Texas Tax Code - TAX § 42.031. Right of Appeal by Taxing Unit

(a) A taxing unit is entitled to appeal an order of the appraisal review board determining a challenge by the taxing unit.

(b) A taxing unit may not intervene in or in any other manner be made a party, whether as defendant or otherwise, to an appeal of an order of the appraisal review board determining a taxpayer protest under Subchapter C, Chapter 41,  1 if the appeal was brought by the property owner.