2025
January 15
- Fourth quarter installment for 2024 estimated income tax is due for calendar year-end taxpayers.
April 15
- First quarter installment for 2025 estimated income tax is due for calendar year-end taxpayers.
- Form 40 corporation income tax return and tax are due for 2024 calendar year-end taxpayers (Note: This date does not apply to a corporation that is a tax-exempt entity or cooperative. See May 15 and September 16).
May 15
- Form 40 corporation income tax return and tax are due for 2024 calendar year-end tax-exempt organizations that are required to report unrelated business taxable income.
June 16
- Important Note: Because June 15 falls on a Saturday, any return, tax payment, estimated payment, or other required action is not due until Monday, June 16.
- Second quarter installment for 2025 estimated income tax is due for calendar year-end taxpayers.
September 15
- Third quarter installment for 2025 estimated income tax is due for calendar year-end taxpayers.
- Form 40 corporation income tax return and tax are due for 2024 calendar year-end cooperatives.
November 17
- Important Note: Because November 15 falls on a Saturday, any return, tax payment, estimated payment, or other required action is not due until Monday, November 17.
- Form 40 corporation income tax return is due for 2024 calendar year-end taxpayers with a federal extension.
December 15
- Form 40 corporation income tax return is due for 2024 calendar year-end tax-exempt organizations with a federal extension that are required to report unrelated business taxable income.