75 Pa. C.S. § 9612
If the department ascertains that a person designs quickly to depart from this Commonwealth, or to remove therefrom his property or any property used by him in operations subject to this chapter, or to discontinue business, or to do any other act tending to prejudice or render wholly or partly ineffectual proceedings to assess or collect such tax, whereby it becomes important that such proceedings be brought without delay, the department may immediately make an arbitrary assessment of the amount of tax due, whether or not any report is then due by law, and may proceed under such arbitrary assessment to collect the tax, or compel security for the tax, and thereafter shall cause notice of such finding to be given to the motor carrier, together with a demand for an immediate report and immediate payment of the tax.
75 Pa.C.S. § 9612