Complete the contact form page and attach a file for ONE of the following proofs of payment for each payment. Cook County Treasurer's Office 118 North Clark Street, Room 112 Chicago, Illinois 60602 (312) 443-5100It contains your home's Property Index Number (PIN), characteristics, estimated fair market value, and assessed value. The Cook County Clerk's office has a variety of property tax responsibilities. For more information visit the Cook County Clerk's page on Real Estate and Tax Services. You can search Delinquent Property Taxes online. To pay your Property Taxes, please click below to be taken to the website of the Cook County Treasurer.