Texas Property Code - PROP § 221.042. Notice; Refund

(a) If a purchaser elects to cancel a purchase contract under Section 221.041, the purchaser may do so by hand-delivering notice of cancellation to the developer, by mailing notice by prepaid United States mail to the developer or to the developer's agent for service of process, or by providing notice by overnight common carrier delivery service to the developer or the developer's agent for service of process.

(b) Cancellation is without penalty, and all payments made by the purchaser before cancellation must be refunded on or before the 30th day after the date on which the developer receives a timely notice of cancellation or on or before the fifth day after the date the developer receives good funds from the purchaser, whichever is later.