Sales tax is relatively straightforward for brick-and-mortar retail stores. A shopper goes into a store, buys something, and pays the sales tax for the state, county, and city where the store is located. It’s simple.
In contrast, online retailers must collect and pass through sales tax for every state, county, or city where the retailer has legal nexus. In theory, this tax collection burden could be an expensive and significant challenge that might have a large online retailer collecting taxes for hundreds or even thousands of jurisdictions.