Employers - Electronically file 2023 Form 1097, Form 1098, Form 1099 (other than those with an earlier deadline) and Form W-2G

Individuals - Report March tip income of $20 or more to employers (Form 4070).

Individuals - File a 2023 income tax return (Form 1040 or Form 1040-SR) or file for an automatic six-month extension (Form 4868). (Taxpayers who live outside the United States and Puerto Rico or serve in the military outside these two locations are allowed an automatic two-month extension without requesting an extension.) Pay any tax due.

Individuals - Pay the first installment of 2024 estimated taxes (Form 1040-ES) if not paying income tax through withholding or not paying sufficient income tax through withholding.

Individuals - Make 2023 contributions to a traditional IRA or Roth IRA (even if a 2023 income tax return extension is filed).

Individuals - Make 2023 contributions to a SEP or certain other retirement plans (unless a 2023 income tax return extension is filed).

Individuals - File a 2023 gift tax return (Form 709) or file for an automatic six-month extension (Form 8892). Pay any gift tax due. File for an automatic six-month extension (Form 4868) to extend both Form 1040 and Form 709 if no gift tax is due.

Household employers - File Schedule H, if wages paid equal $2,600 or more in 2023 and Form 1040 isn’t required to be filed. For those filing Form 1040, Schedule H is to be submitted with the return so is extended if the return is extended.

Calendar-year trusts and estates - File a 2023 income tax return (Form 1041) or file for an automatic five-and-a-half-month extension (Form 7004) (six-month extension for bankruptcy estates). Pay any income tax due.

Calendar-year corporations - File a 2023 income tax return (Form 1120) or file for an automatic six-month extension (Form 7004). Pay any tax due.

Calendar-year corporations - Pay the first installment of 2024 estimated income taxes, completing Form 1120-W for the corporation’s records.