When are property taxes due in Mercer County, Illinois?

Mercer County property taxes are due Varies (Cook Co.: March 1). A second installment is due Varies (Cook Co.: August 1). This deadline applies to all counties in Illinois.

What is the penalty for late property tax payment in Mercer County, Illinois?

The late payment penalty in Mercer County is 1.5% per month starting day after due.

How do I pay Mercer County, Illinois property taxes?

You can pay Mercer County property taxes via Online, mail, in-person.

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Mercer County Property Tax Due Date

Illinois

(309) 582-2524

2026 Property Tax Due Dates

Official Source

Installment 1

Varies (Cook Co.: March 1)

First installment (varies by county)

Installment 2

Varies (Cook Co.: August 1)

Second installment

Pay Taxes Online →

Penalty: 1.5% per month starting day after dueGrace period: None

Payment Methods

Online, Mail, In-Person

Mercer County Treasurer

Phone

(309) 582-2524

How to Pay

Online

Pay using credit card or e-check

Visit Website →

By Mail

Mail check payable to Mercer County Treasurer

Visit Website →

In Person

Visit the Treasurer's office

Visit Website →

Other Counties in Illinois

Adams Alexander Bond Boone Brown Bureau Calhoun Carroll

View all Illinois counties →

About Mercer County

Mercer County is a county in Illinois. According to the 2020 census, it had a population of 15,699. Its county seat is Aledo.

Source: Wikipedia — content available under CC BY-SA 4.0

Related Resources

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Due dates shown are for reference only. Contact your county treasurer's office to confirm official deadlines before making payments.