Violation of divorce agreement

My divorce agreement says I have the right to claim the children on tax returns, but my wife filed first and claimed them. My returns were rejected and I now have to refile without them and pay an extra $2500. What can I do to get this money back?

Can I withhold child support?

I would not advise you to withhold child support. In the eyes of the court, two wrongs don’t make a right. You should contact the IRS and provide them with a copy of your agreement. Even if they have already processed her taxes, you should be able to use the deduction and have them go after her. If that doesn’t work, you will need to file a breach of contract action against her for failure to follow the agreement.