An Overview of Illinois State Business Income Tax Extension Forms

- Updated Feb 27, 2021 - 8.00 AM by Admin, ExpressExtension

Does Illinois support tax extension for business tax returns?

Q

Yes. The state of Illinois supports the automatic extension of time to file business income tax returns with the State.

What Form does the state of Illinois require to apply for an extension?

Q

There is no state-specific form to request an extension, as the state of Illinois automatically provides the extension for up to 6 months for businesses to file an income tax return with the state.

How do I pay my balance due to the state of Illinois with my extension?

Q

You can choose to pay your balance due along with your return by using any one of the following options:

  • Electronic Payments through https://mytax.illinois.gov/
  • ACH Credit through https://mytax.illinois.gov/
  • Credit Card
  • Check or money order
    • Use Payment Voucher Form IL-1120-V - If your business is a Corporation
    • Use Payment Voucher Form IL-1120-ST-V - If your business is a Small Business Corporation
    • Use Payment Voucher Form IL-1065-V - If your business is a Partnership

When is the deadline to file a business tax return with Illinois?

Q
  • Businesses in Illinois (operating as Corporation) have to file their Form IL-1120 by the 15th day of the 4th month following the end of the accounting period.
  • Businesses in Illinois (operating as a partnership) have to file their Form IL-1065 by the 15th day of the 4th month following the end of the accounting period.

Where to mail payment Forms IL-1120-V, IL-1120-ST-V, & IL-1065-V?

Q

Mail Form IL-1065-V to the following address:

Illinois Department of Revenue,
P.O. Box 19053, Springfield,
IL 62794-9053

Mail Form IL-1120-V to the following address:

Illinois Department of Revenue,
P.O. Box 19038, Springfield,
IL 62794-9038

Mail Form IL-1120-ST-V to the following address:

Illinois Department of Revenue,
P.O. Box 19053, Springfield,
IL 62794-9053