Tex. Tax Code § 33.07

Sec. 33.07. ADDITIONAL PENALTY FOR COLLECTION COSTS FOR TAXES DUE BEFORE JUNE 1. (a) A taxing unit or appraisal district may provide, in the manner required by law for official action by the body, that taxes that become delinquent on or after February 1 of a year but not later than May 1 of that year and that remain delinquent on July 1 of the year in which they become delinquent incur an additional penalty to defray costs of collection, if the unit or district or another unit that collects taxes for the unit has contracted with an attorney pursuant to Section 6.30. The amount of the penalty may not exceed the amount of the compensation specified in the contract with the attorney to be paid in connection with the collection of the delinquent taxes.

(b) A tax lien attaches to the property on which the tax is imposed to secure payment of the penalty.

(c) If a penalty is imposed pursuant to this section, a taxing unit may not recover attorney's fees in a suit to collect delinquent taxes subject to the penalty.

(d) If a taxing unit or appraisal district provides for a penalty under this section, the collector shall deliver a notice of delinquency and of the penalty to the property owner at least 30 and not more than 60 days before July 1.