Customs duty refunds available where duties were not leviable or paid in excess, permitting recovery of excess duty and interest. Refunds arise where import or export duties are not leviable or have been paid in excess because of missing information, non submission of documents supporting lower valuation or duty rate, or operational events such as re importation, return to exporter, relinquishment of title, shortage, short landing or pilferage. Both importers and exporters are entitled to claim refunds of excess duty, and where interest has been paid on the excess duty, a corresponding refund of such interest may also be claimed.