REMEDIES EXCLUSIVE.
Tex. TAX Code § 42.09.
in effect(a) Except as provided by Subsection (b) of this section, procedures prescribed by this title for adjudication of the grounds of protest authorized by this title are exclusive, and a property owner may not raise any of those grounds:
(1) in defense to a suit to enforce collection of delinquent taxes; or
(2) as a basis of a claim for relief in a suit by the property owner to arrest or prevent the tax collection process or to obtain a refund of taxes paid.
(b) A person against whom a suit to collect a delinquent property tax is filed may plead as an affirmative defense:
(1) if the suit is to enforce personal liability for the tax, that the defendant did not own the property on which the tax was imposed on January 1 of the year for which the tax was imposed; or
(2) if the suit is to foreclose a lien securing the payment of a tax on real property, that the property was not located within the boundaries of the taxing unit seeking to foreclose the lien on January 1 of the year for which the tax was imposed.
(c) For purposes of this section, "suit" includes a counterclaim, cross-claim, or other claim filed in the course of a lawsuit.
SUBCHAPTER B. REVIEW BY DISTRICT COURT