What IRS Form 1120 (2023) Is For

IRS Form 1120 is the U.S. Corporation Income Tax Return that domestic C corporations use to report income, gains, losses, deductions, and credits, and to calculate their federal income tax liability (IRS Instructions for Form 1120 (2023)). All domestic corporations must file unless they qualify for a special return or exemption, regardless of whether they owe tax.

When You’d Use Form 1120 for 2023 (Late or Amended Filing)

You would file a late 2023 Form 1120 if you missed the original deadline, generally April 15, 2024 for calendar-year corporations, or the 15th day of the 4th month after your fiscal year ends. Common reasons include IRS notices demanding the return, discovering you owe taxes, or claiming refunds. Refund claims follow strict statutory deadlines.

Key Rules Specific to 2023

• Corporate Alternative Minimum Tax (CAMT): Effective for large corporations with average annual adjusted financial statement income exceeding $1 billion.
  
  
• Business meals deduction: Reverted to 50% after temporary 100% rule expired.
  
  
• Failure-to-file penalty: Increased to $450 if over 60 days late.
  
  
• NOL rules: Limited to 80% of taxable income, carryforward indefinitely, no carryback.
  
  

Step-by-Step (High Level)

1. Gather tax transcripts: Request using Form 4506-T or online IRS tools.
   
   
2. Use correct-year form: Complete the 2023 Form 1120 with appropriate schedules.
   
   
3. Attach required schedules: Include Schedule D, M-1, M-2, or M-3 if assets exceed $10 million.
   
   
4. Calculate penalties and interest: Apply current IRS rates.
   
   
5. Submit return: E-file if required (10+ returns) or mail to IRS center.
   
   
6. Maintain records: Keep all documentation for at least three years.
   
   

Common Mistakes and How to Avoid Them

• Filing with the wrong year’s form instead of 2023.
  
  
• Omitting Schedules M-1 or M-2 when required.
  
  
• Miscalculating NOL deductions subject to 80% limit.
  
  
• Overlooking special fiscal-year deadlines.
  
  
• Failing to compute minimum late filing penalties.
  
  
• Neglecting state filing adjustments following federal amendments.
  
  

What Happens After You File

The IRS typically processes e-filed returns within 2–3 weeks and paper returns within 6–8 weeks. Notices may request more information or propose changes. If you owe taxes, you can request payment plans through Form 9465, with setup fees ranging from $22–$69. Refunds may be offset by other tax debts. Appeals are available for disputes.

FAQs

What’s the penalty for filing my 2023 Form 1120 late?

Late filing penalties are 5% of unpaid tax per month, up to 25%. Returns more than 60 days late face a minimum penalty of $450 or the tax due, whichever is smaller. Even corporations owing no tax may still incur this minimum penalty, so timely filing is critical for compliance.

Can I still get a refund if I file my 2023 return late?

Yes, but refund claims are time-barred if not filed within three years of the return’s original due date, or within two years of when tax was paid, whichever is later. For 2023 calendar-year corporations, refund claims must generally be filed by April 15, 2027, unless special circumstances extend deadlines.

Do I need to get transcripts before filing a late return?

It is highly recommended to obtain transcripts. Tax account transcripts from IRS.gov or via Form 4506-T provide details on what the IRS already has on file, such as payments, penalties, or substitute returns. This information helps prevent duplicate filings, ensures accuracy, and prepares you for potential penalty assessments before submitting a late return.

Should I amend my state return if I file an amended federal Form 1120?

Yes, in most cases. States often conform to federal changes, requiring amended returns when federal income or deductions change. Many states mandate filing within 180 days of a federal amendment. Always review your state’s specific requirements to avoid penalties, interest, or compliance issues resulting from inconsistent reporting across jurisdictions.

Can I e-file a late 2023 Form 1120?

Yes. Corporations filing 10 or more returns annually must e-file, while others may e-file voluntarily. E-filing is faster, reduces errors, and allows quicker IRS acknowledgment. Paper filing is permitted with approved hardship waivers. Using the IRS-approved electronic filing system is highly recommended, particularly for large or complex corporate returns requiring timely processing.

What if I discover errors after filing my late return?

File Form 1120X, Amended U.S. Corporation Income Tax Return, to correct mistakes. Include only corrected schedules and an explanation of changes. You generally have three years from the original return due date or two years from the tax payment date to amend. Accurate amendments reduce IRS delays and help maintain compliance.

How long will it take to process my late 2023 return?

E-filed returns usually process within 2–3 weeks, while paper returns take 6–8 weeks. However, complex or amended filings may undergo manual review, extending processing time significantly. IRS backlogs or additional inquiries can also delay completion. To minimize issues, ensure forms are accurate, schedules attached, and transcripts reviewed before submission.

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