At a hearing on a petition filed under Section 29.002, the petitioner must prove by clear and convincing evidence that:
(1) the petitioner has paid the defendant's share of ad valorem taxes imposed on the property that is the subject of the petition for any three years in a five-year period or, in the case of a nonprofit organization, the petitioner has paid the defendant's share of ad valorem taxes imposed on the property that is the subject of the petition for any two years in a three-year period;
(2) before the date on which the petition was filed the petitioner made a demand that the defendant reimburse the petitioner for the amount of the defendant's share of ad valorem taxes imposed on the property paid by the petitioner; and
(3) the defendant has not reimbursed the petitioner more than half of the amount of money the petitioner paid on the defendant's behalf for the defendant's share of ad valorem taxes imposed on the property.
Official text of the Texas Property Code as published by the Texas Legislative Council.