All corporations are granted an automatic sevenmonth extension to file Form M4, Corporation Franchise Tax Return. You automatically have until October 15 to file before we charge a late filing penalty.Do not request an extension to file. The extension of time to file is NOT an extension of time for payment of tax. The state of Minnesota doesn't require any extension Form as it automatically grants extensions up to 6 months. Extended Deadline with Minnesota Tax Extension: Minnesota offers a 6-month extension, which moves the individual filing deadline from April 15 to October 15. A Minnesota personal extension will give you 6 more months to file your return, moving the deadline to October 15 (for calendar year filers). Minnesota allows an automatic extension to October 15 without a written application. License may request one time-limited extension. PENALTYucator - Late Filing, Payment Penalties?