Tax Extension Process

How Is Your Tax Rate Calculated?
April 2011 - Property Taxes
Property Values & Tax Extensions
February 2011 - Property Taxes
The Lake County Clerk is responsible for “extending” (calculating) property tax rates for all taxing districts in Lake County. Though the process is started annually, each cycle takes two years to complete, so the billing for any given tax year occurs in the year following.
Chart explaining the taxing districts and tax levy cycle
Year County Offices
(Chief Assessor, Clerk, Treasurer)
Taxing Districts (Schools, Villages, etc.)
Year 1
(Property Assessments & District Levies)


Township Assessors determine the assessed value (1/3 of fair market value) of each property as of January 1st, based on sales data from the prior three years.


The Chief County Assessor’s Office evaluates and equalizes assessments across all townships. Assessment notices (blue sheets) are mailed to taxpayers, who have only 30 days to appeal their assessment to the Board of Review.


The Board of Review hears appeals of assessments, making changes as necessary.


Each district’s governing board holds public meetings on the district’s annual budget and levy (request for property tax revenues) for the next fiscal year. The budget is filed with the County Clerk’s Office within 30 days of passage. The levy is filed with the County Clerk’s Office by the last Tuesday in December.

Click here (PDF) to see the public meeting schedule for local districts.

Year 2
(Property Tax & Collection)


The Board of Review continues its hearings. Revised assessments are submitted to the County Clerk’s Office at the beginning of March.

March - April

The County Clerk’s Office calculates preliminary tax rates based on the levy passed by each district, and the property values from the township assessors, as adjusted by the Board of Review and the state multiplier issued by the Illinois Department of Revenue.

The County Clerk’s Office also calculates and applies any limits on property taxes, based on statutes established by the state legislature and governor.

The County Clerk’s Office certifies the final rates to the County Treasurer’s Office for billing.

May - November

The County Treasurer’s Office sends out tax bills at the beginning of May, with two installments due in June and September. Collected taxes are distributed to the taxing districts on a regular basis. Final notices are sent to delinquent taxpayers in October before the taxes are sold.

***IMPORTANT*** By the time you get your tax bill, it is already too late to protest the taxes on the bill! The time to speak up is when you receive your assessment notice (the blue sheet) and when your taxing districts meet to discuss their budget and levy.

End of November / Beginning of December

The County Treasurer’s Office holds an annual tax sale, where tax buyers bid to pay the delinquent taxes in exchange for a lien on the property. Tax liens are turned over to the County Clerk’s Office for collection as part of the Tax Redemption Process.


Taxing districts submit any new bond ordinances by March 1st, and any abatements of current bonds by March 15th.


Taxing districts that are over their statutory property tax limits are notified by the County Clerk’s Office and submit appropriate cuts to their levies.