To correct an error on the original filed income tax return you will have to use the 1040X Amended Individual Income tax return available by going to the IRS gov web site and using the search box for 1040X
File a separate Form 1040X for each year you are amending. Mail each form in a separate envelope. Be sure to indicate the year of the return you are amending on the front of Form 1040X.
The 1040X form now has just one column where the Correct Amount is the only figure entered, making it easier to make changes to previously filed returns. There is an area on the front of the form to explain why you are filing Form 1040X. Generally, to claim a refund, Form 1040X must be filed within 3 years from the date of your original return or within 2 years from the date you paid the tax, whichever is later. Returns filed before the due date (without regard to extensions) are considered filed on the due date.
Attach copies of any forms or schedules that are being changed as a result of the amendment including any Forms W-2 received after the original return was filed.
The correctly filled out 1040X amended individual income tax return will have to be mailed to the correct IRS address and you can find the address in the instructions for the 1040 tax form.
Normal processing time for Forms 1040X is 8 to 12 weeks from the IRS receipt date.
Please Note: Your state tax liability may be affected by a change made on your federal return. For information on how to correct your state tax return, contact your state tax agency.