A clerical error caught by the Arizona Department of Revenue led to an incorrect tax rate being applied to this year’s primary property tax levy. Pinal County officials say they will issue corrected 2025 property tax bills and provide refunds to anyone who has already paid.

The issue, first identified Sept. 15, was the result of a math error in spreadsheets used by the Joint Legislative Budget and Finance Office when compiling rate sheets for approval. The error inadvertently changed the tax rate, affecting roughly 290,000 parcels across the county. So far, they’ve sent out 72,000 updated tax bills and owe refunds to 7,000 residents who paid their taxes early.

In an interview today, Treasurer Mike McCord told InMaricopa his office moved quickly once the issue was identified.

“When we found out about it, the first question was, can our IT staff fix it? Once they found the fix, we planned the PSA,” he said. The county released a short video explaining the issue yesterday. “We’re not trying to hide anything from anybody. It’s important that we have government with transparency.”

Treasury employees worked nights, weekends

McCord explained that Pinal County’s tax software, which was created in-house about 20 years ago, automatically processes rate data provided by the Finance Department.

“When the rate changed inadvertently, it got missed,” he said. “We assume the numbers are correct, and they get entered into the tax collection software. That’s how the bills are generated.”

The mistake occurred in a formula used in the finance department’s spreadsheets, which calculate tax rates across five to 12 taxing authorities in each area code.

“It’s never happened before,” McCord said. “Our IT department had to go into the old system and literally write new code to fix it. The programmers figured out how to make the fix, and anything going forward with those patches will work.”

To prevent a repeat, the county is changing its processes.

McCord explained the plan going forward: “It’s not only going to [Pinal] County Finance, it will also go to the Treasurer’s Office. That letter will then get sent to us so we can have two sets of eyes on it.”

The county began reprocessing bills immediately, working nights and weekends to avoid slowing down daytime operations.

“We can do a lot when no one is in the system,” added McCord.

Of those 72,000 corrections, 65,000 were done over the weekends.

Super: ‘People make mistakes… It happens’

County Supervisor Rich Vitiello (R-Maricopa) said the error, while unfortunate, was simply a clerical mistake.

“They’re adding another layer of checks and balances so this doesn’t happen again,” he told InMaricopa. “People make mistakes. I don’t like to use the other word, but it happens.”

McCord expects the corrections to be complete by the last week of November or Dec. 1.

Because the corrected rate is lower, property owners who already paid their taxes will automatically receive refunds. Those who haven’t paid should wait for their revised bill before they pay. McCord said the county is also coordinating with banks and mortgage companies for escrowed payments, roughly 30,000 parcels, which must be processed by Oct. 31.

“They have them escrowed into their mortgages,” he said. “We send that to the banking institutions, and those are the priorities.”

McCord also announced a grace period to ensure taxpayers aren’t penalized for the delay.

“We’re giving a grace period. The tax bills won’t be late if you pay them later than the due date. That’s at my discretion,” he said. “The board of supervisors is aware. To build goodwill and make sure the citizenry is taken care of, we’re giving them that grace period. My goal is to not have anyone affected by this.”

County manager: ‘Our teams acted quickly’

McCord said the situation highlighted the importance of checks and collaboration across departments.

“When we sit around the table, we’ll have finance embedded so we’re all in the same room together,” he said. “You don’t know there’s a problem until something breaks. Now we know.”

He praised the county’s IT team for acting quickly and effectively.

“I’m not a tech guy, but I’ve got a great tech team,” he said. “They’re watching the system run. We’re one weekend in and have had great success getting these corrections done. I’m impressed with what we’ve accomplished.”

County Manager Leo Lew said the county’s response demonstrates accountability and transparency.

“The Arizona Department of Revenue caught the inconsistency, and our teams acted quickly and transparently to correct it,” Lew said.

McCord added, “We’ve been doing this for 20 years. It’s never happened before, and it won’t happen again.”