Tex. Family Code § 8.059

(a) The court may enforce by contempt against the obligor:

(1) the court's maintenance order; or

(2) an agreement for periodic payments of spousal maintenance under the terms of this chapter voluntarily entered into between the parties and approved by the court.

(a-1) The court may not enforce by contempt any provision of an agreed order for maintenance that exceeds the amount of periodic support the court could have ordered under this chapter or for any period of maintenance beyond the period of maintenance the court could have ordered under this chapter.

(b) On the suit to enforce by an obligee, the court may render judgment against a defaulting party for the amount of arrearages after notice by service of citation, answer, if any, and a hearing finding that the defaulting party has failed or refused to comply with the terms of the order. The judgment may be enforced by any means available for the enforcement of judgment for debts, including by an order or writ of withholding and a maintenance qualified domestic relations order under Subchapter H.

(c) It is an affirmative defense to an allegation of contempt of court or the violation of a condition of probation requiring payment of court-ordered maintenance that the obligor:

(1) lacked the ability to provide maintenance in the amount ordered;

(2) lacked property that could be sold, mortgaged, or otherwise pledged to raise the funds needed;

(3) attempted unsuccessfully to borrow the needed funds; and

(4) did not know of a source from which the money could have been borrowed or otherwise legally obtained.

(d) The issue of the existence of an affirmative defense does not arise until pleaded. An obligor must prove the affirmative defense by a preponderance of the evidence.

(e) Repealed by Acts 2011, 82nd Leg., R.S., Ch. 486, Sec. 9(3), eff. September 1, 2011.