Form 1040-X
Amended U.S. Individual Income Tax Return
Correct a Form 1040 you already filed — to fix income you left off, change your filing status, add a dependent, or claim a deduction or credit you missed.
Editing happens entirely in your browser — the form is never uploaded to a server.
What is Form 1040-X?
Form 1040-X is how you amend a return that has already been accepted. You file one 1040-X per tax year you're correcting. It has three columns: column A is the figures from your original return (or as last adjusted), column C is the corrected figures, and column B is the difference. Part III is a plain-language explanation of what changed and why.
You do not redo the whole return — you attach only the forms and schedules affected by the change (for example a corrected Schedule A, or a late-arriving 1099). If the change increases your refund, the IRS sends the additional amount; if it increases your tax, pay the difference to limit interest and penalties.
- Who needs it
- Anyone who discovers an error on a filed 1040 — omitted income, wrong filing status, a missed credit or deduction, or a dependent added or removed. You generally do not need a 1040-X to fix a simple math error; the IRS corrects those automatically.
- Deadline
- To claim an additional refund, file within three years of the date you filed the original return, or two years from the date you paid the tax, whichever is later. There's no deadline to amend if you owe more — but interest accrues until you pay.
- How to submit
- For recent tax years you can e-file the 1040-X through tax software. Otherwise mail the signed form, with the affected schedules attached, to the address in the 1040-X instructions for your state. Amended returns are processed manually and can take several months.
Form 1040-X — line-by-line
Tax year
Check or write the single calendar year you are amending. File a separate 1040-X for each year.
Filing status
Your filing status for that year — check the current one, and note if it changed from the original return (you generally can't switch from joint to separate after the deadline).
Lines 1–11 — Income and deductions
For each line, column A (original), column B (net change), column C (correct amount) for adjusted gross income, deductions, and taxable income.
Lines 12–22 — Tax, credits and payments
The corrected tax liability, credits, withholding and payments, following the same three-column layout.
Lines 18–23 — Refund or amount you owe
The overpayment already refunded to you, the additional refund you're now claiming, or the additional tax you owe.
Part II — Dependents
Complete only if you are adding or removing a dependent.
Part III — Explanation of changes
A clear sentence or two for each change: what line, what it was, what it should be, and why.
Form 1040-X — frequently asked questions
Do I need to amend for a math error?+
No. The IRS recalculates arithmetic automatically and sends a notice. Amend only for changes to income, deductions, credits, filing status or dependents.
How long does an amended return take?+
Typically 8–12 weeks, and often longer — amended returns are reviewed by a person. You can track it with the IRS 'Where's My Amended Return?' tool.
Should I wait for my original refund before amending?+
Yes. Let the original return finish processing and any refund arrive first, then file the 1040-X.
Can I amend more than one year at once?+
You file a separate 1040-X for each year, but you can mail them together in one envelope.
Related forms
The blank Form 1040-X offered here is the version published by the Internal Revenue Service (IRS). Official page and instructions .
PDFCure is not a government agency and does not provide tax, legal, or immigration advice. This page is general information — for your specific situation, follow the official instructions or consult a qualified professional. Always download the current edition from the agency before filing. Revision referenced: February 2024.