You should call the Assessor's Office at (312) 443-7550 to be sure you are receiving all the property tax exemptions for which you are entitled. As the owner of a property in the Cook County Class 9 Program, you are required to file an annual affidavit with the Cook County Assessor's Office.It's also worth noting that many states, but not. Illinois, tax "personal property" like cars, boats and business equipment. A property tax exemption is like a discount applied to your EAV. If you qualify for an exemption, it allows you to lower your EAV. The Cook County RTLO provides renters' rights and landlord protections to Cook County suburban residents. What can you do if you are a tenant being locked out? This would result in a lower property tax bill for you. Complete Form PTAX-203-B, Illinois Real Estate Transfer Declaration Supplemental Form B. 11 Full actual consideration.