Essential October 2025 Tax Deadlines for Businesses

As the crisp autumn air arrives this October, businesses must gear up for critical tax filing deadlines. From corporate taxes to payroll deposits and retirement plans, staying on top of these dates is crucial to ensure compliance and avoid unnecessary penalties.

October 15 - Corporate Tax Filings

The deadline for filing the 2024 calendar year income tax return (Form 1120) is October 15. This is applicable only if an automatic 6-month extension was requested by April 15. Make sure all taxes, including interest and penalties, are settled by this date.

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October 15 - Payroll Tax Deposits

If the monthly deposit rule applies, employers must deposit Social Security, Medicare, and withheld income tax for September by October 15. This also applies to nonpayroll withholding deposits for September.

October 15 - Set-Up and Contribution Deadlines for Retirement Plans

For those with an extension, October 15 is the last opportunity to establish a Keogh retirement account if you plan to contribute for the year 2024. Likewise, contributions to SEP IRA and Keogh plans for 2024 must be completed by this date if you are relying on an extension.

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October 31 - Filing and Deposit Requirements for Employers

Employers must file Form 941 for the third quarter of 2025 and handle any undeposited taxes due under the accuracy of deposit rules by October 31. Notably, if your tax liability is under $2,500, you can include the payment with your return. Those having fully deposited taxes timely can file by November 10.

Small employers must note any outstanding tax obligations, especially if the annual tax liability exceeds $2,500 but is less than $2,500 for the quarter. Also, federal unemployment taxes (FUTA) owe surpassing $500 until September become due.

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Considerations for Weekends, Holidays, and Disasters

If any due date lands on a weekend or legal holiday, it is pushed to the next business day not designated as a holiday. Similarly, extensions are granted for recognized disaster areas, offering some relief to affected regions. Consult resources such as FEMA and the IRS for updates and disaster area declarations.

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