Two years ago, on June 21, 2018, the Supreme Court of the United States ruled in favor of the state in South Dakota v. Wayfair, Inc. It was a pivotal decision for sales tax, states, and businesses.

Here’s a recap: The Wayfair decision overruled a long-standing physical presence rule that, according to the majority, treated “economically identical actors differently for arbitrary reasons.” For example, a business with just a few items of inventory in a small warehouse in a state was obligated to collect and remit that state’s sales tax on all its sales, while an internet seller with a “pervasive” presence couldn’t be required to collect tax on similar sales.