Partnership Due Dates

​If you file by calendar year, your tax return (Form M3, Partnership Return) and payment are due by March 15 of the following year.

If you file by fiscal year, the due date is the 15th day of the third month after the end of your tax year.

When the due date is on a weekend or legal holiday, returns and payments must be postmarked or electronically transmitted on or by the next business day.