Form 80-170, Mississippi Amended Individual Income Tax Return, is filed by individual resident taxpayers to amend an individual income tax return (Form 80-105) already filed. A separate return must be filed for each tax year being amended. The amended return should be mailed to the address provided on the form.
If you were a nonresident or part-year resident, in the year being amended, do not complete this form as you will need to complete Form 80-270, Mississippi Nonresident or Part Year Resident Amended Individual Income Tax Return. If the change is from nonresident to resident status, then indicate as such in the explanation of changes on page 2 of Form 80-170.
File an amended return, Form 80-170, any time you need to correct your Mississippi return. In general, if you amend your federal return, you will need to amend your state return.
You may apply for a refund on an amended return within three years of the original due date of the return (including extensions). If no return was originally filed, a refund may be requested by filing a return within three years of the original due date for filing the return.