Q. When my ex and I divorced, we agreed to share the child dependency exemptions even though the kids live with me and only spend every other weekend with him. I claim our older child and my ex claims our younger child. When there is only one child left we alternate the deduction every other year.

Recently our older child was considering attending the college where my ex works. My ex could have been eligible for a tuition reduction as a benefit of his employment so we agreed to swap children for 2023 taxes because my ex needed to claim our older child to be eligible for the tuition credit. As it turns out, our older son is going to UMass instead, so we will revert back next year to our assigned child deductions.

However, my ex is angry now because he received less of a child tax credit this year than he usually receives – something to do with the age of the child he claimed. He is now trying to claim I owe him $1,500 for the difference in the tax credit he thinks he is due versus what he got.

Did I do something wrong? Can he deduct the $1,500 from what he owes to UMass for our older child which he is threatening to do?

A. While I have not seen your divorce agreement, most agreements say they cannot be changed unless the change is agreed to in writing. Some require formal notarization for such written changes and filing with the court in order to formalize it. I suspect a written agreement to swap which child you are each claiming as a dependent in a particular year given the circumstances will be honored by a court even if you did not have that agreement notarized and presented to the court. It was a minor, one-off, change which could have had a significant financial benefit.

You did nothing wrong. Certainly, he could try to take you back to court claiming you are in contempt for claiming the wrong child, but he will lose because he agreed in writing to the change and then claimed your older child as a dependent per that agreement. He cannot unilaterally deduct $1,500 from what he owes for UMass – if he does, you should file a complaint for contempt against him.

Perhaps the easiest approach is pointing out the difference in what he would have had to pay if your older child attended his college versus what he is contributing to UMass. Maybe he will recognize the win and drop it.

Email questions to whickey@brickjones.com