21. Notice under sub-sections (6) and (7) of section 13.—

The Commissioner shall, before proceeding to assess the 1[hotelier] to tax under sub-section (6) or (7) of section 13, call upon the hotelier by a notice in Form 12 to show cause as to why he should not be so assessed. The date for compliance with the notice shall not be earlier than fifteen days from the date of service thereof.