Skip to main content
Sign Up For Updates

Who must file Form IL-1065 and when is its due date?

You must file Form IL-1065, Partnership Replacement Tax Return, if you are a partnership, as defined in "Definitions to help you complete your Form IL-1065" in the Form IL-1065 instructions, and you have base income or loss as defined under the Illinois Income Tax Act (IITA) allocable to Illinois. If you are a partnership organized for the sole purpose of playing the Illinois State Lottery, you are not required to file a Form IL-1065.

You are required to report and pay pass-through withholding on behalf of your nonresident partners if they have not provided Form IL-1000-E, Certificate of Exemption for Pass-through Withholding, to you. Individuals cannot claim the exemption from pass-through withholding by filing Form IL-1000-E. You may elect to pay pass-through entity tax to provide a credit for your partners for tax years ending on or after December 31, 2021, and beginning before January 1, 2026.

Note: For tax years ending on or after December 31, 2023, any partnership that qualifies as an “investment partnership” as defined in the IITA Section 1501(a)(11.5)(A-5) is required to withhold for their nonresident partners the partner’s share of partnership income from another lower-tier partnership that is apportionable or allocable to Illinois by the investment partnership. Investment partnerships with nonresident partners must file a Form IL-1065 to report investment partnership withholding. See the Form IL-1065 instructions for more information.

In general, Form IL-1065 is due on or before the 15th day of the 4th month following the close of the taxable year. We grant you an automatic six-month extension of time to file your partnership tax return. 

See our Partnership web page for more information.

If you have additional inquiries, you may submit them on the Questions, Comments, or Requests form.