If any part of any underpayment of tax required to be shown on a return is due to fraud, there will be added to the tax an amount equal to 50% of the underpayment. If a 50% addition to the tax for fraud is assessed with respect to an underpayment then the addition as provided in § 119.21 (relating to failure to pay tax due to negligence or intentional disregard of rules and regulations) will not be assessed with respect to the same underpayment.
61 Pa. Code § 119.22