It depends on the type of mistake you made:
▪ Many mathematical errors are caught during the tax return processing and corrected by the IRS, so you may not need to convert these mistakes.
▪ Suppose you didn’t claim the correct filing status, or you need to change your income, deductions, or credits. In that case, you should file an amended or corrected return using Form 1040X, Amended U.S. Individual Income Tax Return.
When filing an amended, corrected return:
▪ Include copies of any forms and/or schedules you’re changing or didn’t include with your original return. To avoid delays, file Form 1040X only after you’ve filed your original return. Generally, for a credit or refund, you must file Form 1040X within three years after the date you timely filed your original return, or within two years after the date, you paid the tax, whichever is later.
▪ Allow the IRS up to 16 weeks to process the amended return.