Solved
My x cannot claim the kids (per our agreement). he is asking for the kids' ssn. does he need that information?
Not for tax purposes. In some cases, the non-custodial parent claims the dependents, while the custodial parent claims Head of Household and the child credits, but from what you describe, that is not the case here.
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.