Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 12560. Contracts without appropriation unenforceable;  payment for supplies or services

No liability shall be enforceable against the city, by any action at law in equity or otherwise, upon any contract not supported by a previous appropriation of council, or to enforce payment for any materials or supplies furnished to the city or to any department, officer, board, commission, trust, committee, or other agency, whose financial requirements are to be met out of the proceeds of taxes levied by the council or out of any other funds over which the council has control, unless the council shall have made a previous appropriation therefor;  and no payment may be enforced by any such action for services rendered to the city or to any such department, officer, boards, commission, trust, committee, or other agency, unless there shall have been a previous appropriation by the council to pay for such services:  Provided, however, That the council may by ordinance authorize payment for material furnished or services rendered without a previous appropriation, if the same is agreed to by a two-thirds vote of all the members elected thereto, and is approved by the mayor.  Ordinances making appropriations for such payments shall relate to no other subject, and shall set forth in separate items the names of each beneficiary to whom such appropriation is made and the amount he is to receive.