572.This Part deals with arrears and repayments and provides that arrears cannot be enforced without the leave of the court. In certain circumstances the court may order repayment of a sum which ought not to have been paid. For example, if a periodical payments order has ceased to have effect because the recipient has married or formed a new civil partnership the court may order the repayment of any money overpaid by mistake.
Commentary on Sections Schedule 5 – Financial relief in the High Court or a county court etc. Part 12 - Arrears and repayments