Interest on delayed refunds secures payment entitlement when statutory refund periods lapse, with higher rates for appellate derived claims. Liability to pay interest on delayed tax refunds arises where a refund ordered under the GST refund provisions is not paid within sixty days of receipt of the refund application; interest runs from the day after that period until payment at rates prescribed by government notification, with a higher prescribed rate where the refund claim follows a final adjudicatory or appellate order. An appellate or judicial refund order reversing a proper officer is deemed to be an order under the primary refund provision, thereby triggering the same interest entitlement and timing rules.