After the Arizona Department of Revenue retroactively assessed an online auto parts retailer $11 million in sales tax, the company is asking the state Supreme Court to take up the case. RockAuto, based in Wisconsin, has not paid state sales tax since its founding in 1999 because it does not have a physical presence in the state, which was previously a requirement for taxation under state tax laws. After being alerted by a Gilbert and Town of Gilbert taxpayer, ADOR conducted an audit of the company and told the retailer it must pay the taxes and penalties accrued between 2013 and 2019. The state tax court originally sided with RockAuto, but the Arizona Court of Appeals overturned that decision earlier this year. According to the appeals court ruling, RockAuto uses six Arizona distributors that occasionally ship products to customers in Arizona. Those distributors are required to use RockAuto packaging materials, and RockAuto employees made business trips to the state during the period from 2013 to 2019. The court said those criteria were enough to prove a physical presence in the state, even though the company has no property or employees in Arizona. RockAuto has since severed ties with its Arizona distributors and is considering stopping sales in the state over concerns about more taxes that could be imposed, the CEO told our reporter. Local attorneys James Busby and Paul Eckstein are representing RockAuto in its appeal to the Arizona Supreme Court, saying ADOR’s actions could open the door to retroactive tax charges on other out-of-state companies. “We really hope the Arizona Supreme Court recognizes the importance of this case, and not just to RockAuto, because it has a chilling effect on businesses across the state,” Busby said.