You must enter your property number exactly as it appears on your property tax bill or assessment notice. Complete Form PTAX-203-B, Illinois Real Estate Transfer Declaration Supplemental Form B. 11 Full actual consideration.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. Duplicate or Overpayment Refund. Property Tax Bill Assistance. Fritz Kaegi, Cook County Assessor. This savings is in the form of a deduction on the second-installment real estate tax bill. The purpose of this form is to assist qualified homeowners in Chicago to alleviate the financial burden of property taxes.