What are the deadlines for filing a complaint to the Assessor?
In Cook County, the assessment season generally begins in May and continues through late fall. The assessor allows a thirty-day filing window for each township in which complaints can be filed. These filing windows are spread fairly evenly through the assessment season. The filing deadlines are published on the Cook County Assessors web site fairly far in advance. No other Illinois county has a formal filing process. However, assessments can be negotiated with the local assessor at any time.
