Key Business Tax Deadlines: October 2025

October brings with it not only cooling fall temperatures but also crucial business tax deadlines. It's essential for business owners to be cognizant of these dates to maintain compliance and avoid potential penalties. From corporate tax returns to payroll deposits, stay ahead by marking these significant dates in your calendar.

October 15 - Corporate Tax Returns
If your corporation operates on a calendar year and you've filed for an automatic 6-month extension, now is the deadline to file your 2024 income tax return using Form 1120 and settle any outstanding tax, interest, or penalties.

October 15 - Payroll Taxes
Employers who comply with the monthly deposit rule should ensure that their deposits for Social Security, Medicare, and withheld income tax for September 2025 are made by this date. Nonpayroll withholdings for the same period are also due.

October 15 - Establishment of Keogh Accounts
Self-employed individuals looking to contribute to a Keogh Retirement Account for 2024 must establish their accounts by this deadline, granted there’s an extension from their 2024 tax return.

October 15 - SEP and Keogh Contributions
This is also the last opportunity to make contributions to SEP or Keogh retirement plans for the 2024 fiscal year if you are under extension.

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October 31 - Quarterly Payroll Reporting
File Form 941 for the third quarter of 2025. Any undeposited tax should be resolved following the accuracy of deposit rules. For liabilities under $2,500, you can remit payment via a timely filed return, and if taxes for the quarter were fully and punctually deposited, the filing deadline extends to November 10.

October 31 - Small Employer Deposits
For small employers with tax liabilities exceeding $2,500 for 2025 but under $2,500 for the third quarter, any outstanding tax must be deposited by this date.

October 31 - Federal Unemployment Tax
Businesses owing more than $500 in federal unemployment taxes up to September should make necessary deposits by this deadline.

Weekend and Holiday Adjustments:

Deadlines that fall on a weekend or legal holiday are automatically pushed to the next business day, ensuring taxpayers are not disadvantaged.

Disaster Area Extensions:

In designated disaster areas, tax deadlines are extended. To verify whether your area qualifies and to learn about the extended deadlines, visit the FEMA website and IRS announcement page.

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