales taxes if such state adopts and implements the minimum simplification requirements of this Act. Provides that such taxing authority shall commence no sooner than six months after such state:
(Sec. 3) Declares that nothing in this Act shall be construed to:
(Sec. 4) Sets forth definitions used in this Act, including defining "remote sale" to mean the sale of goods or services into a state in which the seller would not legally be required to pay, collect, or remit state or local sales and use taxes unless provided by this Act. Sets forth rules for determining the source of a remote sale (i.e., the location where the product or service sold is received by the purchaser).
(Sec. 6) Declares that nothing in this Act shall be construed to preempt or limit any power exercised or to be exercised by a state or local jurisdiction or under federal law.