Madison County Assessor

Find Madison County Illinois assessor, assessment, auditor's, and appraiser's office, revenue commissions, GIS, and tax equalization departments. Assessors provide information on property and land tax assessment, property listings, values, valuations, property search, and records.


Alton Township Assessor 102 East Broadway Alton IL 62002 618-462-0671


Edwardsville Assessor 300 West Park Street Edwardsville IL 62025 618-656-6305

Madison County Assessor's Office 157 North Main Street Edwardsville IL 62025 618-692-6270

Venice Township Assessor 910 Madison Avenue Madison IL 62060 618-452-3033

What is an Assessor?

An assessor determines the values of properties in a local jurisdiction, such as a county or state. This assessment is then used to determine the taxable value of each property and the corresponding property tax amount. An assessor works with an auditor's office or local revenue commission to determine real estate and property value increases and decreases. The department may work with an appraiser's office on new construction projects to produce property and land tax assessments.

Assessors use a variety of GIS maps and tax equalization tools to determine valuations within their specific boundaries. The assessor determines which properties are exempt from property taxes and ensures that taxpayers aren't overburdened, as well as ensuring that properties aren't undervalued or overvalued. Assessors may provide valuable information for related property searches.