I put the wrong last name on my dependant

[LeonardS]

The IRS tracks dependants by their social security number so the fact that you put the incorrect last name should not be an issue.  However, if your return is rejected due to the incorrect correct the name you will correct the name and refile your return.

[jngstone]

how do i fix it

[FangxiaL]

E-file won't go through if the name and SSN do not match IRS records. You can go back to My Info and click on Edit next to your child's name and make the necessary changes.