Tex. Lab. Code § 409.002
Failure to notify an employer as required by Section 409.001(a) relieves the employer and the employer's insurance carrier of liability under this subtitle unless:
Acts 1993, 73rd Leg., ch. 269, Sec. 1, eff. Sept. 1, 1993.
Acts 2005, 79th Leg., Ch. 265 (H.B. 7), Sec. 3.134, eff. September 1, 2005.