Do not request an extension to file. All corporations are granted an automatic sevenmonth extension to file Form M4, Corporation Franchise Tax Return.Extended Deadline with Minnesota Tax Extension: Minnesota offers a 6-month extension, which moves the individual filing deadline from April 15 to October 15. You can only eFile and IRS tax extension, but not a Minnesota extension. The tax extension will only avoid late filing penalties until the October deadline. A Minnesota personal extension will give you 6 more months to file your return, moving the deadline to October 15 (for calendar year filers). Minnesotans automatically have until Oct. 15 to file state taxes before charging late fees. You'll receive an electronic acknowledgment once you. Minnesota allows an automatic extension to October 15 without a written application.