Should I appeal to the Cook County Assessor, the Board of Review, or both?

Cook County is unusual in offering two separate administrative appeal stages in the same year, run by two independent offices:

1. The Cook County Assessor — sets your assessed value and offers the first appeal during your township's window. File at the Assessor's appeals system. 2. The Cook County Board of Review (BOR) — a separate agency that opens its own township windows after the Assessor closes, and reviews assessments independently. File at the BOR online portal.

The common strategy is to do both. Appeal to the Assessor first. If the Assessor grants a full reduction you are satisfied with, you may stop. If the Assessor denies your appeal or grants only a partial reduction, file again with the Board of Review when your township opens there — the BOR conducts a fresh review and can reduce the value further. Because the two windows run sequentially, you usually have time to see the Assessor's result before the BOR window opens.

You can skip the Assessor. Appealing to the Assessor is not a prerequisite for the Board of Review — you may file only with the BOR. But doing both maximizes your chances, and it costs nothing: both stages are free.

You must go through the BOR to escalate further. To reach the state-level Illinois Property Tax Appeal Board (PTAB) or a circuit-court tax-objection complaint, you must first have a Board of Review decision. Under 35 ILCS 200/16-160, the appeal to PTAB is taken within 30 days of the BOR's written decision. So even if you are confident, completing the BOR stage preserves your right to escalate.

Bottom line: treat the Assessor and Board of Review as two shots at the same goal in one year, and the BOR decision as the gateway to any higher appeal.