Economic nexus

Since the Supreme Court's 2018 Wayfair decision, every state with a sales tax sets a sales threshold above which a seller elsewhere has to collect its tax. Most use $100,000 a year. California and Texas use $500,000, and New York $500,000 plus more than 100 sales. Below the threshold, with no presence in the state, a seller owes it nothing. Marketplaces collect on their own sales, but in many states those sales still count toward the threshold.