Tex. Tax Code § 11.45

(a) The chief appraiser shall determine separately each applicant's right to an exemption. After considering the application and all relevant information, the chief appraiser shall, as soon as practicable but not later than the 90th day after the later of the date the applicant first qualifies for the exemption or the date the applicant provides to the chief appraiser the information necessary for the chief appraiser to determine the applicant's right to the exemption, as the law and facts warrant:

(1) approve the application and allow the exemption;

(2) modify the exemption applied for and allow the exemption as modified;

(3) disapprove the application and request additional information from the applicant in support of the claim; or

(4) deny the application.

(b) If the chief appraiser requires additional information from an applicant, the chief appraiser shall, as soon as practicable but not later than the 30th day after the date the application is filed with the chief appraiser, deliver a written notice to the applicant specifying the additional information the applicant must provide to the chief appraiser before the chief appraiser can determine the applicant's right to the exemption. The applicant must furnish the information not later than the 30th day after the date of the request or the application is denied. However, for good cause shown the chief appraiser may extend the deadline for furnishing the information by written order for a single period not to exceed 15 days.

(c) The chief appraiser shall determine the validity of each application for exemption filed with him before he submits the appraisal records for review and determination of protests as provided by Chapter 41 of this code.

(d) If the chief appraiser modifies or denies an application, the chief appraiser shall deliver a written notice of the modification or denial to the applicant not later than the fifth day after the date the chief appraiser makes the determination. The notice must state and fully explain each reason the chief appraiser modified or denied the application. The notice must include a brief explanation of the procedures for protesting the modification or denial.

(e) If the chief appraiser approves, modifies, or denies an application for an exemption under Section 11.35, the chief appraiser shall deliver a written notice of the approval, modification, or denial to the applicant not later than the fifth day after the date the chief appraiser makes the determination. The notice must include the damage assessment rating assigned by the chief appraiser to each item of qualified property that is the subject of the application and a brief explanation of the procedures for protesting the chief appraiser's determination. If the chief appraiser modifies or denies the application, the notice must state and fully explain each reason the chief appraiser modified or denied the application. The notice required under this subsection is in lieu of any notice that would otherwise be required under Subsection (d).