Test purchase authority enables compliance checks of tax invoice issuance, requiring refund and cancellation if goods are returned. Power to conduct test purchases allows the Commissioner of CGST/SGST or an authorized officer to cause an authorised person to buy goods and/or services from a taxable person's business premises to check issuance of tax invoices or bills of supply; if the goods are returned by the officer, the taxable person or person in charge must refund the amount paid and cancel any tax invoice or bill of supply issued.