Below is information on tax cases analyzed as part of the Treasurer's Office study "How Wealthy Investors are Making Millions Exploiting Illinois' Property Tax Law." The office examined the results of eight tax sales held from 2013 through 2019. For more information on this sale-in-error data and how it was obtained, please see "How the Study Was Done."

The Community Impact Map tab shows information on sale-in-error refunds in Cook County. You can view the total refund amount and the refund amount per capita for each municipality, and filter municipalities by their racial/ethnic majority. Refunds were aggregated based on the location of the properties that had sales in error. Municipal population totals and racial/ethnic majorities are based on the 2020 U.S. Census.

The Sale-in-Error Data contains a table of properties that received sales in error, along with the sale-in-error case number, error type, refund recipient and refund amount. You can search properties by municipality or Chicago community area, as well as by Property Index Number (PIN). You can download the full table here.

We encourage you to read the study to learn more about our data sources and how this affects taxpayers in Cook County.