Do I need to file my business, trust, or estate tax return if it shows a net loss?
If you are required to file an Illinois return (IL-1120, IL-1120-ST, IL-1065, or IL-1041), the return must be filed in a timely manner, regardless of net income or loss. If the loss return calculates an overpayment for which you expect to receive a refund or request a credit carry forward, you must file the loss return within 3 years of the extended due date of the loss return to receive a refund* or credit carry forward.
* A refund may be issued on returns filed more than 3 years past the extended due date if the payment that causes the overpayment was paid within one year of the refund request.
EXAMPLE: You claim a Net Loss Deduction on your December 2021 Form IL-1120. The loss you are claiming is from your December 2015 reporting period; however, you did not file your December 2015 Form IL-1120 until March 2021. Your December 2015 Form IL-1120 calculates a net loss and claims an overpayment from a payment made in 2015 which was applied to your December 2015 reporting period. You request the overpayment as a refund. The loss generated on your December 2015 return is available to be claimed on your December 2021 Form IL-1120; however, the refund claimed, due to the overpayment from the December 2015 reporting period, is unavailable to be refunded or applied toward a subsequent reporting period because your December 2015 return was filed more than three years from the extended due date of the original return.
See 86 Ill. Adm. Code Section 100.9410 for more information about limitations on claims for refunds.