The explosive increase in e-commerce has come at great cost to state tax revenues; one estimate is a cost of $12 billion/year. This cost is primarily a result of the U.S. Supreme Court interpreting the dormant commerce clause to require that a retailer must have a physical presence in a state before the state may require the retailer to collect sales tax. As a result of this ruling, states do not generally require companies like Amazon (which have intentionally limited their physical presence to a handful of states) to collect their sales tax in the same way as a merchant physically located in the state must collect state sales taxes. This panel will look critically at the many recent developments in the states’ efforts to require retailers to collect sales taxes on internet sales or, alternatively, to enforce state consumers’ obligation to report their internet purchases and pay the taxes owed on those purchases. The panel will assess the different approaches taken by the states from various perspectives, including whether these approaches are consistent with current law, whether Congress should intervene (and, if so, how), and whether any of these approaches are sensible as a matter of policy.