With the new year, Amazon is charging sales on purchases in three more states - Indiana, Nevada, and Tennessee. Amazon agreed to begin collecting sales tax in the three states in 2014, bringing to 19 the states in which it automatically adds tax to purchases.
In 2016, South Carolina will join them, bringing the number up to an even 20. Amazon's warehouse expansions have given it a physical presence in more and more regions, speeding up deliveries but also opening it up to taxes.
Source:
http://www.sportsonesource.com/news/spor/spor_article.asp?section=9&Prod=1&id=49275
