Why is my dependent coming up as a duplicate

[rjs]

What do you mean by "coming up as a duplicate"? Do you mean that the same dependent appears twice on your tax return, or do you mean that your e-file was rejected because your dependent was already claimed by someone else? If your e-file was rejected, what is the exact complete reject message that you got, including the code?

Is your dependent a child or an adult? How old is the dependent? How is the dependent related to you?

[Mike9241]

if you received a rejection e-mail, that means someone already filed a return using the same SSN as your dependent.  once this happens, you are blocked from e-filing as long as you claim the dependent. you did not provide enough info for us to advise you as to whether you are entitled to claim them but see below for qualifying child or relative (dependent)

you are entitled to claim him/her if he/she is your qualifying child or relative 
he/she is qualifying child if all these tests are met
• he/she has the same principal abode as you for more than ½ the tax year. Temporary absences like for school are ignored
• If not a full-time student, under 19 at the end of the tax year. If a full-time student under 24 at end of the tax year.
• he/she hasn't provided over ½ his/her own support
• he/she didn't file a joint return unless there was no tax liability but merely filing jointly to facilitate refund of taxes withheld or estimates paid
or as he/she could be a qualifying relative if all these tests are met
• his/her gross income for 2020 less than $4,300
• you provided over ½ his/her support
• he/she isn't a qualifying child of another taxpayer

[rjs]

Another possible reason for an e-file rejection is that the dependent filed his or her own tax return and did not indicate that he or she could be claimed as a dependent by someone else.

We can't give you more specific help unless you provide more details.

[cyd2]

My 11 year old daughter is showing up ONLY on my state tax return twice.  Everything is correct on my federal tax return.  On my state tax return, she shows up twice, once with her correct SSN, once with a bogus SSN.

No one else claims her on their return.  How do I remove this duplication of bogus data?