40 Pa. Stat. § 676
Any domestic mutual fire insurance company, incorporated by a special act of the Legislature prior to May first, one thousand eight hundred and seventy-six, and having a surplus and unearned premium reserve as required in section one, and whose charter provides for a premium deposit which shall remain as a pledge for the performance of the depositor's covenants, which deposit, under the provision of such charter, shall be returned to the depositor at the expiration of the policy, together with a proportional dividend of the profits after deducting losses and incidental charges, and whose charter further provides that the net profit, arising by interest or otherwise, shall be ascertained yearly to every member in proportion to his, her, or their deposit for which each member shall have credit on the company's books, payable at the cancellation of the policy, may, instead of collecting such deposit money as above provided under such charter, charge a cash premium in advance, on which no dividend or return shall be due or accrue, other than return premiums on canceled policies.
40 P.S. § 676