Clay County has received a final property assessment equalization factor of 1.0000 for the 2025 tax year, according to David Harris, director of the Illinois Department of Revenue (IDOR).
The property assessment equalization factor, also known as the “multiplier,” is used to ensure uniform property assessments among counties in Illinois. This process is important because many of the state’s approximately 6,600 local taxing districts, such as school and fire protection districts, extend across multiple counties. Without this equalization process, taxpayers with similar properties could face significant differences in their tax burdens.
According to state law passed in 1975, most property in Illinois should be assessed at one-third of its market value. However, farm properties are treated differently: while homesites and dwellings on farms follow standard assessing and equalization procedures, farmland itself is assessed at one-third of its agricultural economic value and does not use the state equalization factor.
In Clay County, assessments are currently at 33.33% of market value based on sales data from 2022 through 2024. The new multiplier applies to taxes payable in 2026. Last year’s multiplier for Clay County was also set at 1.0000.
The final assessment equalization factor was determined after a public hearing on a tentative factor issued on November 8, 2025; that tentative figure was also set at 1.0000.
Each year, IDOR determines the equalization factor for every county by comparing sale prices over three years with the assessed values assigned by local officials. If the average level of assessment matches one-third of market value over that period, the multiplier remains at one; if it is higher or lower than that benchmark, the multiplier adjusts accordingly.
A change in this multiplier does not directly affect total property tax bills. Instead, local taxing bodies determine how much money they need each year to provide services; if their requested amount does not increase from previous years, overall property taxes will remain stable even if assessments rise.
“The assessed value of an individual property determines what portion of the tax burden a specific taxpayer will assume. That individual’s portion of tax responsibility is not changed by the multiplier,” said Harris.
