(1) for all taxes collected and paid over;

(2) for all uncollected, nonlienable installments carried forward and certified for collection by the elected tax collector in accordance with section 11;¹

(3) for all unpaid taxes certified by the tax collector to the taxing district for collection as delinquent taxes as authorized by law;

(4) for unpaid taxes resulting from an interim assessment where, as of December 31, taxes remain unpaid and less than four months have elapsed since the date of the tax notice;

(5) for all unpaid taxes upon real property, which real property shall have been returned to the county commissioners as provided by law, or shall have been certified to the taxing district, or its solicitor, for the entry of liens in the office of the prothonotary; and

(6) in the case of occupation, poll and per capita taxes, for taxes accounted for by exonerations, which shall be granted by the taxing district upon oath or affirmation that he has complied with section twenty of this act.

In all taxing districts which have authorized installment payments to be made after December 31 of the year in which taxes are levied, all unpaid installments of taxes upon real property shall be certified by the elected tax collector to the taxing district, together with a proper description of the property upon which the same is levied, at the time of complete and final settlement. All unpaid installments so certified to the taxing district shall be collected by the elected tax collector in accordance with section 11.

Upon final and complete settlement of a tax duplicate, a tax collector shall take an oath or affirmation in writing and subscribed by the tax collector, that he has made a true and just return of all taxes collected by him. Such oath or affirmation shall be administered by the officer of the taxing district empowered to make settlement, who shall have power to administer the same, and shall be filed with such officer.

(b)(1) The final accounts and monthly or other periodic returns and payments of a tax collector for county taxes collected for a county of the third, fourth, fifth, sixth, seventh or eighth class in counties with an elected controller may be audited by the controller. If the controller does not conduct this audit, clause (2) shall apply.

(2) The provisions of this clause shall apply to all taxing districts except counties in which an audit is conducted by a county controller in accordance with clause (1). (i) The tax collector's final accounts and records, monthly or other periodic returns and payments and duplicates shall be audited annually by the controller or auditors of the taxing district or, at the request of the taxing district, by an independent certified public accountant or public accountant. (ii) If the audit is conducted by the controller or auditors of the taxing district, the audit shall be conducted in accordance with the laws of the Commonwealth applicable to the taxing district. (iii) If the audit is conducted by a certified public accountant or public accountant, the audit shall be conducted in accordance with generally accepted auditing standards.

(3) Nothing in this act or any other law shall prohibit local taxing districts from cooperating in conducting a simultaneous audit of any tax collector serving the taxing districts. Taxing districts may enter into agreements whereby the elected auditor or controller of one taxing district or a designated certified public accountant or public accountant may conduct a simultaneous audit on behalf of each taxing district.