2023 Illinois State Tax Deadlines
Illinois Individual Income Tax Filing deadlines and extensions for 2023.
If you are a resident or have been involved in significant business operations within Illinois then you might be required to file Illinois State Taxes. We look at the most important tax deadlines and tax extensions for Illinois in 2023.
C Corporation
Illinois C Corporation Tax Deadlines for 2023
You must file & pay Corporate Income Taxes in Illinois by April 16, 2024
Applicable forms:
Form IL-1120 - Corporation Income and Replacement Tax Return
Extension to File Taxes in Illinois for 2023
You must send payment for taxes in Illinois for the fiscal year 2023 by April 16, 2024.
The Extension Deadline is October 15, 2024 to file your Illinois income tax return.
Illinois automatically grants 6 months extensions on filing corporate income tax returns. This means you do not need to file for an extension in Illinois.
This is an extension to FILE, not an extension to PAY - payment is still due April 16, 2024
Pass-Throughs
Illinois S Corporation & Partnership Tax Deadlines for 2023
You must file in Illinois by March 15, 2024
Applicable forms:
Form IL-1120-ST - Small Business Corporation Replacement Tax Return
Form IL-1065 - Partnership Replacement Tax Return
Extension to File S Corporation & Partnership Taxes in Illinois for 2023
You must send payment for taxes in Illinois for the fiscal year 2023 by March 15, 2024.
The Extension Deadline is September 16, 2024 to file your Illinois income tax return.
Illinois automatically grants 6 months extensions on filing S Corporation income tax returns. This means you do not need to file for an extension in Illinois.
This is an extension to FILE, not an extension to PAY - payment is still due March 15, 2024
Illinois Individual Tax Deadlines for 2023
Estimated Tax Deadline for Illinois 2023
Estimated tax payments are made:
- April 18, 2023
- June 15, 2023
- September 15, 2023
- January 15, 2024
See IL-1040-ES for the amount to pay with each voucher.
Individual Tax Deadline for Illinois 2023
You must file & pay Individual Income Taxes in Illinois by April 16, 2024
File Online - MyTax Illinois
File by Mail must be postmarked by the due date
Applicable forms:
IL-1040 - Full Time Resident
Schedule NR - Non-Residents & Part-time Residents
Extension to File Taxes in Illinois for 2023
You must send payment for taxes in Illinois for the fiscal year 2023 by April 16, 2024.
The Extension Deadline is October 15, 2024 to file your Illinois Individual Income tax return.
Illinois automatically grants 6 months extensions on filing personal income taxes. This means you do not need to file for an extension in Illinois.
This is an extension to FILE, not an extension to PAY - payment is still due April 16, 2024
Estates Tax Deadline for Illinois in 2023
The estate tax return is due nine months after the date of death.
Farmer and Fisherman Taxes for Illinois 2023
If at least 2/3 of your gross income for the taxable year is derived from farming, you may pay estimated tax at any time on or before January 15, 2024. If you wait until January 15, 2024, you must pay the entire balance of the estimated tax. However, if farmers file their tax return on or before March 1, 2024, and pay the total tax at that time, they need not file estimated tax.
Sources
- https://www2.illinois.gov/rev/individuals/filingrequirements/Pages/extension.aspx#:~:text=Note%3A%20Taxpayers%20affected%20by%20the,time%20to%20file%20your%20return
- https://www2.illinois.gov/rev/programs/mytax/Pages/il-1040.aspx
- https://www2.illinois.gov/rev/questionsandanswers/Pages/62.aspx
- https://www2.illinois.gov/rev/research/publications/bulletins/Documents/2023/FY2023-02_N1022.pdf
The material discussed on this page is meant for general illustration and/or informational purposes only and is not to be construed as investment, tax, or legal advice. You must exercise your own independent professional judgment, recognizing that advice should not be based on unreasonable factual or legal assumptions or unreasonably rely upon representations of the client or others. Further, any advice you provide in connection with tax return preparation must comply in full with the requirements of IRS Circular 230.
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