Partnerships. File a 2019 calendar year return (Form 1065). Provide each partner with a copy of their Schedule K-1 (Form 1065), Partner’s Share of Income, Deductions, Credits, etc., or substitute Schedule K-1 (Form 1065).

To request an automatic 6-month extension of time to file the return, file Form 7004. Then file the return and provide each partner with a copy of their final or amended (if required) Schedule K-1 (Form 1065) by September 15.

S corporations. File a 2019 calendar year  income tax return (Form 1120-S) and pay any tax due. Provide each shareholder with a copy of their Schedule K-1 (Form 1120-S), Shareholder’s Share of Income, Deductions,
Credits, etc., or substitute Schedule K-1 (Form 1120-S).
To request an automatic 6-month extension of time to file the return, file Form 7004 and deposit what you estimate you owe in tax. Then file the return; pay any tax, interest, and penalties due; and provide each  shareholder with a copy of their Schedule K-1 (Form 1120-S) by
September 15.

S corporation election. File Form 2553 to elect to be treated as an S corporation beginning with calendar year 2020. If Form 2553 is filed late, S corporation treatment will begin with calendar year 2021.