If the return is being rejected by the IRS because “someone else has claimed” your dependent, the most likely reason is that the other parent claimed the exemption (and may have erroneously claimed the earned income credit, child and dependent care credit, filing head of household if he is the noncustodial parent).
If possible, you can verify by checking box 6c, line 66a, and 49 of his 1040. If the dependent's information is box 6, he claimed them as a dependent. If there are entries in lines 49 or 66a, he may have claimed the custodial parent’s child tax benefits.
If this is the case and your partner claimed the child, you have a few options. They are as follows:
You can e-file single and not claim any information about your daughter. This keeps any issues for the other person.
Ask your partner to amend their return. Extend and file in mid summer (amended returns can take up to 16 weeks to process).
You can mail your return and claim head of household, earned income credit, and the child and dependent care care credit. If you have documentation, you will get the best return.
If you use option 2, the IRS will write to you and the other person and require you both provide documentation to prove the child's residency with you. You will need to send a collection of the following:
Rent receipts
Utility bills
School records for your child (if applicable)
Doctors notes, or a pastors note.
Notes from neighbors, or third party people that the child lives with you
Anything you can come up with the proves the child was with you.
If your partner did not claim the child, use option 3. This will take some time, but this is the only way to correct the issue.
