Casual trader obligations: pre-notification, security deposit, daily tax accounting, registration, return and nil taxable quantum. A casual trader must notify the Commissioner before commencing business, deposit a prescribed security, keep daily tax accounts, render an immediate return after concluding business and abstain from issuing tax invoices; the Commissioner registers the trader, issues forms for bringing in and taking out goods, examines returns and accounts, assesses and serves a notice within the statutory window, adjusts dues against security, refunds balances and releases security once liabilities are satisfied; the taxable quantum for a casual trader is nil.