Individuals: Filing a 2022 individual income tax return (Form 1040 or Form 1040-SR) or filing for a four-month extension (Form 4868), and paying any tax and interest due, if you live outside the United States or you serve in the military outside the United States and Puerto Rico.

Individuals: Paying the second installment of 2023 estimated taxes, if not paying income tax through withholding (Form 1040-ES).

Calendar-year corporations: Paying the second installment of 2023 estimated income taxes.