The US Supreme Court ruled that states may levy sales tax on online purchase(a) notwithstanding the lack of a physical presence in the state of purchase overruling the prior standard delineated in Quill Corp. North Dakota.   The ruling subjects on-line sellers to the tax liability in the state(s) where its products are sold.   
In South Dakota v. Wayfair, the Supreme Court ruled that a state may impose a sales tax on internet sales delivered to its residents even if the internet seller has no physical presence in the state rolling back prior precedence of Quill Corporation v. North Dakota and National Bellas Hess Inc. v. Illinois Department of Revenue. While the “economic presence test” utilized was found Constitutional, states remain free to craft their own threshold and legislation for the collection of tax. States are likely to utilize a same or similar structure to collect sales tax from internet sales within the state as implement by North Dakota with its economic presence test.

 

The opinion may be found here:  https://www.supremecourt.gov/opinions/17pdf/17-494_j4el.pdf