Duplicate or Overpayment Refund. The Portal consolidates information and delivers Cook County taxpayers a one-stop customer service website.Only taxing districts that collected and received personal property taxes for the 1977 tax year (1976 for Cook County) are eligible to receive PPRT payments. Property tax exemptions are savings that contribute to lowering a homeowner's property tax bill. The most common is the Homeowner Exemption. This tax is imposed on the retail purchase of tangible personal property titled or registered with the State of Illinois to an address located in Cook County. Cook County Treasurer's Office 118 North Clark Street, Room 112 Chicago, Illinois 60602 (312) 443-5100