If you discover you’ve made an error on your return after you’ve already filed it, you may need to amend your return. In some cases though, you may not have to. For instance, if the errors are clerical or mathematical, the IRS will usually correct them during the processing of your original return. Or, if you failed or forgot to include a required form or schedule, the IRS will typically send you a letter asking for the missing document.
However, you do need to amend your tax return if you have to correct your filing status, the number of dependents you claimed, or your 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. To amend a federal income tax return that you previously filed, you must use IRS Form 1040X. If you need to file an amended return for more than one year, use must use a separate Form 1040X for each affected tax year, mailing them in separate envelopes to the IRS. Make sure you check the box for the year of the return you are amending on the Form 1040X. An amended tax return cannot be filed electronically. If you owe additional tax for a tax year for which the due date for filing has not passed, file Form 1040X and pay the tax by the due date for that year to avoid penalties and interest.
Form 1040X has three columns: ‘Column A’ shows amounts from the original return; ‘Column B’ shows the net increase or decrease for the amounts you are changing; and ‘Column C’ shows the corrected amounts. You should explain what you are changing and the reasons why on the back of the form. If the changes on the original Form 1040, Form 1040A, Form 1040EZ, Form 1040NR or Form 1040NR-EZ involve also changing other tax forms or schedules, make sure you attach the the corrected forms and schedules to Form 1040X when you file the amended return.
If you are waiting for a refund from your original tax return, don’t file your amended return yet. Wait until after you receive the refund. You may cash the refund check from your original return. Amended returns take up to 12 weeks to process. If you want to claim a refund under your amended return, you generally must file Form 1040X within three years from the date you filed your original tax return, or within two years from the date you paid the tax, if that date is later than the three-year rule.
The Where’s My Amended Return? online tool at the IRS website provides the status of the Form 1040X for the current year and up to three prior years. It usually takes up to three weeks from the date the amended returns were mailed before it shows up in the online tracking system. The usual time for completion of the processing of amended returns is between 8 to 16 weeks.