January  

16 – Fourth quarter 2023 estimated tax due. Use Form 1040-ES.
31 – Deadline for employers to provide copies of Forms W-2 and 1099 for 2023 to employees.

February

15 – If you claimed exemption from income tax withholding last year on the Form W-4 you gave your employer, you must file a new Form W-4 by February 15 to continue your exemption for another year.

March

1 – Deadline for farmers and fishermen who have a balance due on their taxes to file their 2023 individual income tax returns and pay the balance due without penalties.

15 – Deadline for 2023 S corporation tax returns (Form 1120-S) or to request an extension using Form 7004.

15 – Deadline to file 2023 partnership tax returns (Form 1065) or to request an automatic extension (Form 7004).

April

15 – Deadline to file 2023 individual income tax returns (Form 1040) and any taxes owed, or to file for an automatic 6-month extension.

15 – Last day to contribute to a traditional IRA, Roth IRA, or SEP-IRA for the 2023 tax year.

15 – First quarter 2024 estimated tax due. Use Form 1040-ES.

15 – Deadline to file 2023 trust tax returns (Form 1041) or to request an automatic extension.

15 – Deadline to file 2023 corporate tax returns (Form 1120) or to request an automatic extension (Form 7004).

June

17 – Deadline for U.S. citizens living abroad to file individual tax returns and pay any tax, interest, and penalties due, or to request a 4-month extension (Form 4868).

17 – Second quarter 2024 estimated tax due. Use Form 1040-ES.

September

16 – Third quarter 2024 estimated tax due. Use Form 1040-ES.

16 – Final deadline to file 2023 partnership tax return if you were given a 6-month extension.

16 – Final deadline to file 2023 S corporation tax return if you were given a 6-month extension.

October

1 – Deadline for existing employers to establish a SIMPLE IRA plan.

15 – If you were given a 6-month extension to file your income tax return for 2023, file Form 1040 and pay any tax, interest, and penalties due.

15 – Final deadline to file 2023 corporate tax return if were given a 6-month extension.

Source: Internal Revenue Service, 2023