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Here are some of the key tax-related deadlines affecting businesses and other employers during the fourth quarter of 2018.

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.

  • October 15 – If a calendar-year C corporation that filed an a utomatic six-month extension: File a 2017 income tax return (Form 1120) and pay any tax, interest and penalties due. Make contributions for 2017 to certain employer-sponsored retirement plans.
  • October 31 – Report income tax withholding and FICA taxes for third quarter 2018 (Form 941) and pay any tax due. (See exception below under “November 13.”)
  • November 13 – Report income tax withholding and FICA taxes for third quarter 2018 (Form 941), if you deposited on time and in full all of the associated taxes due.
  • December 17 – If a calendar-year C corporation, pay the fourth installment of 2018 estimated income taxes. © 2018