Rate Breakdown

Property taxes in Clinton County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in Clinton County

In Clinton County, Illinois, property taxes are calculated based on the assessed value of a property and the local millage rate set by county, city, school district, and special taxing authorities. The county assessor’s office performs an annual valuation, typically using comparable sales and property characteristics to determine the market value. The assessed value is then multiplied by the millage rate—expressed in mills (thousandths of a dollar per dollar of assessed value)—to produce the dollar amount of tax owed. For example, a property assessed at $120,000 with a combined millage rate of 5.5 mills results in an annual tax of $660. The millage rate is publicly posted and can change each tax year, reflecting budget needs of the various taxing entities.

Available Exemptions

Illinois offers several exemptions that can reduce the taxable basis of a property. In Clinton County, homeowners with a homestead exemption receive a reduction of up to $4,000 on the assessed value of a primary residence, which translates to a payment saving at the applicable millage rate. Senior citizens aged 62 or older qualify for a full exemption, meaning no property tax is assessed on their primary residence. Individuals with a qualifying disability—such as blindness, paraplegia, or other severe conditions—may also receive a discount of up to $10,000 on the assessed value. Veterans, especially those with disabilities from service, can apply for a veteran exemption that reduces the assessed value by $10,000. All exemptions must be claimed by filing the proper application with the county assessor before the deadline listed on the tax bill.

Payment Schedule & Deadlines

Clinton County issues tax bills in two installments. The first installment is due on April 15, and the second installment on September 15. Each installment is approximately half of the total annual tax amount. Property owners may choose to pay the instalments in full a few days early to avoid any record‑keeping complications. If a payment is not received by the due date, late fees of 5% per month may apply, and the unpaid balance can be added to the county’s assessment roll for collection through a tax lien process. Failure to pay within one year of the initial due date may result in a foreclosure proceeding. Paying by check, online banking, or using the county's automatic debit program ensures timely processing.

Appealing Your Assessment

Should a property owner disagree with the assessed value, an appeal may be filed with the Clinton County Tax Record Board. The appeal must be submitted in writing, including a detailed explanation of the discrepancy and supporting documents such as recent sales comps, appraisal reports, or building plans. The deadline for filing is 60 days after the original tax bill is issued. Once received, the Tax Record Board will convene a hearing, allowing the homeowner to present evidence and challenge the assessor’s valuation. The board may adjust the assessed value upward or downward based on the merits of the case. An appeal is a valuable tool to potentially lower tax liability, but it requires careful documentation and timely action to be successful.