The due date for the calendar year Form 1065 (Partnerships), Form 1041 (Estate and Trusts), and Form 1120S (S corporation) returns is March 16, 2020. The due date for fiscal year Form 1065 and Form 1041 is the 15th day of the third month following the close of the tax year. By filing Form 7004, Application for Automatic Extension of Time to File Certain Business Income Tax, Information, and Other Returns, the extended due date for Form 1065, Form 1041, and Form 1120S is September 15, 2020.
For a calendar-year C corporation, the due date for form 1120 is April 15, 2020. The due date for a fiscal year C corporation is the 15th day of the fourth month following the close of the corporation’s year. By filing Form 7004, the C corporation can get an automatic six-month extension, and the extended due date is October 15, 2020.