Property Tax Appeal · Cook County, IL
Appeal your property taxes
in Cook County, IL.
Home to Chicago, Cook County homeowners appeal through Illinois’s system: the township or county assessor sets the value, and the county Board of Review (then PTAB) hears the case. Boards act on evidence of market value as of the assessment date — a licensed, USPAP-compliant appraisal is that evidence. Start with the $5 check to see what you’d save.
- Valued as of January 1 (the county lien date)
- 3+ comparable sales within ~1 mi, sold within 24 months
- Cover letter addressed to the Cook County Assessor
- Delivered upload-ready for electronic filing
Illinois assessments are a fraction of market value (one-third outside Cook; Cook residential is assessed at 10% of market value before equalization) — your appeal still comes down to demonstrating what the home is actually worth, which the assessor then converts to assessed value.
Cook County questions
The annual deadline is March 31. File before then or wait until the next cycle — rush appraisal delivery is available when the window is close.
Illinois assesses on a cycle — Cook County reassesses each township every three years; most other counties run quadrennial cycles with annual updates. When your township’s notices publish, a roughly 30-day appeal window opens: first with the assessor (in Cook, the Assessor’s Office accepts appeals directly), then the county Board of Review, and if needed the state Property Tax Appeal Board (PTAB) or circuit court. Effective tax rates in Illinois are among the highest in the nation, so even a modest assessment cut compounds into real money.
Comparable sales as of the assessment date, adjusted for the differences between those homes and yours — the substance of a licensed appraisal. county Board of Review (then PTAB) panels see hundreds of cases; a signed, USPAP-compliant report is the document they can act on.
We’re not an AVM, a computer model, or a real-estate agent estimate. Every report is prepared under the Uniform Standards of Professional Appraisal Practice (USPAP) and signed by a licensed appraiser in your state — the same qualification required for mortgage appraisals.