File with the IRS if you’re an employer that will electronically file 2018 Form 1097, Form 1098, Form 1099 (other than those with an earlier deadline) and/or Form W-2G.
If your employees receive tips and you file electronically file Form 8027.
If you’re an Applicable Large Employer and filing electronically, file Forms 1094-C and 1095-C with the IRS. For all other providers of minimum essential coverage filing electronically, file Forms 1094-B and 1095-B with the IRS.
If you’re a calendar-year corporation, file a 2018 income tax return (Form 1120) or file for an automatic six-month extension (Form 7004) and pay any tax due.
Corporations pay the first installment of 2019 estimated income taxes.
Employers report income tax withholding and FICA taxes for the first quarter of 2019 (Form 941) and pay any tax due.
Employers report income tax withholding and FICA taxes for the first quarter of 2019 (Form 941) if you deposited on time and fully paid all of the associated taxes due.
Corporations pay the second installment of 2019 estimated income taxes.