File a 2012 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 2013. If Form 2553 is filed late, S treatment will begin with calendar year 2014.
File a 2012 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.
December 10 (Employees who work for tips)
If you received $20 or more in tips during November, report them to your employer - Details
December 16 (Corporations)
Deposit the fourth installment of estimated income tax for 2013 - Details
December 25 (Everyone)
Federal Holiday (Christmas Day) - Details