How to amend a tax return if you've already filed
Taxes 101 By National Tax Block · Nov 3, 2026
You amend a return with Form 1040-X. You generally have three years from the original filing date to claim an additional refund.
When to amend
- You received a corrected W-2 or 1099 after filing
- You missed a credit or deduction
- Your filing status or dependents were wrong
Our free Prior-Return Review checks whether an amendment would put money back in your pocket.
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