Texas Estates Code - EST § 505.004. Filing Requirements; Designation

(1) a copy of the fiduciary's charter, articles of incorporation or of association, and all amendments to those documents, certified by the fiduciary's secretary under the fiduciary's corporate seal;

(2) a properly executed written instrument that by the instrument's terms is of indefinite duration and irrevocable, appointing the secretary of state and the secretary of state's successors as the fiduciary's agent for service of process on whom notices and processes issued by a court of this state may be served in an action or proceeding relating to a trust, estate, fund, or other matter within this state with respect to which the fiduciary is acting in a fiduciary capacity, including the acts or defaults of the fiduciary with respect to that trust, estate, or fund; and

(3) a written certificate of designation specifying the name and address of the officer, agent, or other person to whom the secretary of state shall forward notices and processes described by Subdivision (2).