Demand of duty: authorities may issue notices and adjudicate short payment or erroneous refunds within statutory limitation. Departmental recovery of unpaid, short-paid, unlevied or erroneously refunded duty proceeds by a demand notice giving reasons and an opportunity to show cause, with written and oral submissions, including a personal hearing, considered by the adjudicating authority; appeal lies to the higher forum. The notice must normally be issued within one year of the relevant date (typically the return filing or due date, adjustment date for provisional assessments, or refund/payment date), but the limitation extends up to five years where the default is due to fraud, collusion, wilful mis-statement, suppression of facts or deliberate contravention intended to evade duty.