Court papers say I claim ny daughter till she is 18 I have full custody he just claimed her is it legal

[DavidD66]

If you are entitled to claim your daughter and someone else already filed and claimed her, you can still claim her on your tax return; but you won't be able to e-file your return.  You will have to print and mail your return.  The IRS will then contact both you and the other person that claimed your daughter to determine who is legally entitled to claim her.   If "he" is your ex-spouse, then you can ask him to file an amended return not claiming your daughter.  Once the amended return is processed you would be able to e-file, but it could take longer for the amended return to be processed than it would to sort things out if you filed by mail.