Property Values and Taxes Grow Across Illinois

The reasons for Illinois’ constant growth in taxable value and taxes are manifold and systemic. Property taxes have grown for over 30 straight years, showing no signs of stopping. The unending hunger of government bodies for funding is the prime motivator for increases across Illinois, and 2025 was a banner year for it. Budget shortfalls and increasing pensions are the main culprits. In Cook County, the infighting over funding nearly led to a government shutdown for the first time in the county’s history. In major urban areas, especially the collar counties, gentrification has been a huge influence on skyrocketing home values. The movement from cities to suburban and rural areas to avoid high costs has also led to increasing demand for housing.

Computer Error the First Domino to Fall in Chicago

While most of Cook County’s problems are decades old, the chaos of 2025 was started by a computer error. In an effort to modernize, the CCAO turned to the contractor Tyler Technologies. The initial idea was to build a system that connected the CCAO, Treasurer, and County Clerk, as each contributes to property tax assessment, collection, and disbursement. Instead of streamlining the system, this led to constant delays. This had a knock-on effect that lasted through all of 2025. The delay meant that tax bills were late, leading to funding and refunds also being delayed. With so many government agencies left in a holding pattern, things began to unravel.

Cook County Tax Bills Delayed from May to November

It took months for things to be somewhat sorted out, with the second installment of tax bills being sent out nearly six months later than usual. This caused immediate problems, as funding was again delayed, leading to school districts and other organizations taking out loans. The delay, of course, was worse for taxpayers. Not only were their bills months late, but many were much higher than expected. To top things off, the bills were due on December 15, which was both close to the holidays and with only three months separating it from the mailing of the first installment bill of 2026, as they are typically due in March. In order to compensate for this, the due date was eventually changed to April of 2026, giving taxpayers only one additional month.

Collapsing Office Values in the Loop Forced Higher Taxes on Homeowners

What truly made the delay in tax bills devastating was the huge increases contained within them for homeowners. Homeowners saw an average increase of 16%, the highest in the history of Illinois. Matters were made much worse for homeowners in the South and West Sides of Chicago, where the average bill doubled or more. West Garfield Park, for instance, experienced an average increase of 133%, with some homes spiking up to 600%. The brunt of the hikes was felt mostly by working people and minorities. While improvements to homes and gentrification were seen as the main driver for the increases, it was also revealed that the tax burden had been shifted to homeowners to make up for business shortfalls.

Offices in the Loop and retail spaces in the Magnificent Mile both saw huge decreases in their assessments and tax bills in 2025. According to the CCAO, this was because of vacancies for offices and retail stores, which led to the budget shortfall needing to be made up elsewhere. The CCAO, predictably, also tried to pass the buck, blaming property tax appeal verdicts by the Board of Review (BOR) for siding with businesses. The CCAO had previously bragged about homeowners being given a break by transferring the burden to businesses, so this could have been just a way to save face. Whatever the cause, this unexpected decline in business value was the main reason for both the huge average increases and the tax spikes.

Community Anger Forced Emergency Measures

This was truly the straw that broke the camel’s back. Since the 2023 reassessment, taxpayers in Cook County have been on edge, waiting to see their own devastating increases. Though each third of the city got beaten down by reassessment, the general increase of 2025 on such short notice fueled a fury in the taxpayers like never before. Tax bills were burned, angry meetings took place, and constant debates were had about fixing the problem.

The outrage forced some temporary changes in Cook County. This included reopening appeals for most of the county, a move never seen before. This window lasted from December 3 to December 12, allowing many homeowners to explore appeals for the first time. The treasurer was also forced to create a payment plan for taxpayers, a rarity in Cook County. This payment plan also saw interest rates cut in half, lowering the cost of repayment. While these may have been token gestures, they were also unprecedented, showing the power of the people of Illinois when they are moved to righteous anger.

Cook County Property Tax Sales Ruled Unconstitutional

The biggest consequence of not paying your property taxes is an eventual tax sale. This allows an investor to pay your taxes while also gaining a stake in your property. If you cannot pay within 30 months, the investor takes possession of your entire property, leaving you with nothing. This is generally seen as the harshest property tax forfeiture in the nation. A similar law was found unconstitutional by the Supreme Court a few years ago, forcing states to change their policy. Illinois did not, and as a consequence, several lawsuits were filed against Cook, DuPage, and Lake counties. The Cook County lawsuit managed to prove that tax sales violated the Fifth and Eighth Amendments. While Cook County is appealing, property forfeiture seems to be on hold, with more developments to come.

Property Tax Appeals Reach New Level of Popularity

Since Cook County’s infamous 2023 reassessment, taxpayers from every corner of Illinois have been embracing property tax appeals like never before. The BOR in Cook County claimed that 2025 had more appeals than any other time on record, and this was before the additional appeal window was opened. The collar counties around Chicago did the same, with homeowners and businesses alike challenging their assessments. Rural counties have also embraced appeals in record numbers. With all of Illinois being hit with rising taxes, it is only natural for the people to fight back.

O’Connor Aids Appeals by Collecting Evidence

While Cook County taxpayers have the option to go for an assessor appeal or one before the BOR, the rest of Illinois does not have the luxury. If you are outside of Chicago, then you only have the BOR as an option, meaning you have only one deadline to protest your taxes. The BOR requires more evidence than a simple appeal, meaning you will need to put your best foot forward. This means collecting all of the evidence you will need to present your case, while also finding an attorney to represent you at the BOR. Only lawyers can represent you in appeals, making finding one a must.

We at O’Connor are here to help. For over 50 years, we have been helping taxpayers across the nation. We can assist you by compiling evidence for your case. This not only includes basic information and in-depth analysis but also focuses on using our state-of-the-art databases to compare home sales and property values across the state, proving what the real worth of your home or business is. We will then coordinate your appeal with attorneys that we engage to assist you. These attorneys are all experts in the property tax field and will be your perfect partner. We will provide you and your attorney with all the evidence you need to win. Best of all, you will pay for none of this unless you can lower your taxes. If you are successful, then you pay us with a contingency fee drawn from the tax savings achieved. This means that there is no financial risk to signing up with us. 2026 will be even more complex than 2025, so it will pay big dividends to have some expert analysis in your corner.