However, a study by Empiris LLC chairman Jeffrey Eisenach and George Mason University law professor Robert Litan said the results of the University of Tennessee study were inflated.
It estimated West Virginia missed out on about $29.9 million in online sales taxes in 2012.
Whether the true figure is $29.9 million, $50.6 million, or somewhere in between, the new state law will capture only a fraction.
Tax Department spokesman Danny Forinash said the state couldn't name specific retailers that would be affected by the new law because of confidentiality requirements.
The law is expected to affect the Internet's largest retailer, Amazon.com, because it has a customer service center in Huntington.
An Amazon spokesperson did not respond to a request for comment.
Muchow said the change isn't expected to apply to very many companies.
"There's at least a handful or two that could be affected," he said.
Congress is still debating whether to give states the ability to directly collect sales taxes from online sales. The U.S. Senate has passed a bill to allow for collections, though it is unclear whether it will pass the House of Representatives.
Until Congress acts, Muchow said the new state law would slightly increase the limit of the state's reach into Internet sales.
"This is just the little bit extra we think we can get," he said.
Contact writer Jared Hunt at busin...@dailymail.com or 304-348-4836.
Other Business HeadlinesFiesta china maker sues over knockoffs