When to amend. You should amend your tax return if you need to correct filing status, the number of dependents or total income. You should also amend your return to claim tax deductions or tax credits that you did not claim when you filed your original return.
When NOT to amend. In some cases, you don’t need to amend your tax return. The IRS will make corrections, such as math errors, for you. If you didn’t include a required form or schedule, for example, the IRS will mail you a notice about the missing item.
Form 1040X. Form 1040X is used to amend a federal income tax return that you filed before. It must be filed by paper; it cannot be filed electronically.
More than one tax year. If you need to file an amended return for more than one year, use a separate 1040X for each tax year. Mail them in separate envelopes to the IRS.
Amending to claim an additional refund. If you are waiting for a refund from your original tax return, don’t file your amended return until after you receive the refund. You may cash the refund check from your original return. Amended returns take up to 16 weeks to process.
When to file. To claim a refund file Form 1040X no more than three years from the date you filed your original tax return. You can also file it no more than two years from the date you paid the tax, if that date is later than the three-year rule.
Track your return. You can track the status of your amended tax return three weeks after you file with “Where’s My Amended Return?”