Filing Form 1040X [Amended Individual Return] allows you to correct information on a tax return that has already been filed. Reasons to file an amended return may include Incorrect filing status Incorrect total income Incorrect credits or deductions Any of these changes to your return may result in a refund or additional tax due. You can prepare a 1040X with PriorTax, but only if we prepared your original return. Also, Form 1040X cannot be e-filed, so you’ll have to print it out, sign it, and mail it in to the IRS along with a copy of your original return. Be aware that you don’t have forever to claim a refund with a 1040X. You must file within three years of the original due date or two years of the date you paid the tax, whichever is later, in order to claim a refund.