Duty free input accounting requires detailed entries and documentary evidence, with CA certification ensuring register accuracy. Register sets out required entries for accounting duty free inputs under Advance Authorisation/DFIA including authorisation numbers, input descriptions and quantities (including wastage), exported products and quantities, inputs consumed, treatment of excess inputs through additional exports, proportional reduction or payment of customs duty with interest, and requires documentary evidence for adjustments. Authorisations may be clubbed for accounting but transferable DFIAs must be reported individually; post export replenishment must state duty status of inputs and details of redeemed authorisations for the licensing year must be furnished.