March 10

Employees who work for tips – If you received $20 or more in tips during February, report them to your employer. You can use Form 4070.

March 15

Employers – Nonpayroll withholding. If the monthly deposit rule applies, deposit the tax for payments in February.

Employers – Social Security, Medicare, and withheld income tax. If the monthly deposit rule applies, deposit the tax for payments in February.

Corporations – File a 2015 calendar year income tax return (Form 1120) and pay any tax due. 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 Corporations – File a 2015 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, Credits, Deductions, 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.

Electing large partnerships – Provide each partner with a copy of Schedule K-1 (Form 1065-B), Partner’s Share of Income (Loss) From an Electing Large Partnership. This due date applies even if the partnership requests an extension of time to file the Form 7004.

S Corporation Election – File Form 2553, Election by a Small Business Corporation, to choose to be treated as an S corporation beginning with calendar year 2016. If Form 2553 is filed late, S treatment will begin with calendar year 2017.

Partnerships – File a 2015 calendar year return (Form 1065). Provide each partner with a copy of Schedule K-1 (Form 1065), Partner’s Share of Income, Credits, Deductions, etc., or a substitute Schedule K-1. If you want an automatic 5-month extension of time to file the return and provide Schedule K-1 or a substitute Schedule K-1, file Form 7004. Then file Form 1065 by August 15.

March 31

Electronic filing of Forms 1097, 1098, 1099, 3921, 3922, and W-2G – File Forms 1097, 1098, 1099, 3921, 3922, or W-2G with the IRS. This due date applies only. The due date for giving the recipient these forms generally remains February 1.

For information about filing Forms 1097, 1098, 1099, 3921, 3922, or W-2G electronically, see Publication 1220, Specifications for Electronic Filing of Forms 1097, 1098, 1099, 3921, 3922, 5498, and W-2G.

Electronic filing of Forms W-2 – File copies of all the Forms W-2 you issued for 2014. This due date applies only if you electronically file. Otherwise see February 29. The due date for giving the recipient these forms remains February 1.