March 1

Farmers and Fishermen – File your 2018 income tax return (Form 1040) and pay any tax due. However, you have until April 15 (April 17 if you live in Maine or Massachusetts) to file if you paid your 2018 estimated tax by January 15, 2019.

March 11

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.

Partnerships – File a 2018 calendar year income tax return (Form 1065). Provide each partner with a copy of their Schedule K-1 (Form 1065-B) or substitute Schedule K-1. 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 K­1 (Form 1065) by September 16.

S Corporations – 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, 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 in tax.

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 2019. If Form 2553 is filed late, S corporation treatment will begin with calendar year 2020.

April 1

Electronic Filing of Forms – File Forms 1097, 1098, 1099 (except Form 1099-MISC), 3921, 3922, and W-2G with the IRS. This due date applies only if you file electronically. The due date for giving the recipient these forms generally remains January 31.

Electronic Filing of Form W-2G – File copies of all the Form W-2G (Certain Gambling Winnings) you issued for 2018. This due date applies only if you electronically file. The due date for giving the recipient these forms remains January 31.

Electronic Filing of Forms 8027 – File copies of all the Forms 8027 you issued for 2018. This due date applies only if you electronically file. Otherwise, see February 28.

Electronic Filing of Forms 1094-C and 1095-C and Forms 1094-B and 1095-B – If you’re an Applicable Large Employer, file electronic forms 1094-C and 1095-C with the IRS. For all other providers of minimum essential coverage, file electronic Forms 1094-B and 1095-B with the IRS.