Oops made a mistake... How to Amend your Individual Tax Return
INTERNAL REVENUE SERVICE
If you discover an error after filing your return, you may need to amend your return. The IRS may correct mathematical or clerical errors on a return and may accept returns without certain required forms or schedules. In these instances, there's no need to amend your return. However, do file an amended return if there's a change in your filing status, income, deductions, or credits. Use Form 1040X.pdf, Amended U.S. Individual Income Tax Return, to correct a previously filed Form 1040.pdf, Form 1040A.pdf, Form 1040EZ.pdf, Form 1040NR.pdf, Form 1040NR-EZ.pdf, or to change amounts previously adjusted by the IRS. You can also use Form 1040X to make a claim for a carryback due to a loss or unused credit; however, you may also be able to use Form 1045.pdf, Application for Tentative Refund, instead of Form 1040X. Also, if the Form 8938.pdf, Statement of Specified Foreign Financial Assets, applies to you, file it with an annual return or an amended return. See the Form 8938 Instructions for more information.
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https://www.irs.gov/taxtopics/tc308
CALIFORNIA FRANCHISE TAX BOARD
For taxable years beginning on or after January 1, 2017, the Schedule X has replaced Form 540X, Amended Individual Income Tax Return. For additional information, see Instructions for Filing Amended Returns in the personal income tax booklets.
Use Schedule X to determine any additional amount you owe or refund due to you, and to provide reason(s) for amending. Attach Schedule X to your amended tax return.
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