UPDATE 12/31/21: Sigh. The step-by-step instructions I painstakingly wrote out below, with screenshots (for making business replacement income tax estimated and extension payments) are now out-of-date because IDOR revamped their MyTaxIllinois website in September (grrrrr). Please see this blog post instead: How To Make IL Dept Of Rev (IDOR) Business Tax Payments Online: Estimates & Extensions – UPDATED | The Dancing Accountant — the basic concepts are the same, but the layout and workflow is totally different now.

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Unlike individual tax payments — extensions, estimated tax, etc. — for business payments you will need to log in to MyTax Illinois, using the same credentials you usually use for paying sales tax or monitoring state payroll taxes.

On the main page, you should see a list of all your accounts with IDOR & IDES, something like this:

Click on the “Business” link. You will see a list of periods.

Click on the period for which you want to make the payment. It is very important to pick the correct period. Keep in mind this is usually the prior year’s ending date, if you’re trying to pay income tax (aka “business replacement tax”) for a return or an extension. You would choose the current year’s ending date if you are trying to make a quarterly estimated tax payment for your business.

Then click “Make a Payment” in the upper-right corner of this portion of the screen, under “I Want To”.

Then click “Bank Account Debit”.

That link will take you to a page where you will select a payment type. It is very important that you select the correct payment type.

They changed the forms a couple of years ago so that there’s no separate extension tax payment form — you just make a payment under the type of income tax form that your business usually files.

For example, a partnership or multi-member LLC would usually select IL-1065 payment — whereas an S-Corp would file an IL-1120-ST. Confirm that you are selecting the correct type that corresponds with your annual business tax return.

It will prompt you to enter your payment information.

And then click Submit. Make sure to save or print the confirmation page that pops up as a pdf — for your files, but also please send it along to your amazing and dedicated tax preparer.

(If you miss that last bit, then please go into your payment history for this account and do a print-screen that includes the status section; it will show the amount, confirmation number, and date/time.)

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