72 Pa. Stat. § 8102
Parts III, IV, VI, and VII of Article IV are incorporated by reference into this article in so far as they are consistent with this article and applicable to the tax imposed hereunder. However, notwithstanding the provisions of subsection (d) ofsection 403 of this act, if the officers of any corporation subject to tax under this article shall neglect or refuse to make any report as herein required or shall knowingly make any false report, there shall be added by the department to the tax determined to be due a penalty of five per cent of the amount of tax due for each month or fraction thereof until the penalty has reached twenty-five per cent, and thereafter at the rate of one per cent per month. No such amounts added to the tax shall bear any interest whatsoever.
72 P.S. § 8102