72 Pa. Stat. § 715
Every insurer, organized, admitted, or licensed to transact the business of marine insurance within this Commonwealth, shall file, on or before the first day of June in each year, with the Department of Revenue, and in the form prescribed by it, a report of all the items pertaining to its insurance business, as prescribed by law. Every insurer, which has been writing such insurance in this Commonwealth for three years, shall furnish to the Department of Revenue a statement of all such items, in the form prescribed by it, for each of the preceding three calendar years. An insurer, which has not been writing such marine insurance for three years, shall furnish to the Department of Revenue a statement of all said items for each of the calendar years during which it has written marine insurance. Every such insurer, at the time of making the report required by this section, shall assess its tax upon underwriting profits as provided by law.
72 P.S. § 715