Key Business Tax Deadlines for October 2025

October brings in the crisp air of fall and a series of crucial business tax deadlines that cannot be overlooked. From corporate tax filings to payroll deposits, staying on top of these critical dates is essential to ensure compliance and avoid any penalties.

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October 15 - Corporate Tax Filings
Calendar year corporations need to file their 2024 income tax return using Form 1120 and remit any taxes, interests, or penalties owed. This deadline holds if an automatic six-month extension was filed by April 15.

October 15 - Payroll Tax Deposits
Employers adhering to the monthly deposit rule must deposit Social Security, Medicare, and withheld income tax for September 2025 by this date. The same deadline applies for nonpayroll withholding deposits where the monthly deposit rule is relevant.

October 15 - Retirement Planning for Self-Employed
Self-employed individuals who have extended their 2023-2024 tax returns until October 15, 2025, need to establish a Keogh Retirement Account for contributions for 2024 by this date.

October 15 - SEP and Keogh Contributions
For those with extensions through October 15, this is the last opportunity to contribute to SEP or Keogh retirement plans for the calendar year 2024.

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October 31 - Quarterly Payroll Reporting
File Form 941 for the third quarter of 2025 and ensure any undeposited tax is paid under deposit rules. If your tax liability is under $2,500, it can accompany a timely-filed return. Full deposits on time extend filing until November 10.

October 31 - Small Employer Obligations
Submit any undeposited tax where the liability exceeds $2,500 for the year but is less than $2,500 for the third quarter.

October 31 - Federal Unemployment Tax
Deposit Federal Unemployment Tax for amounts exceeding $500 accumulated through September.

Handling Weekends & Holidays:
Should a deadline fall on a weekend or public holiday, it automatically extends to the next business day that's not a holiday.

Disaster Area Extensions:
In disaster-designated regions, filing deadlines extend accordingly. Refer to official sites for updates:
FEMA and IRS.

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If any of these topics caught your attention, please contact to start the conversation!
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