Tex. Civil Practice and Remedies Code § 73.058

(a) If a defendant in an action under this subchapter intends to rely on a timely and sufficient correction, clarification, or retraction, the defendant's intention to do so, and the correction, clarification, or retraction relied on, must be stated in a notice served on the plaintiff on the later of:

(1) the 60th day after service of the citation; or

(2) the 10th day after the date the correction, clarification, or retraction is made.

(b) A correction, clarification, or retraction is timely and sufficient unless the plaintiff challenges the timeliness or sufficiency not later than the 20th day after the date notice under Subsection (a) is served. If a plaintiff challenges the timeliness or sufficiency, the plaintiff must state the challenge in a motion to declare the correction, clarification, or retraction untimely or insufficient served not later than the 30th day after the date notice under Subsection (a) is served on the plaintiff or the 30th day after the date the correction, clarification, or retraction is made, whichever is later.

(c) If a defendant intends to challenge the sufficiency or timeliness of a request for a correction, clarification, or retraction, the defendant must state the challenge in a motion to declare the request insufficient or untimely served not later than the 60th day after the date of service of the citation.

(d) Unless there is a reasonable dispute regarding the actual contents of the request for correction, clarification, or retraction, the sufficiency and timeliness of a request for correction, clarification, or retraction is a question of law. At the earliest appropriate time before trial, the court shall rule, as a matter of law, whether the request for correction, clarification, or retraction meets the requirements of this subchapter.