Summary assessment powers enable expedited tax assessment to protect revenue where delay would prejudice collection. A proper officer may, with prior permission of the Special Commissioner/Additional Commissioner, make a summary assessment on evidence of tax liability if delay would prejudice revenue; if the taxable person is unascertainable and the liability concerns supply of goods, the person in charge of the goods is deemed the taxable person. The taxable person may apply within thirty days to have the order reviewed, and the Special Commissioner/Additional Commissioner may withdraw the summary order and proceed under the ordinary reassessment procedures if the order is found erroneous.