Uniformity Appeals Explained

The core idea: equal treatment

The Illinois Property Tax Code (35 ILCS 200/9-145) requires that all property in a taxing district be assessed uniformly— at the same percentage of market value. If your property is assessed at a higher rate than comparable properties, that's a violation of uniformity, and you have grounds to appeal.

You don't need to argue that your home is worth less. You only need to show that similar homes nearby are assessed at a lower rate than yours.

What “comparable” means

For a uniformity appeal at the Cook County Board of Review, comparable properties must be:

• ·In the same CCAO neighborhood code as your property
• ·The same property class (e.g., Class 2-02 single family)
• ·Similar building size — typically within ±20% of your square footage
• ·Similar age — typically within 15 years of your year built

You generally need at least 3 valid comparables. The Board of Review recommends submitting 5 or more for a stronger case.

Where to file

You can appeal at two levels in Cook County:

• 1.
  CCAO (Cook County Assessor's Office) — first appeal window, opens after reassessment notices go out. Online filing at assessor.cookcountyil.gov. Free to file directly.
• 2.
  Board of Review (BOR) — second appeal window, typically opens 3–6 months after CCAO closes. Online filing at cookcountyboardofreview.com. Free to file directly. This is where uniformity arguments tend to be strongest.

Filing deadlines are township-specific and posted each year. Missing the deadline means waiting until the next reassessment cycle (up to three years).

What TaxedTooMuch provides

TaxedTooMuch pulls your property from the CCAO's open dataset, finds valid comparables in the same neighborhood using the same criteria the Board of Review uses, and calculates your assessed value per square foot versus the neighborhood average.

If data suggests a possible over-assessment, we generate an informational data report with:

• ·Your property details and $/sqft assessment rate
• ·Up to 20 comparable properties, sorted by $/sqft
• ·The estimated assessment difference in dollars
• ·General filing information for your township

The report provides informational data you may use as supporting information if you choose to file an appeal. You can file on your own or share it with a tax attorney or consultant. TaxedTooMuch does not file appeals on your behalf. Flat fee of $49.