Most states if not all have a child support division. My daughter had her support set up as a payroll deduction from my grandson's father. She never had to deal with it. I don't know if he would have to be in default or not before you can have this done. I assume your attorney would charge you for doing this. I live in Ca and I know the party who doesn't pay their child support can have any license they hold (drivers license, professional license)suspended. This is a good incentive to pay. My thoughts are with you and your children.
Other benefits to having the state withhold child suppport:
1. They will then maintain an excellent payment record and charge interest on back child support not paid. He in turn also has a concrete record of payment. This is good if you ever have to go back to court and need proof of non-payment.
2. You should be able to intercept any tax refunds he would be getting if he owes back child support. This always makes them mad!
3. If he moves out of state or changes jobs then your state has his information in the system and they will find him pretty quick and one state talks to another state and will automatically withhold child support without you having to play detective.
4. No contact with him to chase down child support and no chance of him giving you a bad check either.