Interest Calculations

Taxpayers can expect to receive a tax bill the middle of May. If you do not receive a tax bill call the Winnebago County Treasurer’s office at (815) 319-4400.  Office hours are Monday through Friday from 8 a.m. to 5 p.m. with the exception of holidays. Failure to receive the tax bill will not negate your tax liability.

Interest Calculations Form PDF

Change Address

Illinois Compiled Statutes, (35 ILCS, 200/20-20), requires “no change of address shall be implemented unless the person requesting the change is the owner of the property, a trustee or a person holding the power of attorney from the owner or trustee of the property.”

Billing Correction Form PDF

Property Tax Exemptions

The Supervisor of Assessments office provides more information on Property Tax Exemptions and the appropriate forms. Please visit their website for more details.

Tax District Contact Information

 Winnebago County Taxing District Contact Information List - May 2023 PDF

Tax Distributions

The following are links to past Real Estate Distribution Settlement sheets:

Freedom of Information Act

In compliance with the Illinois Freedom of Information Act (FOIA), notice is hereby given that the designated FOIA officer(s) for the Office of the Winnebago County Treasurer is Theresa Grennan. All requests for information regarding the Office of the Winnebago County Treasurer should be directed to the persons above at This email address is being protected from spambots. You need JavaScript enabled to view it..

As required by the Freedom of Information Act, all information held by the Winnebago County Treasurer's office is public information and is available upon written request.

The purpose of the Office of Winnebago County Treasurer is the collection, receipt, investment and disbursement of county funds. This office has 7 full time employees and 1 part time employee. The office hours are Monday through Friday from 8 a.m. to 5 p.m. The annual budget of the Treasurers office is $466,666.00.

FOIA requests may be filed in person during those hours, by mail or via e-mail. A response to the FOIA request will be provided to the requestor within five (5) business days from the day the office receives the request. Requests received by mail will be considered received on the business day the mail is received by the office. If a request is sent by e-mail during business hours on a business day, it will be considered being received on that day. If the e-mail is sent after business hours or on a non-business day, it will be considered received on the next business day. Saturdays, Sundays and legal holidays are not counted in the computation of the 5 day response period.

Any questions regarding this notice may be referred to the above-referenced FOIA officer at (815) 319-4400.