Bad debt adjustment under VAT: recovered or written-off amounts affect taxable sales allocation and subsequent tax adjustments. An adjustment to tax is permitted where a dealer has written off a sale price as bad debt and claimed it as a deduction under section 36 of the Income Tax Act; the adjustment equals the tax on the written-off price provided it is recorded in the dealer's books. When the written-off price relates to sales taxed at different rates, allocation follows a specified hierarchy: interest, exempt sales, then taxable sales in ascending tax-rate order. Subsequent recoveries are treated as deemed sales and allocated in reverse order for tax adjustment.