How does the Cook County Assessor determine my property taxes?


The Cook County’s Assessor’s Office is responsible for valuing the more than 1.6 million residential parcels in Cook County. Cook County is divided into three assessment districts (City, North and South). Each of the assessment districts is valued once every three years.

The Cook County Assessor’s Office uses a computer-assisted mass-appraisal method to value residential properties. This computerized sales comparison model considers several different value components including, but not limited to, sales of comparable properties, land, location, building square footage, and construction type. These are some of the very same factors that would be considered by an appraiser seeking to value a property.

Home sales volume is significant in Cook County in virtually every neighborhood, making sales the most reliable source of market value. Residential properties are assessed as of January 1st of the current year and use three to five years of prior sales information. Multiple sale years also increase the stability of market value predictions and smooth out market fluctuations.

Why should I appeal my taxes?

Take your cue from commercial property owners. They are considered more sophisticated than residential property owners. This is probably due to their focus on the bottom line of their investment. Most commercial property owners appeal their property taxes after each assessment, every three years, because property taxes are a large portion of their expenses. Residential property owners should also protect their bottom line.

The property tax system in Cook County is one of the most complicated in the United States. The property owners who successfully appeal their taxes save money. The money they save is not lost from the tax base of the county, it is shifted as an additional tax burden upon those who do not successfully appeal. More citizens of Cook County are appealing their property taxes every year and this additional tax burden is growing at an alarming rate. You do not want to be in the group of property owners who do not appeal.

What is the advantage of a flat fee versus a a split fee?

We believe that paying a flat fee is much a cheaper approach. Your costs are known, and there are no future bills. With a fee split, there could be a thousand dollar or higher invoice in your future. This is a potential budget buster. Flat fees avoid the good news/bad news dilemma common in property tax appeal.

What is the Board of Review?

The Cook County Board of Review is a quasi-judicial body, consisting of three co-equal elected commisioners, which “sits as an appellate tribunal” to correct errors in the Assessor’s valuations. The agency is designated to review property tax appeals and to reduce assessments where supported by the evidence.

The Cook County Board of Review heard approximately 270,000 appeals last year. Cook County has 1.6 million parcels of land. Approximately 15% of property owners appeal their property taxes.

How does the county determine my neighborhood (listed as NBHD. on the Assessor’s Website)?

Great question. We wish we could give you a definite answer. However, we have found neighborhoods that include as many as three (3) different cities/towns. We have found neighborhoods with only one property listed. We have found properties that are on the same block that have different neighborhood numbers.  We are analyzing the information in an effort to answer this question.