By far the most populous county in Illinois with roughly 5.2 million residents, Cook County is the second-most populous county in the nation (after Los Angeles County in California). The county comprises 1,635 square miles in the northeast corner of the state. Incorporated in 1831, Cook County includes 135 incorporated municipalities, including most of Chicago, and all of Evanston and Calumet City.

Tax Lien Auction Information

April 3, 2017

County Website

Cook County's 2017 tax lien auction was held in April. A total of 17,191 certificates with a face value of over $86 million were available for research on the DigiPan platform.


  • Cook County is by far the most popular among Illinois tax lien investors due to its population, accessible size and the number of available certificates.

  • Cook County typically releases certificate data during the middle of March. It is available in DigiPan within two days of release each year.