It depends on the type of mistake that was made. Many mathematical errors are caught in the processing of the tax return itself. If you did not attach a required schedule, the service will contact you and ask for the missing information.

If you did not report all your income or did not claim a credit, you are entitled to file an amended or corrected return using Form 1040X, Amended U.S. Individual Income Tax Return. Include copies of any schedules that have been changed or any Forms W-2 you did not include. The Form 1040X Amended U.S. Individual Income Tax Return should be submitted after you receive your refund or by the due date of the return, whichever is earlier. Generally, to claim a refund, the Form 1040X Amended U.S. Individual Income Tax Return must be received within three years after the date you filed your original return or within two years after the date you paid the tax, whichever is later.

If the IRS has already accepted your return, and you need to make corrections, you will need to amend your return. You will need Form 1040X to make any adjustments to your original return.

You will need to file a 1040X Amended U.S. Individual Income Tax Return which is the form for amended returns. The amended return will ask for your original amount, the net change, and the corrected amounts.

Generally, to claim a refund, Form 1040X Amended U.S. Individual Income Tax Return must be received within 3 years from the date you filed your original return or within 2 years from the date you paid the tax, whichever is later.

Yes, you can amend your return as many times as necessary to be sure you are reporting the correct information. What you would need to do is file another Form 1040X. This time you would use your amended values as the original values. You would look at the first Form 1040X that you filed, and you would enter the values in Column C in Column A on your new Form 1040X Amended U.S. Individual Income Tax Return. Then enter your new/correct values in Column C and figure the difference between them for Column B.

You mail in the amended return to the IRS address assigned for your situation and where you live. ftax Taxes at ftax.com will provide you the address after you complete your amended return using ftax Taxes at ftax.com.