Individuals, Partnerships, Trusts and LLCs filing as partnerships

The return is due on the 15th day of the 4th month after the end of the tax year. For calendar year tax payers this is April 15th.

Corporations and LLCs filing as associations

The return is due on the 15th day of the 3th month after the end of the tax year. For calendar year tax payers this is March 15th.

Exempt organizations

For most exempt organizations, Form 990-T is due annually by the 15th day of the 5th month after the end of the tax year.

Estates

Nine months after the date of death.

Gift tax returns

April 15th following the year in which the gift is made.

If the due date falls on a Saturday, Sunday, or legal holiday, the due date is the next business day.