No. Unless he has a court order stating as much, he can't prove the residency test for dependents. Go a head and file and include a letter with your return that shows that the child has lived with you. You can always ask the child support enforcement office to seize his returns every year until the support payments are caught up.

Legally, he can not claim your son on his taxes. In fact, he is substantially behind on child support so in most states, his rights for visitation can easily be revoked. I would suggest contacting your local district attorney office to have your ex served for money owed to you. If your ex attempts to claim your son before you do, he will be audited and subjected to fines. It is a safe bet for you to continue claiming your son.

Unless the court has stated in your agreement that he may claim your child for tax purposes, he may not. Without a court ordered agreement that states he may make the claim, the IRS would expect you, the custodial parent, to claim your child. The only other way your ex could make the claim is if you gave him permission by annually signing IRS Form 8332 for him.

Your ex cannot claim this child otherwise because the child does not live with him and he does not provide more than 50% of the child's financial support. If the state is already after your ex for back child support, there's a very good chance that any refund he is hoping to get is going to be held by the IRS to help bring his child support current.

While it's possible for him to submit a tax return before you, and even get the refund, it won't change your right to claim your son one bit.

When you go to file, if he has already claimed your son, it will reject any e-file you will attempt because your son will already be on another taxpayer's return. This is not really a big deal. Simply mail in a paper copy of your return. Once the IRS receives it, they will flag both returns, and request proof from both taxpayers that they are the proper person to claim the dependent.

You have school and medical records, at 16 he may already have a driver's license that clearly show his home address, and it will all match yours. His father has no such proof. The IRS will allow your dependent and you'll get your refund. This will slow down getting your refund, but it won't stop it. If he'd already gotten a refund, he'll have to pay it all back, plus interest and penalties. More likely though, if he's behind in child support, they would have held his refund for being in arrears. The offset office holds the funds before sending to your state for things just like this.

Thanks