Union County, IL Property Tax: $1,851/yr (2026)
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The effective property tax rate in Union County is 1.41% of assessed home value. On a home at the county median value of $131,700, that works out to about $1,857 per year, or $155 per month. Union County is located in southern Illinois, and is home to approximately 16,972 residents.
About Union County
Union County covers approximately 413.4 square miles in Illinois. The county is home to about 16,972 residents living in roughly 7,861 housing units, of which 67.6% are owner-occupied. The median household income is $56,420, and the median home was built in 1975.
Union County borders Alexander County, Jackson County, Johnson County, Pulaski County, Williamson County — useful comparisons if you're considering nearby areas with potentially different tax rates.
How Property Taxes Work in Illinois
Property taxes in Illinois are administered at the county level. Each county sets a millage rate applied to the assessed value of real property — the effective rate above accounts for any partial assessments and exemptions already built into the local tax base. Assessed value can differ meaningfully from current market value depending on how often the county reassesses and what fraction of market value it uses.
Most counties in Illinois offer exemptions that reduce the taxable assessed value: homestead exemptions for primary residences, senior exemptions, disability exemptions, and veteran exemptions are common. These reduce your effective rate below the county-wide average shown here. Contact the Union County Assessor's office to learn which exemptions apply to your property and when to file.
Union County vs. Neighboring Counties
| Location | Eff. Rate | Median Home | Annual Tax |
|---|---|---|---|
| Union County, IL | 1.41% | $131,700 | $1,857 |
| Illinois state average | 1.83% | — | $2,410* |
| Alexander County | 1.65% | $58,700 | $966 |
| Jackson County | 1.91% | $125,000 | $2,385 |
| Johnson County | 1.32% | $148,200 | $1,952 |
| Pulaski County | 0.82% | $81,000 | $668 |
| Williamson County | 1.71% | $145,600 | $2,490 |
| US national average | 1.10% | $281,900 | $3,101 |
*State average annual tax computed at Union County's median home value of $131,700. Source: US Census ACS 2023 5-year estimates.
Frequently Asked Questions
How does Union County's property tax rate compare to the rest of Illinois?
At 1.41%, Union County is lower than the Illinois state average of 1.83%. On a home at the county median of $131,700, that means about $1,857 per year — versus $2,410 at the state average rate, a difference of $553 per year. Compared to the national average of 1.10%, Union County is above average.
What's a typical annual property tax bill in Union County?
For a home at the county median value of $131,700, the annual property tax in Union County is approximately $1,857 — or about $155 per month. For a home worth $197,550, expect around $2,785 per year. For a $263,400 home, approximately $3,714 per year. Use the calculator above to estimate taxes for any assessed value.
Where do I appeal a Union County property tax assessment?
Property assessment appeals in Union County are handled by the Union County Assessor's office. Most jurisdictions require filing within 30–90 days of receiving your assessment notice — confirm the specific deadline with the assessor's office before submitting, as deadlines and procedures vary by county. A successful appeal can reduce your assessed value and lower your tax bill for the current and future tax years.
What exemptions are available in Union County?
Illinois counties commonly offer homestead exemptions for owner-occupied primary residences, senior citizen exemptions for qualifying homeowners aged 65 and older, exemptions for disabled residents, and veterans' exemptions. Each exemption reduces your assessed taxable value, which in turn reduces your effective tax rate below the county-wide 1.41% shown here. Contact the Union County Assessor's office to confirm which exemptions are available and the application deadlines.
Data sources: US Census Bureau ACS 2023 5-Year Estimates, US Census Gazetteer (2024), County Adjacency File