Mercer County, Illinois

How to appeal a Mercer County property tax assessment

HomeTaxChallenge has not verified the Mercer County 2026 Board of Review filing window. 2026 deadline: TBD. Check with your assessor (Mercer County Supervisor of Assessments) or the Mercer County Board of Review for the current deadline before filing. Illinois appeals are filed with the county Board of Review; the next level is the Property Tax Appeal Board (PTAB).

Steps

1. Look up your Mercer County parcel to confirm the PIN, township and current assessment.
2. Confirm the 2026 filing deadline and complaint form directly with the Mercer County Board of Review.
3. Choose a basis: overvaluation (recent comparable sales) or equity (similar assessed values). Non-farm residential property in Illinois is generally assessed at one-third of fair cash value.
4. File the complaint and evidence with the Board of Review before the deadline. The next level is the Illinois Property Tax Appeal Board (PTAB).

HomeTaxChallenge does not offer a comparable-sales screening or savings estimate for Mercer County yet. Questions: contact@hometaxchallenge.com.

Disclaimer: HomeTaxChallenge is not a government agency and is not affiliated with Mercer County. This is informational and not legal, tax, or appraisal advice.