If you discover a mistake on your federal return and it was already accepted by the IRS, you will have to amend it by filing a 1040X. These mistakes may include not reporting some income from a form that came later than expected, claiming deductions or credits you shouldn't have claimed, failing to claim some deductions or credits to which you are entitled, or needing to change your filing status.  

Contact your local Liberty Tax Service office for help with filing a 1040X.