20.9.10. Where the specific tax provided for in section 20.9.3 has not been collected by the vendor, the purchaser shall, at the time of the sale, report that fact to the Minister, sending him the invoice, if any, with such information as the Minister may require and, at the same time, remit to him the specific tax payable.
Every person who is required to pay tax under section 20.9.4 or 20.9.5 is under the same obligation, and this obtains at the time specified in those sections.