The do's and don'ts of amending your tax return
What happens when you discover you made a mistake on your 2016 return that you just filed? Before you decide if you should file an amended tax return, there are a few do's and don'ts you should know. First, don't panic, and second, don't ignore the error.
Do file an amended return if you need to change your tax filing status or dependency exemptions, or you overlooked available deductions or credits.
Don't file an amended return to correct simple mathematical miscalculations or forms you forgot to attach. The IRS corrects those types of mistakes and sends you a notice.
Do file the amended return as soon as you discover your error. If you owe additional tax, filing quickly will minimize interest and penalties. However, if the change will result in a larger refund, wait until you receive the refund shown on your original return.
Don't wait too long. Amended returns must generally be filed within three years from the date you filed your original return. After that, you may no longer be able to claim any additional refund.