Tex. Finance Code § 345.156: WHEN CHARGING OF TIME PRICE DIFFERENTIAL PROHIBITED.

A time price differential may not be charged for a billing cycle of a retail charge agreement that provides for a time price differential under this subchapter if:

(1) the payments received for the agreement and amounts credited during the billing cycle that are attributable to amounts included in the balance owed at the end of the preceding billing cycle equal or exceed the balance owed under the agreement at the end of the preceding billing cycle; or

(2) a balance is not owed at the end of the preceding billing cycle.

Acts 1997, 75th Leg., ch. 1008, Sec. 1, eff. Sept. 1, 1997.