Illinois Property Tax Deadlines: Second Installment Due Dates for 2025
- rjcurington
- Aug 20
- 2 min read
DISCLAIMER: This blog post should not be construed as legal advice.
Property owners and investors across Illinois should be mindful of upcoming second installment property tax deadlines for 2025. Missing a due date can result in penalties, so it’s important to stay organized and aware of your county’s schedule.
Below, we’ve compiled a county-by-county list of second installment due dates for the 2025 tax cycle. If your county is not listed, contact our office and we’ll help you verify the correct information.
2025 Second Installment Property Tax Due Dates by County
Peoria County — September 10, 2025
DuPage County — September 2, 2025
Sangamon County — September 5, 2025
Kendall County — September 4, 2025
Cook County — TBD (not yet released)
Ogle County — September 12, 2025
Lake County — September 4, 2025
McLean County — September 4, 2025
Will County — September 2, 2025
Lee County — September 5, 2025
Henry County — September 12, 2025
DeKalb County — September 4, 2025
Kane County — September 2, 2025
Warren County — October 15, 2025
Jackson County — November 13, 2025 (installments on Sept. 16 and Nov. 13)
Rock Island County — August 18, 2025 (4-installment plan: June 18, Aug. 18, Sept. 18, Nov. 18)
Key Takeaways
Mark your calendar. Many counties share the same early-September deadlines.
Check your county. Not all counties follow the same installment schedule (e.g., Rock Island and Jackson).
Cook County owners. Deadlines have not yet been published—stay tuned for updates.
Avoid penalties. Late payments can result in significant interest or fees.
Our firm works closely with investors, homeowners, and businesses across Illinois to ensure tax compliance and avoid unnecessary penalties. If you’re unsure about your property tax obligations, or if your county is not listed above, please reach out to Curington Law, LLC today and we’ll guide you through the process. We’re here to help you make informed decisions and achieve your real estate goals.
