Tex. Est. Code § 1157.052
The failure of a guardian of the estate to endorse on or attach to a claim presented to the guardian the memorandum required by Section 1157.051 or, not later than the 30th day after the date a claim is presented, to allow or reject the claim or portion of the claim constitutes a rejection of the claim. If the claim is later established by suit:
Added by Acts 2011, 82nd Leg., R.S., Ch. 823 (H.B. 2759), Sec. 1.02, eff. January 1, 2014.