Tex. Finance Code § 305.103

(a) A creditor is not liable to an obligor for a violation of this subtitle if:

(1) not later than the 60th day after the date the creditor actually discovered the violation, the creditor corrects the violation as to that obligor by taking any necessary action and making any necessary adjustment, including the payment of interest on a refund, if any, at the applicable rate provided for in the contract of the parties; and

(2) the creditor gives written notice to the obligor of the violation before the obligor gives written notice of the violation or files an action alleging the violation.

(b) For the purposes of Subsection (a), a violation is actually discovered at the time of the discovery of the violation in fact and not at the time when an ordinarily prudent person, through reasonable diligence, could or should have discovered or known of the violation. Actual discovery of a violation in one transaction may constitute actual discovery of the same violation in other transactions if the violation is of such a nature that it would necessarily be repeated and would be clearly apparent in the other transactions without the necessity of examining all the other transactions.

(c) For purposes of Subsection (a), written notice is given when the notice is delivered to the person or to the person's authorized agent or attorney of record personally, by telecopier, or by United States mail to the address shown on the most recent documents in the transaction. Deposit of the notice as registered or certified mail in a postage paid, properly addressed wrapper in a post office or official depository under the care and custody of the United States Postal Service is prima facie evidence of the delivery of the notice to the person to whom the notice is addressed.