What is Form 1040-X: Amended Tax Return?

What is Form 1040-X?

IRS Form 1040-X is a tax form used by the Internal Revenue Service (IRS) to allow individuals to amend their tax returns. It is used to make changes or corrections to a previously filed tax return.

It is important to note that Form 1040-X can only be used to amend tax returns for the current tax year or for up to three prior tax years.

Any changes made to a tax return using Form 1040-X will affect the taxpayer's refund or balance due.

What are the benefits of filing Form 1040-X?

There are several benefits why a taxpayer may need to file Form 1040X. Some common reasons include:

• The taxpayer made a mistake on their original tax return, such as forgetting to include income, claiming an incorrect deduction or credit, or using the wrong filing status.
• The taxpayer received additional income or made additional payments after their original tax return was filed.
• The taxpayer received a corrected W-2 or 1099 form after their original tax return was filed.
• The taxpayer received a notice from the IRS indicating that their original tax return had errors or needed additional information.

How to file Form 1040-X

To file Form 1040-X, the taxpayer must first obtain a copy of their original tax return and any supporting documents. This may include W-2 forms, 1099 forms, or other documentation of income and deductions.

They will then need to fill out the form, explaining the changes they are making and the reasons for those changes. The form will also require the taxpayer to recalculate their tax liability based on the amended information.

There are also certain types of changes that cannot be made using Form 1040-X.

For example, Form 1040-X cannot be used to change the taxpayer's filing status from married filing jointly to married filing separately if the taxpayer is not eligible to file as married filing separately.

Additionally, Form 1040-X cannot be used to claim a tax credit or deduction that the taxpayer was not entitled to claim on their original tax return.

How to file Form 1040-X: A step-by-step guide

Filing Form 1040-X to amend your tax return involves a few critical steps.

Whether you’re correcting an error or adding overlooked information, here’s how to do it efficiently:

1. Determine if you need to amend your return.

• Amend your return if you need to correct your filing status, income, deductions, credits, or dependents.
• The IRS automatically corrects mathematical errors, so no amendment is needed in those cases.

2. Obtain Form 1040-X

Download Form 1040-X from or access it through tax software that supports e-filing.

Form 1040-X preview

 

3. Gather necessary documents

Locate your original return (Form 1040 or similar) and any new forms, schedules, or documentation supporting the amendment, such as corrected W-2s or 1099s.

4. Complete Form 1040-X

Personal Information:  Fill in your name, Social Security Number, and current address.

Tax Year: Specify the year of the return you’re amending.

Changes to Your Tax Return:

• Use the "Net Change" and "Correct Amount" columns to detail any adjustments to income, deductions, credits, or exemptions.
• Clearly explain the reason for the amendment in the Explanation Section (e.g., "Correcting income based on a late W-2").

Signature: Sign and date the form. If filing jointly, both spouses must sign.

5. Submit the amended return

• E-File: For the current tax year and the two prior tax years, you can file Form 1040-X electronically if using IRS-approved tax software.
• Mail: If e-filing isn’t available or you’re amending an older return, mail Form 1040-X to the address listed in the IRS instructions.

6. Include payment if taxes are owed

If your amended return results in additional taxes owed, include payment with Form 1040-X to avoid late payment penalties and interest.

7. Monitor the status of your amendment

Use the IRS "Where’s My Amended Return?" tool to track your filing status. Updates are available three weeks after submission and are refreshed daily.

Processing times:

• Amended returns typically take up to 16 weeks to process. However, during peak times or for complex amendments, it could take longer.
• If you filed by mail, the timeline may be extended due to mail handling delays.

Pro tip: If it's been over 16 weeks without an update, contact the IRS at 866-464-2050 for assistance.

Deadlines for filing Form 1040-X

The IRS imposes specific time limits for filing an amended return:

• Three-Year Rule: You have three years from the original filing deadline of your tax return (including extensions) to file Form 1040-X.
• Two-Year Rule: Alternatively, you can file within two years of the date you paid the tax, whichever is later.

For example: If you filed your 2021 tax return on April 15, 2022, and didn’t request an extension, the deadline to amend would be April 15, 2025.

Pro tip: Be mindful of these deadlines for each tax year you’re amending, especially if you’re amending multiple returns at once.

Common mistakes and pitfalls to avoid

Filing an amended return isn’t complicated, but small errors can cause delays or rejection. Here are common pitfalls and how to avoid them:

1. Incorrect calculations: Double-check all figures, especially the "Net Change" and "Correct Amount" columns on Form 1040-X. Use tax software or consult a professional if unsure.
2. Missing documentation: Attach all relevant supporting documents, such as revised W-2s, 1099s, or corrected schedules. Missing paperwork can result in processing delays.
3. Unclear explanations: The Explanation Section is your chance to tell the IRS what’s changed and why. Be concise but thorough – vague or incomplete explanations may lead to rejection.
4. Forgetting signatures: Sign and date your Form 1040-X before submission. If filing jointly, both spouses must sign.
5. Filing too soon after the original return: Wait until the IRS processes your original return before filing an amendment. Amending prematurely can cause unnecessary confusion.
6. Not accounting for state taxes: If your federal return changes, your state return may need to be amended too. Check with your state’s tax authority for requirements.

Pro tip: Filing electronically minimizes many common errors, as tax software flags potential issues before submission.