Less charge demand requires importers and exporters to pay shortfall when customs valuation or classification understates duty. Importers and exporters must file correct declarations of value, description, classification and exemption claims; duty is determined by the statutory assessment mechanism. If duty paid or levied is less than due, the short levied/short paid/non levied amount must be recovered. Customs officers may issue a demand cum show cause notice to recover the deficient duty from the importer or exporter, based on deficiencies in valuation, classification, description or exemption claims.