When To File

Generally, a domestic partnership must file Form 1065 by the 15th day of the 3rd month following the date its tax year ended as shown at the top of Form 1065. For calendar-year partnerships, the due date is March 15.

If the due date falls on a Saturday, Sunday, or legal holiday in the District of Columbia or the state in which you file your return, a return filed by the next day that isn’t a Saturday, Sunday, or legal holiday will be treated as timely. Calendar-year partnerships may therefore timely file their returns for the 2025 partnership year by March 16, 2026.

Private Delivery Services (PDSs) Partnerships can use certain PDSs designated by the IRS to meet the “timely mailing as timely filing/paying” rule for tax returns. Go to IRS.gov/PDS for the current list of designated services. The PDS can tell you how to get written proof of the mail date.

For the IRS mailing address to use if you’re using a PDS, go to IRS.gov/PDSStreetAddresses .

Caution: A PDS can’t deliver items to P.O. boxes. You must use the U.S. Postal Service to mail any item to an IRS P.O. box address.

Extension of Time To File File Form 7004, Application for Automatic Extension of Time To File Certain Business Income Tax, Information, and Other Returns, to request an extension of time to file. File Form 7004 by the regular due date of the partnership return. Form 7004 can be electronically filed. See the Instructions for Form 7004.

Period Covered The 2025 Form 1065 is an information return for calendar year 2025 and fiscal years that begin in 2025 and end in 2026. For a fiscal year or a short tax year, fill in the tax year space at the top of Form 1065 and each Schedule K-1 or K-3, if applicable.

Instructions for Form 1065 (2025) 5