Some business entities’ income tax returns have due dates other than April 15. The instructions for each type of form note the appropriate due date:

• A sole proprietor’s Schedule C (Form 1040), Profit or Loss From Business (Sole Proprietorship) and an individual farmer’s Schedule F (Form 1040), Profit or Loss From Farming are attached to Form 1040, U.S. Individual Income Tax Return or Form 1040-SR, U.S. Tax Return for Seniors. Therefore, the due date is the 15th day of the fourth month following the end of the tax year. This date is April 15 for calendar year taxpayers.
• Most partnerships use the calendar year, but other tax years are permitted. The partnership tax return is generally due by the 15th day of the third month following the end of the tax year. See the Instructions for Form 1065, U.S. Return of Partnership Income.
• Most S corporations use the calendar year, but other tax years are permitted. The due date is the 15th day of the third month following the end of the tax year. See the Instructions for Form 1120-S, U.S. Income Tax Return for an S Corporation.
• A corporation that’s not an S corporation may use either the calendar year or a fiscal tax year. The corporate tax return is generally due by the 15th day of the fourth month following the end of the corporation’s tax year. However, a corporation with a fiscal tax year ending June 30 must file by the 15th day of the third month after the end of its tax year. See the Instructions for Form 1120, U.S. Corporation Income Tax Return for due dates and exceptions to due dates.