Ensure your case has been filed with your state's child support collection bureau. Every state monitors the payment of child support through a collection agency. The non-custodial parent pays the agency, which in turn distributes the money to the custodial parent. In this way, the state keeps track of how much money has been paid and whether or not the non-custodial parent has fallen behind on payments. It's important to remember that any money transferred directly from the non-custodial parent to the custodial parent is not counted as a support payment.
File a Motion to Enforce the child support order with the civil court that issued the divorce decree and approved the child support agreement. Alternatively, your state may require you to file a Motion for Contempt or Complaint for Contempt of Court. The court will schedule a hearing, which you must attend; the court may allow a telephonic appearance if you have moved out of the county or state. Explain to the court how and when the child support payments fell behind and the effect this is having on your ability to care for your children. After hearing your arguments, and those of the non-custodial parent, the court will either grant or deny your motion.
File the granted motion with the state's child support enforcement agency, if necessary. Enforcement actions may be carried out directly by the court or by the child support enforcement agency and may include garnishment of wages, interception of tax refunds, levies of bank accounts and punitive measures, such as driver's license suspension. If the non-custodial parent does not bring payments up to date, some states prescribe probation or jail time.
Hire a private collection agency if the court order fails to resolve past-due child support. Do careful research on the agency before you take this step and check for any consumer complaints against the agency with the state bureau responsible for regulating businesses. With your written authorization, these agencies can contact the non-custodial parent to work out a settlement of the matter, or in some states, levy wages or bank accounts.