Economic nexus imposes a sales and use tax collection obligation on remote sellers based only on their economic activity in a state. Nearly 30 states have adopted economic nexus since the Supreme Court of the United States ruled physical presence in a state is no longer the sole requisite for sales tax collection (South Dakota v. Wayfair, Inc., June 21, 2018), and all provide an exception for small sellers. The problem is, these exceptions are not all the same.