Tax Extension and Rates

The Clerk's Tax Extension Unit is responsible for calculating property tax rates for all local governments, or taxing districts, in Cook County that authorize the collection of revenue through real estate taxes.

How tax rates are calculated:

  • The Cook County Assessor's office establishes property valuations.
  • Taxing districts file their levy requests with the Clerk's Tax Extension Unit.
  • To produce the revenue requested, the Tax Extension Unit uses the levy to determine the tax amount to be "extended" against all properties located within the boundaries of the taxing district.
  • The Clerk's Tax Extension Unit determines the rate needed per $100 of taxable value to generate the requested revenue, based on the value of all taxable property within the district boundaries

(Note: Limits under Illinois law can restrict the revenue, either through statutory maximum rates for certain purposes and/or through "tax caps," which limit the total amount extended. Extension limits are not applied to funds needed to pay bonds and certain other charges.)


Interactive Tax Reports (Query by District, Year & Report type):

Tax Reports Available Online:

Cook County Annual Tax Rate Report


2018 2017 2016 2015 2014 2013 2012


2010 2009 2008 2007 2006 2005 2004
Cook County Tax Code Rate Summary (10-year report)


Cook County Agency EAV and Extension by Class

2019 EAV by Class (PDF)

2019 Extension by Class (PDF) 

2018 EAV by Class (PDF)

2018 Extension by Class (PDF) 

2017 EAV by Class (PDF)

2017 Extension by Class (PDF) 

2016 EAV by Class (PDF)

2016 Extension by Class (PDF) 

2015 EAV by Class (PDF)

2015 Extension by Class (PDF) 

2014 EAV by Class (PDF)

2014 Extension by Class (PDF) 

Tax Data Available Online:

Cook County Tax Code Agency Rates (Excel)





2015 2014 2013





2008 2007 2006
Agency Tax Rate Reports (Excel)




2016 2015 2014  

Other Data Available Online:

Filing deadlines for taxing districts

Budgets and Appropriation Ordinance
  • Must be filed within 30 days of their adoption. Included with the filing must be an estimate of revenue, by source, for the following fiscal year signed by the chief financial officer of the district.
Tax Levies
  • Must be filed on or before the last Tuesday in December of the given tax year.
Truth in Taxation
  • A certificate stating compliance with the Truth in Taxation Law must be filed with the levy ordinance. You may download a sample copy of a Truth in Taxation Certificate*.
Annual Financial, Treasurer and Audit Reports
  • Many taxing districts must file these reports within six months from the end of the fiscal year.
How to File
  • Taxing district documents may be filed through the mail or in person to:
       Cook County Clerk
       Tax Extension Department
       118 N. Clark St., Room 434
       Chicago, IL 60602

    Or through our secure Taxing District Portal


For more information

Please see the applicable provisions of the Illinois Compiled Statutes. Filing requirements for different types of taxing districts vary, and many requirements change periodically.

You may also e-mail questions to the Clerk's Tax Extension Unit at [email protected].

Need more help?

Go to Tax FAQs and Glossary of Tax Terms