The Ledger: Key Upcoming Dates
Key Upcoming Federal, Iowa, & Illinois Tax Deadlines
January 15, 2026
- Individual (Federal and Illinois) Q4 2025 estimated payment due
- Partnership (Illinois) Q4 2025 estimated payment due (PTET)
- S-corporation (Illinois) Q4 2025 estimated payment due (PTET)
January 20, 2026
- Sales Tax (Illinois) December 2025 return and payment due
- Sales Tax (Illinois) Q4 2025 return and payment due
- Sales Tax (Illinois) Annual 2025 return and payment due
February 2, 2026
- Individual (Iowa) Q4 2025 estimated payment due
- Partnership (Iowa) Q4 2025 estimated payment due (PTET)
- S-corporation (Iowa) Q4 2025 estimated payment due (PTET)
- Trust (Iowa) Q4 2025 estimated payment due
- Payroll (Federal, Iowa, and Illinois) Q4 2025 employer/withholding return due
- Payroll (Federal and Iowa) Annual 2025 employer/withholding return due
- Payroll (Federal, Iowa, and Illinois) 2025 W-2s and 1099’s due to recipients
- Sales Tax (Iowa) Annual 2025 return and payment due
- Sales Tax (Iowa) December 2025 return and payment due
February 20, 2026
- Sales Tax (Illinois) January 2026 return and payment due
March 2, 2026
- Sales Tax (Iowa) January 2026 return and payment due
March 16, 2026
- Partnership (Federal) 2025 return (or extension) and payment due
- S-corporation (Federal and Illinois) 2025 return (or extension) and payment due
March 20, 2026
- Sales Tax (Illinois) February 2026 return and payment due
March 31, 2026
- Sales Tax (Iowa) February 2026 return and payment due
April 15, 2026
- C-corporation (Federal and Illinois) 2025 return (or extension) and payment due
- C-corporation (Federal and Illinois) Q1 2026 estimated payment due
- Individual (Federal and Illinois) 2025 return (or extension) and payment due
- Individual (Federal and Illinois) Q1 2026 estimated payment due
- Partnership (Illinois) 2025 return (or extension) and payment due
- Partnership (Illinois) Q1 2026 estimated payment due (PTET)
- S-corporation (Illinois) Q1 2026 estimated payment due (PTET)
- Trust (Federal and Illinois) 2025 return (or extension) and payment due
- Trust (Federal) Q1 2026 estimated payment due
April 20, 2026
- Sales Tax (Illinois) March 2026 return and payment due
- Sales Tax (Illinois) Q1 2026 return and payment due
April 30, 2026
- C-corporation (Iowa) 2025 return (or extension) and payment due
- C-corporation (Iowa) Q1 2026 estimated payment due
- Individual (Iowa) 2025 return (or extension) and payment due
- Individual (Iowa) Q1 2026 estimated payment due
- Partnership (Iowa) 2025 return (or extension) and payment due
- Partnership (Iowa) Q1 2026 estimated payment due (PTET)
- S-corporation (Iowa) 2025 return (or extension) and payment due
- S-corporation (Iowa) Q1 2026 estimated payment due (PTET)
- Trust (Iowa) 2025 return (or extension) and payment due
- Trust (Iowa) Q1 2026 estimated payment due
- Payroll (Federal, Iowa, and Illinois) Q1 2026 employer/withholding return due
- Sales Tax (Iowa) March 2026 return and payment due
May 15, 2026
- Exempt Organization (Federal) 2025 return (or extension) and payment due
May 20, 2026
- Sales Tax (Illinois) April 2026 return and payment due
June 1, 2026
- Sales Tax (Iowa) April 2026 return and payment due
June 15, 2026
- C-corporation (Federal and Illinois) Q2 2026 estimated payment due
- Individual (Federal and Illinois) Q2 2026 estimated payment due
- Partnership (Illinois) Q2 2026 estimated payment due (PTET)
- S-corporation (Illinois) Q2 2026 estimated payment due (PTET)
June 22, 2026
- Sales Tax (Illinois) May 2026 return and payment due
June 30, 2026
- C-corporation (Iowa) Q2 2026 estimated payment due
- Exempt Organization (Illinois) 2025 return (or extension) and payment due
- Individual (Iowa) Q2 2026 estimated payment due
- Partnership (Iowa) Q2 2026 estimated payment due (PTET)
- S-corporation (Iowa) Q2 2026 estimated payment due (PTET)
- Trust (Iowa) Q2 2026 estimated payment due
- Sales Tax (Iowa) May 2026 return and payment due
July 20, 2026
- Sales Tax (Illinois) June 2026 return and payment due
- Sales Tax (Illinois) Q2 2026 return and payment due
July 31, 2026
- Payroll (Federal, Iowa, and Illinois) Q2 2026 employer/withholding return due
- Sales Tax (Iowa) June 2026 return and payment due
August 20, 2026
- Sales Tax (Illinois) July 2026 return and payment due
August 31, 2026
- Exempt Organization (Illinois) extended 2025 return due
- Sales Tax (Iowa) July 2026 return and payment due
September 15, 2026
- C-corporation (Federal and Illinois) Q3 2026 estimated payment due
- Individual (Federal and Illinois) Q3 2026 estimated payment due
- Partnership (Federal) extended 2025 return due
- Partnership (Illinois) Q3 2026 estimated payment due (PTET)
- S-corporation (Federal) extended 2025 return due
- S-corporation (Illinois) Q3 2026 estimated payment due (PTET)
September 21, 2026
- Sales Tax (Illinois) August 2026 return and payment due
September 30, 2026
- C-corporation (Iowa) Q3 2026 estimated payment due
- Individual (Iowa) Q3 2026 estimated payment due
- Partnership (Iowa) Q3 2026 estimated payment due (PTET)
- S-corporation (Iowa) Q3 2026 estimated payment due (PTET)
- Trust (Federal) extended 2025 return due
- Trust (Iowa) Q3 2026 estimated payment due
- Sales Tax (Iowa) August 2026 return and payment due
October 15, 2026
- C-corporation (Federal and Illinois) extended 2025 return due
- Individual (Federal and Illinois) extended 2025 return due
- Partnership (Illinois) extended 2025 return due
- S-corporation (Illinois) extended 2025 return due
- Trust (Illinois) extended 2025 return due
October 20, 2026
- Sales Tax (Illinois) September 2026 return and payment due
- Sales Tax (Illinois) Q3 2026 return and payment due
November 2, 2026
- C-corporation (Iowa) extended 2025 return due
- Individual (Iowa) extended 2025 return due
- Partnership (Iowa) extended 2025 return due
- S-corporation (Iowa) extended 2025 return due
- Trust (Iowa) extended 2025 return due
- Payroll (Federal, Iowa, and Illinois) Q3 2026 employer/withholding return due
- Sales Tax (Iowa) September 2026 return and payment due
November 16, 2026
- Exempt Organization (Federal) extended 2025 return due
November 20, 2026
- Sales Tax (Illinois) October 2026 return and payment due
November 30, 2026
- Sales Tax (Iowa) October 2026 return and payment due
December 15, 2026
- C-corporation (Federal and Illinois) Q4 2026 estimated payment due
December 21, 2026
- Sales Tax (Illinois) November 2026 return and payment due
December 31, 2026
- C-corporation (Iowa) Q4 2026 estimated payment due
- Sales Tax (Iowa) November 2026 return and payment due