Accounts and records in GST: Registered persons must maintain prescribed books and face tax determination for unaccounted items. Registered persons must maintain prescribed accounts at their principal place of business (and place-wise for additional locations), keeping records of production, inward and outward supplies, stock, input tax credit, output tax, invoices and vouchers, advance accounts, supplier/recipient particulars and storage locations; non-compliance permits tax determination on unaccounted goods or services and application of assessment provisions, while the Commissioner may require or relax additional record-keeping obligations.