What is the name of your state (only U.S. law)? New Hampshire. I have a few questions regarding overpayment of child support. 1. What court to I petition to recoup overpayment of child support? 2. If I live in NH and the child support case was held in NJ via telephone conference in which Overpayment was made due to custodial parent receiving retroactive social security payments for said child, what state do I have to file petition? 3. My child support order was vacated due to child collecting social security benefits off my benefits; family court credited the retroactive lump sum toward my child support resulting in an overpayment. Do I have a legitimate case to petition a court to recoup overpayment? I appreciate any guidance in this matter... alan