IRS Form 1120 (2019): U.S. Corporation Tax Return

What IRS Form 1120 (2019) Is For

IRS Form 1120 (2019) is the U.S. Corporation Income Tax Return used by domestic corporations to report income, gains, losses, deductions, and credits. It helps determine corporate income tax liability under the Internal Revenue Code. Unless exempt under section 501, every corporation generally must file this form each tax year, even if it has no taxable income. The form applies to both C corporations and certain transactions involving controlled foreign corporations or specified foreign financial assets.

Corporate taxpayers use this income tax return to pay taxes on income derived from business operations, report total assets, and disclose details of reportable transactions. Filing this form ensures compliance with federal tax obligations and tax law requirements.

When You’d Use Form 1120 for 2019 (Late or Amended Filing)

Corporations file a late or amended 2019 Form 1120 when they receive IRS notices about unfiled tax returns, discover errors, or need to claim missed deductions or credits. A corporation may also file if it failed to make estimated tax payments or wants to correct taxable income amounts.

Refund claims are still possible if submitted within three years of the original due date (April 15, 2020, for calendar-year filers) or within two years of payment, whichever is later. Businesses filing late should include payment for any unpaid federal income tax, excise tax, or other penalties to minimize interest. The IRS allows filing electronically through approved e-file providers or by mailing the paper form to the correct IRS center.

Key Rules Specific to 2019

• Net Operating Losses (NOLs): For the 2019 tax year, corporations could carry back NOLs for five years and carry them forward indefinitely, limited to a limitation of 80% of taxable income.
• Disaster Relief Contributions: Qualified charitable contributions for disaster relief made between December 31, 2017, and February 19, 2020, were not subject to the usual deduction limits under federal tax law.
• Penalty Updates: The minimum late filing penalty increased to $435 for returns due after 2019. Penalties apply if corporations fail to file by the due date or the extended due date without reasonable cause.

Browse more tax form instructions and filing guides in our Forms Hub.

Step-by-Step (High Level)

• Gather Tax Records and Transcripts: Request IRS transcripts through IRS.gov or Form 4506-T to confirm reported income, estimated tax payments, and prior balances.
• Use the Correct Tax Forms: Always complete the 2019 version of Form 1120. Using the wrong form year can delay processing and cause errors in tax liability calculations.
• Attach Required Schedules: Corporations with total assets exceeding $10 million must include Schedule M-3. Others generally attach Schedules M-1 and M-2 to reconcile net income and retained earnings.
• File and Pay Taxes: File by the fourth month after the end of your fiscal year, typically April 15 for calendar-year filers. Pay any outstanding tax balance to avoid interest or penalties.
• Maintain Records: Keep all supporting documents, including business deductions, credits, and tax forms, for a minimum of three years after the filing date. Retaining these helps address IRS inquiries or future audits.

Learn more about federal tax filing through our IRS Form Help Center.

Common Mistakes and How to Avoid Them

• Incomplete Forms: Fill in every line as instructed or write “N/A” when not applicable to prevent processing delays.
• Incorrect NOL Reporting: Verify year-specific NOL limits in IRS Publication 536 before filing to ensure accurate reporting.
• Missing Required Schedules: Review Form 1120 or 1120-S instructions to confirm that all necessary schedules are attached.
• Double Counting Deductions: Keep a clear record of deductions and credits to avoid reporting the same expense twice.
• Wrong Filing Dates: Check the correct due date for your fiscal or short tax year and file early or request an extension.
• Failure to Attach Properly: Assemble all forms and schedules in IRS order with clear labels to prevent delays.

Learn more about how to avoid business tax problems in our guide on How to File and Avoid Penalties.

What Happens After You File

After filing the corporation income tax return, the IRS typically processes it within several months. Late or amended returns may take longer to process. The corporation may receive IRS notices confirming acceptance, requesting more details, or proposing adjustments.

If the corporation owes taxes, interest, and penalties continue until payment is made. Payment options include check, electronic transfer, or an installment agreement using Form 9465. If the corporation disagrees with an IRS decision, it may appeal through the IRS Office of Appeals. A tax professional can help address disputes, determine reasonable cause for delays, and manage communications with the IRS.

FAQs

What is IRS Form 1120 (2019), and who must file it?

Domestic corporations use IRS Form 1120 (2019) to report income, deductions, and tax liability to the IRS. It applies to C corporations, S corporations that terminate, and foreign corporations with U.S. activities. Filing this federal tax return satisfies annual corporate income tax obligations under the Internal Revenue Code.

When are estimated tax payments due for corporations?

Corporations generally make four estimated tax payments throughout the tax year, due on the 15th day of the 4th, 6th, 9th, and 12th months of the fiscal year. Timely payment helps avoid penalties on underpaid estimated tax. Businesses should use prior-year income tax and deductions to calculate accurate estimates of their tax liabilities.

What if I missed the due date for my corporate income tax return?

If a corporation misses the original due date, it should file as soon as possible or request an extension of time to file. Late filings may result in other penalties and interest. Filing quickly and paying at least part of the federal tax due can reduce costs and demonstrate reasonable cause for delay.

Can I e-file my Form 1120 for the 2019 tax year?

Yes, many corporations can e-file late 2019 Form 1120 returns using IRS-approved software. E-filing ensures faster confirmation, reduced mailing costs, and fewer errors. However, amended returns (Form 1120-X) often require paper filing. Check with the IRS or your provider before submission.

How do corporate tax rules differ for a C corporation?

A C corporation pays federal income tax on its net income separately from its shareholders. These corporations are required to file Form 1120 annually to report business income, deductions, and credits. Certain transactions involving real property interests or foreign corporations may trigger additional reporting requirements.

For more resources on filing or understanding prior-year IRS forms, visit our guide on Business Income Tax Forms.