Piatt County Supervisor of Assessments

Piatt County Tax Search

Click here to go to the Piatt County Tax Search Website where you can find real estate tax information for properties in Piatt County.

2019 Piatt County Real Estate Assessment Publications

Click here to view the 2019 Piatt County Real Estate Assessment Publications for all townships

Piatt County GIS Web Maps

The Piatt County Geographical Information System (GIS) offers enhanced search capabilities including lookup by common post office address, PIN, and street intersection. Click here to go to the Piatt County GIS site.

GIS Interactive Map Subscription Agreement

Advanced features of the Piatt County GIS are only avaiable by subscription. The annual fee for these additional features is $40.00. To subscribe, please fill out the Interactive Map Subscription Agreement form and follow the instructions at the bottom. Following approval of your contract, you will be provided with access information.


The Office of the Supervisor of Assessments was created by state law to provide statistical assessment performance data to the Illinois Department of Revenue. It is the responsibility of the county's township assessors to assess the properties in their jurisdictions. Sales information is compiled from the transfer declarations recorded in the County Clerk's office. Property record cards are available for each property in the County. Aerial maps are maintained in the office. There are approximately 11,306 parcels in Piatt County at this time. The office administers the following exemptions:

Click on a highlighted exemption for a printable form.   Pdf Reader required
PLEASE NOTE: All forms, including "Name/Address Change", must be mailed or delivered to our office in person. Faxes will not be accepted.

Additional forms and documents

Name/Address Change.Note: If submitting by mail, form must be notarized or a copy of your driver's license must be enclosed.

Property Assessment and Equalization: A publication of the Illinois Department of Revenue

USDA Historic Aerial Photography: Information on the United States Department of Agriculture's Farm Service Agency aerial photography program.

Duties of the Supervisor of Assessment:

Supervisor of Assessments
Piatt County Courthouse
101 W. Washington
Monticello, IL  61856