Due diligence / Cook County
Cook County
property taxes.
Property taxes can make or break a Chicago commercial deal. Here is what every buyer should understand before writing an offer.
The essentials / 01 — 06
Underwrite the tax,
not just the price.
Tax rules and rates change, and every parcel is different. Confirm specifics with your attorney and a Cook County tax professional.
See the due diligence checklistWhy taxes matter before you buy
Cook County commercial property taxes are among the highest in the country and can be one of the largest operating expenses on a building. Understanding the tax picture of a specific parcel is a core part of underwriting any Chicago-area purchase.
How assessment works
The Cook County Assessor values properties on a three-year reassessment cycle, with the City of Chicago, northern suburbs and southern suburbs reassessed in rotating years. Commercial properties are assessed at 25% of market value, compared to 10% for residential — a classification difference that drives much of the tax burden.
The role of the equalizer and tax rates
Assessed values are multiplied by the state equalization factor, then by the local tax rate, which varies by municipality and taxing districts. Two similar buildings in different suburbs can carry very different tax bills.
Appeals are common — and expected
Many commercial owners appeal assessments, first to the Assessor and then to the Cook County Board of Review. A history of appeals, or the lack of one, affects what you should expect to pay after closing. Buyers often review a parcel’s appeal history as part of due diligence.
Reassessment risk after a sale
A purchase price above the assessed value can invite a higher assessment at the next reassessment. Underwrite the deal using a realistic post-sale tax estimate, not just the seller’s current bill.
What to review in due diligence
Pull the parcel’s PIN history, current and prior tax bills, assessment and appeal records, any exemptions or incentives, and whether taxes are current. Your attorney and a tax professional can help interpret what the numbers mean for your hold period.
Looking at a specific property?
Let's review the tax picture.
Rosemary can help you evaluate a parcel's tax history and what it means for your purchase.