The Illinois Department of Revenue announced on Apr. 6 that DuPage County has been assigned a final property assessment equalization factor, or multiplier, of 1.0000 for the 2025 tax year.
The equalization factor is used to ensure uniform property assessments among counties across Illinois. This process is important because many local taxing districts, such as school and fire protection districts, cross county lines and require consistent assessments to avoid disparities among taxpayers with similar properties.
David Harris, director of the Illinois Department of Revenue (IDOR), said the new multiplier reflects that assessments in DuPage County are at approximately one-third—33.32 percent—of market value based on sales from 2022 through 2024. “The property assessment equalization factor, often called the ‘multiplier,’ is the method used to achieve uniform property assessments among counties, as required by law,” Harris said.
The department explained that if the three-year average level of assessment matches one-third of market value, the equalization factor will be set at one. The current figure applies to taxes payable in 2026 and follows last year’s identical multiplier for DuPage County. The tentative factor was also set at 1.0000 after a public hearing held earlier this year.
A change in the equalization factor does not directly impact total property tax bills; those amounts are determined by local taxing bodies when they request funds for services each year. Individual tax responsibility depends on assessed value rather than changes in the multiplier itself.
The Illinois Department of Revenue operates within state taxation and revenue management and aims to fairly administer state tax laws while efficiently collecting revenues and providing accurate information according to its official website. The agency also promotes diversity and equity within its workforce and customer service practices as stated on its official site.
