A return used to correct a return that has already been filed. A return should be corrected if, after it has been filed, it is determined that (1) some of your income was not reported, (2) deductions or credits were claimed that you should not have claimed, (3) deductions or credits were not claimed that you could have claimed, or (4) you should have claimed a different filing status.
A tax return filed on Form 1040X after the original return has been filed. An amended return is used to correct errors or to claim more advantageous ways of filing the original return. An amended return can also be used to carry back certain unused cr edits or a net operating loss.
A tax return filed with a 1040X within three years of an original return, which allows for correction of errors or changes regarding the original return.
A revised tax return is used to correct an error on a return filed during the previous three years and is filed on Form 1040X. An amended return can result in owing added tax or receiving a refund. This depends on the mistake you are correcting.