(a) In a county in which the county treasurer is compensated on a fee basis, the treasurer is entitled to the following commissions for receiving and paying out money for the county:
(1) for money other than school funds, a percentage set by order of the commissioners court not to exceed 2-1/2 percent of the money received and a percentage set by order of the court not to exceed 2-1/2 percent of the money paid out; and
(2) for school funds, one-half percent of the money received and one-half percent of the money paid out.
(b) A commission earned under Subsection (a)(2) is payable from the available school fund of the county.
(c) A county treasurer may not receive a commission under this section for money received from the treasurer's predecessor or money paid to the treasurer's successor. A county treasurer may not receive a commission under Subsection (a)(2) for transferring money.