What IRS Form 1120 (2024) Is For

IRS Form 1120 is the U.S. Corporation Income Tax Return that all domestic C corporations must file annually to report their income, deductions, credits, and calculate federal income tax liability (IRS Instructions for Form 1120 (2024)). This includes corporations in bankruptcy and entities that elected to be treated as corporations for tax purposes.

When You’d Use Form 1120 for 2024 (Late or Amended Filing)

You’d file a late 2024 Form 1120 if you missed the original deadline (generally April 15, 2025 for calendar-year corporations, or September 15, 2025 for fiscal year corporations ending June 30). Common cases include IRS notices demanding the return, discovering tax owed, or establishing losses. For amendments, file Form 1120-X to correct errors or claim adjustments.

Key Rules Specific to 2024

• Late filing penalty: Minimum penalty increased to $510 if filed more than 60 days late.
  
  
• Mandatory e-filing: Corporations filing 10+ returns annually in 2025 must e-file Form 1120 unless exceptions apply.
  
  
• CAMT penalty relief: IRS Notice 2024-66 provided relief for Corporate Alternative Minimum Tax estimated payments.
  
  
• Updated DRD worksheet: Dividends-received deduction worksheet revised for section 250 impacts.
  
  

Step-by-Step (High Level)

1. Gather your records: Request IRS tax transcripts and assemble books, financials, and prior returns.
   
   
2. Use correct-year form: Complete the 2024 Form 1120 or Form 1120-X for amendments.
   
   
3. Attach schedules: Include M-1, M-2, or M-3 if assets exceed $10 million, plus any applicable dividend or related party schedules.
   
   
4. File return: E-file if required, otherwise mail to the IRS address listed for your location.
   
   
5. Keep copies: Retain all filed returns and supporting documentation for at least three years.
   
   

Common Mistakes and How to Avoid Them

• Missing the NOL election deadline to waive carryback, which cannot be changed later.
  
  
• Incorrectly calculating NOL deductions under pre-2018 and post-2017 rules.
  
  
• Forgetting Schedule M-3 for corporations with $10M+ in assets.
  
  
• Confusing fiscal year deadlines, particularly for June 30 year-ends.
  
  
• Poor documentation of related party transactions on Schedule K.
  
  
• Submitting paper returns despite mandatory e-filing requirements.
  
  

What Happens After You File

The IRS processes e-filed returns in 2–3 weeks and paper returns in 6–8 weeks. You may receive notices requesting clarification, additional information, or adjustments. If you owe, payment plans are available through Form 9465 or IRS.gov. Interest and penalties accrue on unpaid balances. The IRS generally has three years to audit, or six years if significant income is omitted.

FAQs

How long do I have to file a late 2024 return?

There’s no absolute deadline for filing a late return, but penalties and interest accrue until filed. The failure-to-file penalty alone is 5% per month of unpaid tax. Filing sooner stops penalties from compounding and reduces overall costs, even if you can’t pay in full immediately.

What penalties will I face for filing late?

The IRS charges a 5% penalty per month on unpaid tax, capped at 25%. If more than 60 days late, a minimum $510 penalty applies regardless of balance due. Late payment penalties add 0.5% per month, also capped at 25%. Interest accrues on all unpaid tax until satisfied.

Can I get my tax transcripts before filing?

Yes, request transcripts online at IRS.gov or by calling 1-800-908-9946. These transcripts show reported income, payments, and any IRS adjustments. Reviewing them before filing ensures accuracy, avoids duplicate reporting, and helps identify missing returns. Allow 2–3 weeks for electronic updates or longer if requesting mailed transcripts.

How far back can I claim refunds on amended returns?

Refunds can generally be claimed within three years of the original due date or two years from when the tax was paid, whichever is later. For a 2024 return due April 15, 2025, refund claims must be filed by April 15, 2028, unless extensions or special circumstances apply.

Do I need to amend state returns too?

Most states require filing amended returns if your federal return is amended. State rules vary on timing, but many require amendments within 180 days of federal changes. Check your state’s tax agency website to confirm deadlines, forms, and whether penalties or interest apply for late state amendments.

Can I still make elections on an amended return?

Some elections, such as depreciation method changes, can be made on amended returns within six months of the original due date. Others, like the net operating loss carryback waiver, must be made on the original timely filed return and cannot be changed afterward. Review instructions for election-specific rules.

What if I can’t pay the full amount owed?

The IRS offers installment agreements through Form 9465 or online applications. Depending on the balance, you may qualify for streamlined plans up to 72 months. For severe hardship, you may request an Offer in Compromise to settle for less. Interest and penalties continue while balances remain unpaid.

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