Invoice requirement: Mandatory serialised invoices and authentication govern removal of excisable goods, including proforma, transhipment and pass-out procedures. Removal of excisable goods is permitted only under a duly issued, serially numbered and authenticated invoice containing specified particulars. Invoices must be in triplicate, serial numbers start each financial year, hand-written numbering is not allowed, and computer-generated unique numbers are acceptable. Special proforma invoice rules apply to certain textiles and garments with later finalisation; multiple invoice books require authority and distinct serial sequences. Manufacturer procedures cover split consignments, parent invoices for disassembled machinery, transhipment endorsements, cancellation intimation, and detailed Daily Stock Account entries. Pass-Out and pipeline accountal regimes prescribe provisional entries, reconciling deliveries and losses, pre-authenticated serial documents, and final duty determination.