72 Pa. Stat. § 4141
From and after the passage of this act, whenever a revision of any settlement or resettlement is made by the Department of Revenue, or any other agency of the State Government charged with the settlement or resettlement of State taxes, bonus, penalties or interest, when it may appear from the accounts or from other information that any person, firm, corporation, association, limited partnership, or joint-stock association, municipality, school district, or body politic, has had an erroneous or illegal settlement made against the same, and a settlement or resettlement has been made according to law, and a credit granted therefor, that such credit may be assigned, in whole or in part, to any other person, firm, corporation, association, limited partnership, joint-stock association, municipality, school district, or body politic, on account of any taxes, bonus, penalties, or interest due or to become due from such person, firm, corporation, association, limited partnership, joint-stock association, municipality, school district, or body politic, with like force and effect as if the same were paid in money, and such assignment or transfer, upon approval of the Department of Revenue, shall be final and conclusive as to the Commonwealth and the party or parties to such assignment or transfer: Provided, however, That such credit shall not be payable in money to any grantee or assignee out of any funds of the Commonwealth.
72 P.S. § 4141