Refund of tax paid during investigation permitted after finalization, subject to appeal-period timing and withholding conditions. Voluntary tax payments made during investigation may be refunded if investigation or adjudication results in no or reduced liability. A dedicated accounting mechanism and a streamlined refund application-supported by a Chartered Accountant's certificate, with a threshold for self-certification-are recommended. Refund sanctioning should occur after a time limit concurrent with the appeal period, and refunds may be withheld only upon an obtained stay; exceptional withholding by senior officers must carry interest. Refunds may concern CGST, SGST or IGST.