Exclusion from unjust enrichment: excess customs duty refundable when overpaid and shown in self-assessed or reassessed bill of entry. Clause 91 inserts clause (g) into section 27(2) of the Customs Act to exclude from unjust enrichment duty paid in excess by an importer before an order permitting clearance for home consumption where the excess is evident from the bill of entry in a self-assessed bill of entry or where the duty actually payable is reflected in the reassessed bill of entry in a reassessment.