Tex. Tax Code § 6.28

(a) Before beginning to perform the duties of office, a person elected or appointed as county assessor-collector must give bonds to the state and to the county, conditioned on the faithful performance of the person's duties as assessor-collector.

(b) The bond for state taxes must be payable to the governor and his successors in office in an amount equal to five percent of the net state collections from motor vehicle sales and use taxes and motor vehicle registration fees in the county during the year ending August 31 preceding the date bond is given, except that the amount of bond may not be less than $2,500 or more than $100,000. To be effective, the bond must be approved by the commissioners court and the state comptroller of public accounts.

(c) The bond for county taxes must be payable to the commissioners court in an amount equal to 10 percent of the total amount of county taxes imposed in the preceding tax year, except that the amount of the bond may not be less than $2,500 or more than $100,000, except as otherwise provided by this subsection. The commissioners court of a county with a population of 1.5 million or more by order may set the maximum amount of the bond in an amount greater than $100,000. To be effective, a bond under this subsection must be approved by the commissioners court.

(d) The state comptroller of public accounts or the commissioners court may require a new bond for state taxes at any time. The commissioners court may require a new bond for county taxes at any time. However, the total amount of state bonds or county bonds required of an assessor-collector may not exceed $100,000 at one time, except that in a county in which the commissioners court by order has set the maximum amount of the bond for county taxes in an amount greater than $100,000, the total amount of state bonds or county bonds required may not exceed that greater amount. The commissioners court shall suspend the assessor-collector from office and begin removal proceedings if the assessor-collector fails to give new bond within a reasonable time after demand.

(e) The assessor-collector's official oath and bonds for state and county taxes shall be recorded in the office of the county clerk, and the county judge shall submit the bond for state taxes to the state comptroller of public accounts.

(f) A county shall pay a reasonable premium for the assessor-collector's bonds for state and county taxes out of the county general revenue fund on presentation to the commissioners court of a bill for the premium authenticated as required by law for other claims against the county. A court of competent jurisdiction may determine the reasonableness of any amount claimed as premium.