53 Pa. Stat. § 1296
Any such person, co-partnership, association, or corporation, who has no contractual relationship, express or implied, with the contractor furnishing the said additional bond, shall not have a right of action upon said additional bond, unless the said person, co-partnership, association, or corporation shall have given written notice to said contractor, or to his, their, or its surety, not later than ninety (90) days from the date on which the said person, co-partnership, association, or corporation furnished, supplied, or performed the last of the material or labor for which the said claim is made, stating, with substantial accuracy, the amount claimed and the name of the party with whom the said person, co-partnership, association, or corporation contracted. Said notice shall be served either in the manner now or hereafter provided by law for the service of a summons, save that service need not be made by the sheriff, or by mailing said notice by registered mail, postage prepaid, in an envelope addressed to the contractor at the contractor's last known place of business of residence, or to the surety at any of its offices or places of business.
53 P.S. § 1296