Accountkeeping obligations require registered persons to maintain prescribed records and expose noncompliance to tax determination. Section 35 requires registered persons to maintain true accounts at their principal place of business recording production, inward and outward supplies, stock, input tax credit, output tax and other prescribed particulars; electronic record-keeping is permissible. Owners of storage facilities and transporters must keep consignor and consignee records. The Commissioner may prescribe additional accounts or permit alternative record-keeping for specified classes. Persons above the prescribed turnover must obtain statutory audit and submit audited accounts and reconciliation statements. Failure to account for goods or services allows the proper officer to determine tax on unaccounted supplies and apply assessment and recovery provisions mutatis mutandis.