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Essential December 2025 Tax Deadlines for Small Businesses

As December rolls around, it's critical for business owners to keep an eye on important tax deadlines, particularly the due dates for corporate estimated tax payments and monthly payroll tax deposits. It's also a great time to ensure you complete all necessary year-end actions ahead of any closures on December 31.

December 15 - Corporations

The fourth installment of estimated tax for corporations operating on a 2025 calendar year is due. Be sure to mark this date to avoid any penalties.

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December 15 - Social Security, Medicare, and Withheld Income Tax

Employers who adhere to monthly deposit rules must make their deposits for Social Security, Medicare, and withheld income tax for November 2025 by this date. Additionally, it's the deadline for nonpayroll withholding deposits for November under the same rules.

December 31 - Last Day of the Year

Be proactive: if you need to complete financial actions, ensure they're finalized before the very last day of the year. Many institutions may close early, risking delays.

Weekends & Holidays:

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If a due date lands on a Saturday, Sunday, or legal holiday, it's automatically extended to the next business day that's not a holiday.

Disaster Area Extensions:

Special extensions are granted for areas declared as disaster zones. Stay informed by checking updates from these sources:

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Planning ahead with Bryant CPA LLC ensures no deadline is overlooked, allowing you to focus on closing out the year with peace of mind.

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