Making the Illinois Replacement Tax Payment

As an S Corp owner in Illinois, your business is subject to the Personal Property Replacement Tax, a state-level tax on the net income of "pass-through" entities. Staying on top of these payments ensures your business remains in good standing and avoids unnecessary penalties.

For businesses operating under an S Corp election in Illinois, there are two primary payment types handled through the state's portal:

• Annual Tax Return (Form IL-1120-ST): This is the S Corp’s annual business tax return, typically due on March 15th annually for calendar year businesses
• Quarterly Estimated Payments: Estimated payments are suggested to help you reduce the risk of large balances due at the time of filing and reduce the risk of underpayment penalties and interest. For Illinois businesses, these are generally due on the 15th day of the April, June, September and January of the tax year

This guide will walk you through making payments to Illinois.

My Tax IL Account Sign Up Steps

You’ll need to create a business account to pay your S Corp’s Replacement Tax quarterly estimates or Business Tax Return balance due. 

1. Visit the My IL Business Taxes page and click the “Go To Services” link. Click “Sign up” under the log in fields. 
2. You’ll see Individual Income Tax Letter (ignore this) and follow the instructions for businesses - click the Next button.
3. Select FEIN, enter your S Corp’s EIN number (you can find a copy of your EIN or Form 2553 in your Collective Documents, both will have your business EIN). Then click the Next button.
4. Follow the remaining steps to complete your S Corp’s My IL Tax account set up. If you run into any issues, please contact us at Rev.MyTaxHelp@illinois.gov or call us at 1-800-732-8866.

Making the IL Replacement Tax Payment

Visit the MyTaxIL page and click “Go to Services” account using your S Corp’s login credentials (this is a business tax payment paid from your business checking account). Once signed in you will see your S Corp business name at the top left to confirm you’re in the correct account. 

1. Within the Business Income Tax tile on the right side under Account Options, you will select the Make an Estimated Payment option to the right in blue. 

2. Under Account Options click the Make an Estimated Payment option in blue.

3. Select the Filing Period by clicking the date in blue that aligns with the tax year you’re making the IL Replacement Tax payment towards. QTE and IL Business Tax Return balances due will be for the calendar year ending date in which the payment should be applied. 
   1. Note: Q4 estimates are typically due January 15th of the new year but should be applied to the previous calendar year (e.g., a 2025 Q4 payment has a filing period of 12/31/2025).

4. Once you’ve selected the correct Filing Period, you will see the Payment Schedule for IL-1120 ST, this is for making payments towards your IL Business Tax Return, QTEs or balance due by March 15th. Payments you’ve made for this period (calendar year) will appear as well. Click the first available “Add Payment” text in blue on the left. 

5. You will be prompted to add the payment date and amount. 
   1. Please reference your Collective Taxes dashboard for your IL Replacement Tax QTE amount, or your IL Business Tax Return available in your Collective Documents for the balance due amount. 
   2. After you’ve confirmed the payment amount, click the “Submit” button.

6. You will be asked to enter your MyILTax login password as you complete your payment method details and complete the payment submission.
7. Please print your confirmation as a PDF and upload to your Collective Taxes dashboard. 

Disclaimer: The information contained in this document is provided for informational purposes only and should not be construed as legal, financial, or tax advice. It is not intended to be a substitute for obtaining legal, accounting, or other financial advice from an appropriate and/or licensed  adviser, or for the purpose of avoiding U.S. Federal, state or local tax payments and penalties.