Ind. Code § 7.1-4-2-7

Sec. 7. Copy of Invoice. A brewer or beer wholesaler in this state, when he delivers beer to a person, shall make a true duplicate invoice showing the date of delivery, the amount and value of the shipment and the name of the purchaser. The brewer or wholesaler shall give one (1) copy of the invoice to the purchaser, and he also shall retain one (1) copy for the use and inspection of the commission and the department, for a period of two (2) years. A beer wholesaler shall keep, and retain for a period of two (2) years, a copy of all invoices for beer purchased or received by him.