When you should amend
- You reported income incorrectly or forgot an income source.
- You claimed (or missed) deductions or credits.
- You used the wrong filing status.
- You need to change the number of dependents.
- You received a corrected W-2 or 1099 after filing.
When you usually don’t need to amend
Do not amend for simple math errors; the IRS typically corrects those and sends a notice. If you forgot to attach a form or schedule (like a W-2), the IRS will usually write to ask for it. Wait for the notice.
Deadlines
To claim a refund, you generally must amend within three years of the date you filed the original return or two years from when you paid the tax, whichever is later. Amending to report more tax has no formal deadline, but it is better to do it promptly to limit interest and penalties.
How to amend step by step
- Wait for your original return to be processed if it is still in progress, and for any refund to arrive. You can still file an amended return later.
- Gather your original return and new documents.
- Complete Form 1040-X. It uses three columns: original amounts, net change, and correct amounts. Explain the change in Part II. Attach any new or changed forms and schedules.
- E-file or mail. The IRS allows e-filing of Form 1040-X for recent tax years through software. Otherwise mail to the address in the instructions.
- File a separate 1040-X for each tax year.
- File your state amended return if the change affects your state taxes. State rules differ.
How long it takes
Amended returns are processed manually and can take far longer than original returns — the IRS has said it can take 16 weeks or more. Check status with the IRS “Where’s My Amended Return?” tool, available a few weeks after filing. Our page on refund status covers original returns.
If you owe more
Pay as soon as you file to limit interest. If you cannot pay in full, see your options.
If you receive a refund
Refunds from amended returns are issued by check or direct deposit separately from the original. Don’t be surprised if it arrives months after you filed.
Special cases
- Net operating losses and some credits have different amendment timing.
- Identity theft: contact the IRS using its identity theft resources rather than amending.
- Math errors on notices: follow the instructions on the notice.
Frequently asked questions
How long does an amended return take?
The IRS has said it can take up to 16 weeks or longer. You can track it with the IRS amended return status tool.
Can I e-file an amended return?
Yes, for recent tax years through software that supports Form 1040-X. Older years may need to be filed on paper.
Do I need to amend for a math error?
Usually not. The IRS corrects math errors and sends a notice.
Official sources
General information only — not tax, legal or financial advice. Tax figures change every year; verify the current numbers at IRS.gov or with a qualified professional. Read the full disclaimer.