UPDATE: Many property tax exemptions will auto-renew. Applications, if needed, are available online.
The term Certificate of Error under sub-term Other in the Form Document Category Taxonomy term
The Senior Citizens Assessment Freeze Homestead Exemption (35 ILCS 200/15-172) allows you, as a qualified senior citizen, to have your home’s equalized assessed value (EAV) “frozen” at a base year value and prevent or limit any increase due to inflation.
Your Property Index Number (PIN) is printed on your tax bill, your property closing documents and deed, and notices from the Assessor's office (such as your assessment notice).
Don’t know the property’s PIN? Search by address.