File a 2018 calendar year income tax return (Form 1120S) and pay any tax due. Provide each shareholder with a copy of Schedule K-1 (Form 1120S), Shareholder's Share of Income, Deductions, Credits, etc., or a substitute Schedule K-1. If you want an automatic 6-month extension of time to file the return, file Form 7004 and deposit what you estimate you owe.
S corporation election. File Form 2553, Election by a Small Business Corporation, to elect to be treated as an S corporation beginning with calendar year 2019. If Form 2553 is filed late, S treatment will begin with calendar year 2020.
File a 2018 calendar year income tax return (Form 1120S) and pay any tax due. This due date applies only if you timely requested an automatic 6-month extension. Otherwise, see March 15. Provide each shareholder with a copy of Schedule K-1 (Form 1120S) or a substitute Schedule K-1.
If you operate on a fiscal year, see tax calendar information for Fiscal-Year Taxpayers.
May 10 — Employees who work for tips
If you received $20 or more in tips during April, report them to your employer Details
May 10 — Social security, Medicare, and withheld income tax
File Form 941 for the first quarter of 2019. This due date applies only if you deposited the tax for the quarter timely, properly, and in full.
May 15 — Social security, Medicare, and withheld income tax
If the monthly deposit rule applies, deposit the tax for payments in April.
May 27 — Everyone
Federal Holiday (Memorial Day) Details