https://www.theverge.com/2018/6/22/17493298/supreme-court-internet-sales-tax-congress-amazon-etsy-ebay

In the wake of yesterday’s Supreme Court ruling, e-commerce companies are understandably both concerned and uncertain of their future. The 5-4 verdict overruled a 1992 precedent set by the case Quill v. North Dakota that only addressed mail-order businesses at the time, but it became a powerful legal bedrock for the e-commerce industry. It let companies without a robust physical infrastructure thrive during and after the dot-com boom by exempting purchases from sales tax, so long as the seller did not have a physical operation in the state where the customer resided. Now, following the court’s decision, states can start charging sales tax on internet purchases even when a retailer has no physical presence in that state.

A number of retailers, from Amazon to Etsy to Overstock.com, may be impacted. It’s not necessarily because those corporations have been skirting sales tax collection, but some enable thousands of third-party sellers to do so, largely thanks to Quill v. North Dakota. In fact, Amazon, which last year started collecting sales tax in all 45 states that require it by law, may have a substantial amount of work to do to help its Amazon Marketplace sellers stay compliant. Yet we don’t know if that burden will fall primarily on Amazon or if it will be the responsibility of the sellers.