Finalisation of provisional assessment requires speaking orders if altered and acceptance plus payment obligations if confirmed. Finalisation of provisional assessment requires a speaking order and observance of principles of natural justice when final assessment contradicts the provisional finding. If the provisional assessment is confirmed, acceptance by the importer or exporter must be ascertained and they must be notified of the finalisation date. Where a deficiency remains after adjustment of amounts paid, the bill of entry or shipping bill may be returned for payment and the importer or exporter is liable for interest as provided under the Act.