1040-X

Amended U.S. Individual Income Tax Return

Agency
IRS
Revision
Rev. December 2025
Fillable fields
166
Pages
2
Official source
IRS form page
Checked
October 14, 2026
Fill 1040-X online
Page 1 of form 1040-X

Form 1040-X: Amended U.S. Individual Income Tax Return

Form 1040-X is how you fix a federal income tax return after it has been filed. You use it to correct Form 1040, 1040-SR or 1040-NR, and the IRS page also lists older Forms 1040-A and 1040-EZ. It can change income, deductions, credits, filing status, dependents or payments.

The form works by comparison. For each line you change, you show the original amount, the change and the corrected amount, then explain why in plain words. The IRS reads the explanation to understand what you are asking it to do.

An amended return is not a new return. Wait until the original has been filed, and do not send a second original for the same year. The result may be a refund, a smaller or larger balance due, or no change in tax at all.

Page 1 of Form 1040-X, Amended U.S. Individual Income Tax Return, with its title area and the A, B and C columns

What's on Form 1040-X

Top section: who you are and which year

You enter your name, address, Social Security number and the tax year you are amending, along with your filing status for the original and amended return.

Columns A, B and C

Column A holds the original amounts or the amounts as previously adjusted. Column B is the net increase or decrease for each line you change. Column C is the corrected amount, which is column A plus or minus column B.

Income, deductions and tax lines

These run from adjusted gross income on line 1 through the standard or itemized deduction, taxable income and tax. The newer lines include the qualified business income deduction and deductions from Schedule 1-A.

Credits, payments and refund or amount you owe

Lines 12 through 17 cover withholding, estimated payments, earned income credit, refundable credits and payments made with an extension or the original return. Lines 18 through 23 show the overpayment, amount owed, refund and amount applied to next year's estimated tax.

Part I: Dependents

List every dependent claimed on the amended return, including those from the original return and anyone you add.

Part II: Explanation of changes

You say why you are amending. Attach a statement if you need more space.

Part III: Direct deposit

The instructions say this applies only to e-filed amended returns.

How to fill out Form 1040-X

  1. 1

    Start with a copy of your original return

    Keep it beside you. Column A comes from it or from IRS changes to it.

    Form 1040-X column A with the original amounts copied from the original return, sample values
  2. 2

    Fill in the heading

    Use the same name and Social Security number as the original, and mark the year you are amending.

    Heading of Form 1040-X with the same name and Social Security number as the original and the year marked, sample values
  3. 3

    Enter columns A, B and C only on changed lines

    Unchanged items carry over from column A. Show negative amounts in parentheses.

    Form 1040-X line with column A 5,000, column B (500) in parentheses and column C 4,500, sample values
  4. 4

    Show the tax method on line 6

    The instructions ask you to list the method used to figure the tax, such as the Tax Table.

    Form 1040-X line 6 with Tax Table written as the method used to figure tax
  5. 5

    Complete Part I if dependents changed

    List all dependents on the amended return, not only the new ones.

    Part I of Form 1040-X listing the original dependents and one newly added dependent, sample values
  6. 6

    Write the explanation in Part II

    Give the specific reason, for example that you received a corrected Form W-2 or that you changed your filing status. This free page lets you fill Form 1040-X in your browser.

    Part II of Form 1040-X saying a corrected Form W-2 was received, sample values
  7. 7

    Attach what changed

    Put a completed, updated Form 1040, 1040-SR or 1040-NR behind Form 1040-X on paper filings, with any schedules and forms that support the change. Do not attach the original return.

    Top of Form 1040-X telling you to attach a completed Form 1040 with your changes and supporting documents

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Deadlines, fees and where to send Form 1040-X

Time limit for a refund

For a refund or credit, the instructions generally say to file within 3 years of filing the original return, including extensions, or within 2 years of paying the tax, whichever is later. Some claims, such as bad debt or worthless securities, have longer limits.

E-file or mail

The IRS page says you can e-file an amended return with tax software for the current or two prior tax periods. On paper, mail to the address in any IRS notice you received. Otherwise use the service center for your state, with Austin for foreign addresses.

Signature

A paper return needs a handwritten signature. The instructions say digital or typed signatures are not valid on paper. Both spouses sign a joint return.

Processing time

The instructions say to allow 8 to 12 weeks, and up to 16 weeks in some cases. It can take up to 3 weeks before the return shows in the system. You can track it with Where's My Amended Return.

Common mistakes

Sending a second original return, leaving out the updated return and supporting schedules, skipping the explanation and forgetting to sign are the problems the instructions warn about.

Related forms

Who needs Form 1040-X?

  • People who found a mistake

    Use it if you left out income, claimed the wrong deduction or credit, entered the wrong filing status or dependents, or found an error after you filed. The IRS page says it can also be used to make certain elections after the deadline.

  • People who received a corrected form

    A corrected Form W-2 or 1099 that changes your numbers is a typical reason, and the instructions suggest naming it in the explanation.

  • People claiming a carryback

    The IRS page lists a carryback of a loss or an unused credit as a purpose for the form.

  • People whose amounts the IRS changed

    If the IRS adjusted your return and you disagree or need to report a further change, the form starts from the amounts as previously adjusted.

  • Not for a second original return

    The instructions say not to file another original return for the same year after the due date, since it could delay your refund. That is different from amending.

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Questions about Form 1040-X

When can I file Form 1040-X?

Only after your original return has been filed. The instructions say not to send a second original return for the same year.

How long does an amended return take?

The instructions say allow 8 to 12 weeks, and up to 16 weeks in some cases. Use Where's My Amended Return on IRS.gov with your TIN, date of birth and ZIP code.

Can I e-file Form 1040-X?

Yes. The IRS page says you can e-file with tax software for the current or two prior tax periods. Paper filing is also available.

Do I attach my original return?

No. The instructions say not to attach the original return. Attach an updated return, the schedules that changed and any corrected W-2 or 1099-R forms that show withholding.

What goes in the explanation?

Part II asks for the specific reason, such as receiving a corrected Form W-2 or changing your filing status. Attach a statement if you need more space.