2023 Q4 Tax Calendar: Key Deadlines for Businesses & Other Employers


Tax Due Dates for 4th Quarter of 2023Here are some of the key tax-related deadlines affecting businesses and other employers during the fourth quarter of 2023. Keep in mind that this list isn’t all-inclusive, so there may be additional deadlines that apply to you. Contact us to ensure you’re meeting all applicable deadlines and to learn more about the filing requirements.

Note: There may be a postponement of certain tax-filing and tax-payment deadlines for taxpayers who reside in or have businesses in federally declared disaster areas.

Monday, October 2

The last day you can initially set up a SIMPLE IRA plan, provided you (or any predecessor employer) didn’t previously maintain a SIMPLE IRA plan. If you’re a new employer that comes into existence after October 1 of the year, you can establish a SIMPLE IRA plan as soon as administratively feasible after your business comes into existence. Learn more about the best retirement plans for small business.

Monday, October 16

If a calendar-year C corporation that filed an automatic six-month extension:

    • File a 2022 income tax return (Form 1120) and pay any tax, interest and penalties due.
    • Make contributions for 2022 to certain employer-sponsored retirement plans.
    • Establish and contribute to a SEP for 2022, if there was a filing for an automatic six-month extension.

Tuesday, October 31

Report income tax withholding and FICA taxes for third quarter 2023 (Form 941) and pay any tax due. (See exception below under “November 13.”)

Monday, November 13

Report income tax withholding and FICA taxes for third quarter 2023 (Form 941), if you deposited on time (and in full) all of the associated taxes due.

Friday, December 15

If a calendar-year C corporation, pay the fourth installment of 2023 estimated income taxes.

Contact us if you’d like more information about the filing requirements and to ensure you’re meeting all applicable deadlines.