Skip to Content

Guide to Using the AARP Foundation Property Tax-Aide Self Service Site

How to Use Our Self-Service Tool to Apply for the Cook County Certificate of Error (COE)

The AARP Foundation Property Tax-Aide self-service tool has been designed to simplify state property tax relief applications. By using the tool, you will be able to easily verify if you qualify to file a Certificate of Error in Cook County, Illinois for tax years 2018 – 2022, and then complete the application. Upon completion of the application, you can download and/or print the application with the information you have entered. Then, mail the application to the Cook County Assessor’s office. Please note, the self-service tool is for the Certificate of Error in Cook County only.

  • The self-service tool works best on laptops, desktops, and tablets, but also work okay on mobile phones when turned in landscape mode. 

What Do You Need Before You Begin an Application

Before you begin, there are a few documents and pieces of information you’ll need to have on hand in order to complete your application:

  • A photo ID that verifies identity and occupancy in the tax year for which you are applying. (Example: a driver’s license/IL ID card, Matricula Consular ID card, or a City of Chicago ID card)
    • Please note that if your photo ID doesn’t reflect your property address you’ll need to include copies of one Photo ID from List B and one document from List C
List B (verify identity)List C (verify address)
IL Driver’s License/IL ID CardBank Statement
Matricula Consular IDLandline, cable or Internet bill
City of Chicago ID CardPay stub
US PassportSocial Security Award Letter
US Military ID CardVoting Record (from Cook County Clerk’s Office or Chicago Board of Elections)
Certificate of Naturalization (N-550/N-570) 
Permanent Resident Card (I-551) 
Refugee Travel Document (I-571) 
Employment Authorization (I-766) 

If you are applying to the Persons with Disabilities Exemption, one of the following documents must also be provided with your application:

  • Class 2 Class 2 Disabled Person Illinois Identification card from the Illinois Secretary of State’s office
  • Proof of Social Security Administration disability benefits which includes an award letter of total (100%) disability, pension statement, or statement showing compensation rated at 100%
  • Proof of Department of Veterans Affairs disability benefits which includes an award letter or certification letter, indicating you are receiving pension for non-service connected disability
  • Proof of pension for non-military service connected disability
  • Proof of Railroad or Civil Service disability benefits is an award letter of total (100%) disability

If you are applying to the Veterans with Disabilities Exemption, you’ll need:

  • All applicants, must provide a Disability Certification Letter from the U.S. Department of Veterans Affairs. 
  • First time applicants must also submit a certification letter from the VA and a Form DD214, certified by either the Cook County Clerk’s Office or Illinois Department of Veterans Affairs. This document is not required for those reapplying. 
  • A non-remarried surviving spouse of a disabled veteran applying for the first time or transferring the exemption must also provide their marriage certificate, the disabled veteran’s death certificate, and proof of property ownership

If you are applying to the Senior Freeze, you’ll need income verification documents. Be sure to include the total household income for calendar year 2021.

Important! You’ll Need to Complete Your Application in One Session

Please note that your COE application will not be saved. If you start an application, you will need to finish it in the same session. Otherwise, you will need to start over from the beginning.

What to Expect When Using The Self-Service Tool

Before starting the application, you will be asked to complete a brief demographics survey. This information will help us understand who participates and who does not participate in our programs so we may improve AARP Foundation Property Tax-Aide’s programs and outreach activities. We do not maintain your name or address information in our database, so none of your answers will be linked to your name or address. Whether or not you answer these questions will have no effect on your participation in Property Tax-Aide or any other AARP Foundation program. We would appreciate it if you would answer all of the questions to the best of your ability. However, you are free to select “Prefer not to answer” for any questions you do not want to answer.

Below is a step-by-step guide that you can refer to as you use the self-service tool:

Step 1: Click the link at the bottom of the page to redirect to the self-service tool

Step 2: Review and complete the consent form. Enter your name and check the first box to provide consent. (It is optional to check the second box to receive information about other services from AARP Foundation. If you do check the second box, you’ll be asked to provide an email address.) Scroll to the bottom of the screen and click Next.

Step 3: Read the demographic survey instructions and click Next.

Step 4: Complete the brief demographics survey. When you have answered all the questions, click Next at the bottom of the screen.

Step 5: You’ll answer some questions to determine if you meet the eligibility criteria for the COE exemptions. When you’re done, a pop-up box will appear letting you know, based on your answers, if you may or may not meet the eligibility criteria. If the pop-up box suggests that you may meet the eligibility criteria, click the continue button to advance to the application. 

Step 6:  Enter your information into the fields on the screen, then click Review

Step 7: Review to ensure that the information you entered is correct. If you need to make a change, you can do so directly on the screen. When you have completed your review, check the box and then print or download your application.

Step 8: Sign the application and mail it to the Cook County Assessor’s office, along with copies of the required documents and the signed Occupancy Affidavit that prints with your application.

Click here to complete a Certificate of Error for property tax relief in Cook County, Illinois

Back to top