I listed my daughter in my household but selected someone else was claiming her and now my ex husband is stating his taxes were rejected due to someone else claiming her.

[jskinner1]

I did the same thing in 2020 and there was no issue for him to claim her.

[rjs]

There are a lot of things that could possibly be going on here, but no matter what, your ex-husband is not going to be able to e-file his tax return this year. He will have to print it, sign it, and file it by mail.

Here a few possibilities, but these are just guesses. And in most of these cases, there's nothing you can do about it. Your ex will just have to file his tax return by mail, claiming your daughter, and let the IRS sort it out.

Look at the Form 1040 that you filed. Is your daughter listed in the Dependents section near the top? If so, somehow you claimed her, even though you didn't intend to. If that's what happened, you should file an amended return to remove your daughter. Otherwise you and your ex-husband will both get letters from the IRS and will have to respond to the letters. But even if you file an amended return, your ex still will not be able to e-file.

If you didn't inadvertently claim your daughter, it sounds like someone other than you and your ex claimed your daughter. Is there any other family member who might have claimed her? Perhaps your parents or your ex-husband's parents? Did anyone else live in the same home with your daughter, or contribute to her support, who might have felt entitled to claim her?

How old is your daughter? Could she have filed a tax return for herself and not indicated that she could be claimed as a dependent?

Could your ex-husband be mistaken? Is he claiming any other dependents besides your daughter. The IRS reject messages are not always clear about which dependent was already claimed. Are there other children in the picture? Could your ex have mistakenly claimed the wrong child?

[Critter-3]

The ex may be trying to claim the child for things they are not allowed to claim like the HOH filing status or the EIC ...  If you properly claimed the child for only those items the custodial parent can claim then you did nothing wrong and the program is correct.  The ex needs to look at what they did ... here are the rules : 

There is no such thing in the Federal tax law as 50/50, split, or joint custody.  The IRS only recognizes physical custody (which parent the child lived with the greater part, but over half, of the tax year.  That parent is the custodial parent; the other parent is the noncustodial parent.)

Who can claim the exemption and credits depends on who is the custodial parent. (By the IRS definition of custodial parent for tax purposes - this is not the same as the legal custody that a court might grant.).

The test that the IRS uses to determine the custodial parent is where the child lived for more than 1/2 (or greater part) of the year. The IRS will go so far as to require counting the nights spend in each household - that person is the custodial parent for tax purposes (if exactly equal and more than 183 days - The custodial parent is the parent with the highest AGI, if less than 183 days then neither parent has custody so the child cannot be claimed by either parent). And yes they are that picky.

See Custodial parent and noncustodial parent  under the residency test in Pub 17

https://www.irs.gov/publications/p17#en_US_2017_publink1000170899
 
Only the Custodial parent can claim: (Child would be listed as non-dependent EIC & CC only)
-Head of Household 
-Earned Income Credit
-Child Care Credit

The non custodial parent can only claim: (Child would be listed as dependent)
-The Exemption
-The Child Tax Credit

But only if specifically specified in a pre-2009 divorce decree, separation agreement or the custodial spouse releases the exemption with a signed 8332 form - after 2009 the IRS only accepts a signed 8332 form that must be attached to the non-custodial parents tax return.