Tex. Natural Resources Code § 161.320: LATE PAYMENTS; DEFAULT INTEREST RATE.

(a) The board may impose charges for late payments.

(b) In addition to charging for late payments under Subsection (a), the board may set and impose a default rate of interest on:

(1) the past due amounts; or

(2) the entire unpaid balance.

Acts 1977, 65th Leg., p. 2672, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977. Amended by Acts 1985, 69th Leg., ch. 798, Sec. 14, eff. Sept. 1, 1985; Acts 2003, 78th Leg., ch. 674, Sec. 9, eff. Sept. 1, 2003.