Essential December 2025 Tax Deadlines for Businesses

December is a pivotal month for businesses to ensure tax compliance and wrap up year-end responsibilities. Key tax deadlines, such as corporate estimated tax payments and monthly payroll tax deposits, demand attention to avoid penalties. As the year-end approaches, it's critical to finalize any financial transactions before December 31, due to potential closures.

December 15 - Corporate Estimated Taxes

The deadline for the fourth installment of estimated tax payments for calendar year corporations is December 15, 2025. Ensuring accurate calculations and timely payments is essential to remain compliant.

Image 1

December 15 - Employer Deposits

If your business operates under monthly deposit rules, December 15 is the deadline for submitting Social Security, Medicare, and withheld income tax for the prior month. This date is also applicable to nonpayroll withholding deposits, adhering to the monthly deposit schedule.

Image 3

December 31 - Year-End Transactions

December 31 marks the final business day to complete year-end financial actions. Be proactive in arranging transactions beforehand, as many institutions may close early. Delaying until the last day might complicate your financial strategy.

Weekends & Holidays:

If a tax due date falls on a weekend or legal holiday, it automatically extends to the next business day that isn't a holiday, ensuring no penalties for such timing issues.

Image 2

Disaster Area Extensions:

Should your business be located in a designated disaster area, deadline extensions may apply. For guidance on current disaster designations and filing extensions, consult these resources:

Share this article...

Want tax & accounting tips and insights?

Sign up for our newsletter.

I confirm this is a service inquiry and not an advertising message or solicitation. By clicking “Submit”, I acknowledge and agree to the creation of an account and to the and .