Demand notice under Insolvency Code: prescribed Form 3 invoice serves as formal demand that may trigger insolvency proceedings. Form 3 prescribes the standard format for a demand notice/invoice under the Insolvency and Bankruptcy Code, 2016 and its Rules (clause (a) of sub rule (1) of rule 5). It functions as the formal statutory invoice by which a creditor makes a demand for payment; failure by the debtor to comply with that demand permits the creditor to proceed with insolvency-related remedies under the Code.