"according to divorce decree"
Divorce decrees and custody agreements hold no weight with the IRS. The IRS has their own rules on this that no judge below a federal judge can override. Since federal judges don't handle divorce or custody issues, that's not gonna happen.
Basically, the IRS defines the custodial parent, and the non-custodial parent.
- Custodial parent: The parent with whom the child lived for more than 182 nights of the tax year, and provided more than half of the child's support.
- Non-custodial parent: Does not meet the requirements to qualify as custodial parent.
The custodial parent qualifies to claim the child and in most cases will also qualify to file HOH. In a case such as yours the non-custodial parent can claim the child, provided the custodial parent (as defined by the IRS, and not as defined in any divorce or custody agreement) provides a signed IRS Form 8332 to the non-custodial parent releasing their legal right to claim the child, to the non-custodial parent.
Where the legal custody agreement can come into play, is that the lower court judge can order you to sign the 8332 and hold you in contempt of court if you refuse. But even so, the IRS doesn't care about that and will not get involved in any legal proceedings concerning this. Without a signed 8332 the non-custodial parent flat out can not claim the child. Period.
The fact you pay child support does not play into your tax situation in any way. Child support you pay is not tax deductible. Child support received by the other parent is not reportable or taxable income to them.
In order to qualify to claim HOH, one of the requirements is that you must also be claiming a qualified dependent. So if you will be providing the other parent a signed 8332 releasing your right to claim the child, the only filing status available to you is single, and that's it. (Assuming you have no other qualified dependents.)
