My son owes back child support balanace of around 23000. can the amount be reduced if paided in full

It depends. If the child support arrears already have been adjudicated by a court, then the number cannot be reduced. If they have not been adjudicated then you can negotiate with the Mother of the children and see if she would agree to reduce the amount. If he has not already, your son needs to move to modify the child support payments to come up with an affordable monthly payment. Best of Luck, Helena Y. Farber, Esq. www.farberlawpa.com