yes and yes
No, it is still owed with interest. The back child support was supposed to be paid while the child was growing up. Check your state laws.
Sometimes State child support agencies keep more than account for a child in order to differentiate between current support and arrearages, support owed to the other parent and support owed to the State, or support owed to more than one State. However, only one support order can be in effect for any given period of time.
he will have to pay back child support if owed unless mother agrees not to or he will have to pay back support if owed to state like if mother was on state aid,but no he will not have to pay for future support
Support is owed to the parent (or the State), not the child.
That is odd. Here in this state Maine it is noted as a child support payment and does go as such on records, when given to the custodial parent for past due child support owed as such a payment to child support and should be a credit towards the child support owed. You need to check with your State Child Support as you did not mention the State you are in. But where it is federal it should be with all states, not just one. But you need to check with the Child Support Enforcement of your state as to why it was not put down as a payment for past due child support and why you were not credited for the amount as of yet. You do have the right to call and ask as the non custodial parent and it is your money that was taken away. So you do have the right to know why.
Only if the owed parent is deceased
Yes, but you must go through your state to get it.
Check link below
Depends on the state. Texas allows overpayments to be requested from the person who received them although they knew they were not owed. If not, you can sue them. Check you state laws.
Depending on the state, yes. See link
If a State has referred the case to the IRS and the check is issued to the obligor under his SSN, it will likely be intercepted and sent to the State that submitted the referral. That State will determine how much is due the custodial parent and how much is due the State.
It's possible, e.g., that one number is being used to track support owed to the other parent and a separate number to track support owed to the State(s).