C-Corporation Estimated Tax Payments and Deadlines

When a C-Corporation Must Make Estimated Tax Payments

A C-Corporation must make estimated tax payments if it expects to owe $500 or more in federal income tax for the taxable year.

If a corporation does not pay enough estimated tax, or fails to pay on time, the IRS may assess penalties and interest.

C-Corporations generally make estimated payments through the Electronic Federal Tax Payment System (EFTPS), which is also used for payroll and excise tax deposits.

💡 New for 2025: Corporations will also be able to make payments using IRS Direct Pay for Businesses.

C-Corporation Estimated Tax Due Dates

Estimated tax payments are due quarterly — on the 15th day of the fourth, sixth, ninth, and twelfth months of the corporation’s tax year.

For calendar-year corporations, the due dates are:

• 1st Payment: April 15
  
  

• 2nd Payment: June 15
  
  

• 3rd Payment: September 15
  
  

• 4th Payment: December 15
  
  

⚠️ Note: The fourth corporate payment is due in December, not January 15 like it is for individuals.

How to Calculate Estimated Tax Payments

Each quarterly payment generally equals 25% of the corporation’s required annual payment, which is the lesser of:

1. Current Year Method: 100% of the federal income tax expected for the current year, or
   
   

2. Prior-Year Safe Harbor: 100% of the federal income tax shown on the prior year’s return.
   
   

If a corporation later determines that its estimated tax was too low, it should recalculate and make a catch-up payment immediately to reduce penalties for earlier underpayments.

Safe Harbor Rules and Exceptions

A C-Corporation may avoid underpayment penalties if:

• The total tax due is less than $500, or
  
  

• Each quarterly payment equals at least 25% of either:
  
  

  • The current year’s tax liability, or
    
    

  • The prior year’s tax liability.
    
    

However, corporations cannot use the prior-year safe harbor if:

• The prior year was a short tax year (less than 12 months),
  
  

• The corporation did not file a return for the prior year, or
  
  

• The corporation had $1 million or more in modified taxable income in any of the last three years.
  
  

In these high-income cases, the first estimated payment may still be based on 25% of the previous year’s tax liability, but later payments must reflect current-year income.

Penalties for Underpayment

The IRS may assess a non-deductible penalty if required quarterly payments are not made in full or on time. The penalty is based on the amount underpaid and the length of the delay.

Making timely and accurate estimated payments helps corporations avoid costly interest and penalties.

Expert Help with C-Corporation Tax Compliance

At Z-Tax & Accounting, we provide professional guidance and full-service support for:

• C-Corporation formation and setup
  
  

• Quarterly and annual tax compliance
  
  

• Estimated tax calculations and payments
  
  

• IRS Form 1120 preparation and filing
  
  

• Penalty prevention and resolution
  
  

Our experienced professionals help you stay compliant with all federal, state, and local tax laws — while ensuring your C-Corporation meets every filing and payment deadline.

📞 Contact Z-Tax & Accounting today to get expert help with your C-Corporation estimated tax payments, filings, and compliance throughout the year.

Related Topics for C Corporations:           Inentory Methods for C Corporations          C Corporation Accumulated Earnings & its Tax Condequences          C Corporation Filing Requirements          C Corporation Extension to file and non-filing penalties for Timely filing a return          C Corporation Estimated Tax Payments and Due Dates          C Corporation Amdended Tax Returns & Corporate Refunds          C Corporation Double Taxation & Corporate Alternative Minimum Tax (CAMT)          Contribution to Capital to a C Corporation in exchange for Stock          How to complete Form 1120, C-Corporation income tax return line by line          C Corporation Form 1120 Guide | Book-to-Tax Reconciliation & Schedules          Contribution of Capital to a C Corporation (C-Corp) in exchange for Stock

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