Texas Tax Code - TAX § 41.62. Service and Enforcement of Subpoena

(a) A sheriff or constable shall serve a subpoena issued as provided by this subchapter.

(b) If the person to whom a subpoena is directed fails to comply, the issuing board or the party requesting the subpoena may bring suit in the district court to enforce the subpoena.  If the district court determines that good cause exists for issuance of the subpoena, the court shall order compliance.  The district court may modify the requirements of a subpoena that the court determines are unreasonable.  Failure to obey the order of the district court is punishable as contempt.

(c) The county attorney or, if there is no county attorney, the district attorney shall represent the board in a suit to enforce a subpoena.