Amazon Sellers Hit by Huge Back-Tax Bills Across the Country

Steve Jenson of Logan, Utah, thought he had a good business selling books through Amazon.com Inc.—then he got hit with a $200,000 tax bill from the state of Washington, alleging he had failed to collect and remit sales taxes from customers dating back to 2011.

It was a rude awakening for Jenson, who, like many other Amazon sellers, says he wasn’t even aware that he was supposed to collect the tax in the first place. He is now paying off the bill at a rate of $2,500 a month, which threatens his business.

“I can’t ...