Tex. Prop. Code § 240.103
In the case of an interest in a testamentary trust:
(3) if no trustee or personal representative is then serving, a disclaimer must be filed in the official public records of any county in which the decedent:
Added by Acts 2015, 84th Leg., R.S., Ch. 562 (H.B. 2428), Sec. 15, eff. September 1, 2015.