Skip to content

2021 Q4 tax calendar: Key deadlines for businesses and other employers

Here are some of the key tax-related deadlines affecting businesses and other employers during the fourth quarter of 2021. 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: Certain tax-filing and tax-payment deadlines may be postponed for taxpayers who reside in or have a business in federally declared disaster areas. 

Friday, October 15

  • If a calendar-year C corporation that filed an automatic six-month extension:
    • File a 2020 income tax return (Form 1120) and pay any tax, interest and penalties due.
    • Make contributions for 2020 to certain employer-sponsored retirement plans.

Monday, November 1

  • Report income tax withholding and FICA taxes for third quarter 2021 (Form 941) and pay any tax due. (See exception below under “November 10.”)

Wednesday, November 10

  • Report income tax withholding and FICA taxes for third quarter 2021 (Form 941), if you deposited on time (and in full) all of the associated taxes due.

Wednesday, December 15

  • If a calendar-year C corporation, pay the fourth installment of 2021 estimated income taxes.

Friday, December 31

  • Establish a retirement plan for 2021 (generally other than a SIMPLE, a Safe-Harbor 401(k) or a SEP).

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

© 2021


Emil Estafanous, CPA, CFF, CGMA