A parent can only be subject to a single order to pay child support with respect to for a particular child, and if there is an order between the parents to pay child support, an adult child cannot obtain a new order. The adult child can, however, apply to enforce the old order if his or her parents are not complying with the order and arrears of support are owed.

When someone does not pay child support, or pays less that he or she is required to pay, ''arrears'' build up. The arrears are the sum of the money that should have been paid according to the court order but wasn't paid. Arrears are a ''judgment debt'', just like any other debt owing because of a court order which that requires someone to pay money to someone else. Judgment debts can be enforced under the provincial ''Court Order Enforcement Act'', which allows the debtor's wages and benefits to be garnished, real property and personal property to be sold to pay off a judgment debt. Interest, calculated under the ''Court Order Interest Act'', is owing on judgment debts.