1. In addition to the fees collected on all delinquent and back taxes by any treasurer ex officio collector pursuant to the provisions of this chapter and chapter 50, such ex officio collector shall collect an additional two percent on all delinquent and back taxes and these additional fees shall be transmitted monthly for deposit into the tax maintenance fund pursuant to the provisions of section 54.323 and used for additional administration and operation costs for the office of treasurer ex officio collector. Any costs shall include, but shall not be limited to, those costs that require any additional out-of-pocket expense by the office of treasurer ex officio collector and it may include reimbursement to county general revenue for the salaries of employees of the office of treasurer ex officio collector for hours worked and any other expenses necessary to conduct and execute the duties and responsibilities of such office.

2. The tax maintenance fund may also be used by the treasurer ex officio collector for training, purchasing new or upgrading information technology, equipment or other essential administrative expenses necessary to carry out the duties and responsibilities of the office of treasurer ex officio collector, including anything necessarily pertaining thereto.

3. The treasurer ex officio collector has the sole responsibility for all expenditures made from the tax maintenance fund and shall approve all expenditures from such fund. All such expenditures from the tax maintenance fund shall not be used to substitute for or subsidize any allocation of county general revenue for the operation of the office of treasurer ex officio collector.

4. The tax maintenance fund may be audited by the appropriate auditing agency. Any unexpended balance shall be left in the tax maintenance fund, to accumulate from year to year with interest.