Recordkeeping obligations require taxable persons to maintain accounts, face audit if turnover threshold met, and possible tax determination for unaccounted supplies. Registered taxable persons must maintain true and correct accounts at the principal place of business (and at each specified place where applicable), including records of production, supplies, stock, input tax credit and output tax; accounts may be kept electronically as prescribed. The Commissioner may notify classes for additional or alternative account-keeping. Taxpayers exceeding the prescribed turnover limit must obtain statutory audit and submit audited accounts and reconciliation statements. Failure to account for goods or services permits the proper officer to determine tax on unaccounted supplies under sections 66 or 67. Warehouse operators must maintain consignor, consignee and related records.