16 Pa. Stat. § 4904
The controller shall keep a full and regular set of books in detail, by double entry, of all the fiscal operations of the county, embracing as many accounts, under appropriate titles, as may be necessary to show distinctly and separately all the property of the county, its receipts and expenditures, and all debts and accounts due by the county officers or others, and the amount raised from each source of revenue, and the expenditures in detail, and classified by reference to the objects thereof. He shall prescribe the form and manner of keeping the books and papers used by each of the officers of the county in connection with the fiscal affairs of the county. Where the controller prescribes a new system of accounting as to the fiscal affairs of the county officers, it shall be subject to the approval of the county commissioners.
16 P.S. § 4904