By Corinne Murdock |

On Tuesday, the Arizona Supreme Court ruled that Pinal County’s transportation excise tax was unlawful. The ruling affects two 2017 voter-approved measures from the Pinal County Regional Transportation Authority (RTA) Pinal County Board of Supervisors. The two measures instituted a tax on purchases under $10,000, constituting a two-tiered retail transaction privilege tax (TPT) that would pay for infrastructure. 

The Arizona Supreme Court disagreed with the county’s assertion that the tax afforded a modified and variable rate in accordance with state law. 

“We therefore conclude that the two-tiered retail TPT structure in Proposition 417 is neither a ‘modified rate’ nor a ‘variable rate’ under § 42-6106(C). In this case, until the legislature ‘expressly delegates’ to counties the authority to implement this tiered-rate tax on specified businesses—an authority that is ‘strictly construed’ — Pinal County’s two tiered retail TPT structure as part of a transportation excise tax is unlawful and invalid,” wrote the court. 

The ruling marked the Goldwater Institute’s seventh Arizona Supreme Court ruling in their favor. The institute’s vice president of litigation, Timothy Sandefur, asserted that the ruling ensured clarity, ease, and lowered costs for businesses.

“The legislature intended state taxes to be uniform — not to allow each of the state’s 15 counties to set their own rules. To allow that would make Arizona inhospitable for business, because it would transform the state into a crazy quilt of different tax rules in each locality,” wrote Sandefur. “[I]t marks a victory for taxpayers not just in Pinal County but throughout Arizona. In tough economic times—with inflation and fuel costs rising—the last thing Arizona needs is for public officials to create more and more complicated tax rules that take more of people’s earnings away and drive away job-creating industry.”

Corinne Murdock is a reporter for AZ Free News. Follow her latest on Twitter, or email tips to corinne@azfreenews.com.