(a) If a taxpayer applies to the tax collector of a taxing unit for a refund of an overpayment or erroneous payment of taxes, the collector for the unit determines that the payment was erroneous or excessive, and the auditor for the unit agrees with the collector’s determination, the collector shall refund the amount of the excessive or erroneous payment from available current tax collections or from funds appropriated by the unit for making refunds. However, the collector may not make the refund unless:
(1) in the case of a collector who collects taxes for one taxing unit, the governing body of the taxing unit also determines that the payment was erroneous or excessive and approves the refund if the amount of the refund exceeds:
(A) $5,000 for a refund to be paid by a county with a population of 2.5 million or more; or
(B) $500 for a refund to be paid by any other taxing unit; or
(2) in the case of a collector who collects taxes for more than one taxing unit, the governing body of the taxing unit that employs the collector also determines that the payment was erroneous or excessive and approves the refund if the amount of the refund exceeds:
(A) $5,000 for a refund to be paid by a county with a population of 2.5 million or more; or
(B) $2,500 for a refund to be paid by any other taxing unit.
(b) A taxing unit that determines a taxpayer is delinquent in ad valorem tax payments on property other than the property for which liability for a refund arises or for a tax year other than the tax year for which liability for a refund arises may apply the amount of an overpayment or erroneous payment to the payment of the delinquent taxes if the taxpayer was the sole owner of the property:
(1) for which the refund is sought on January 1 of the tax year in which the taxes that were overpaid or erroneously paid were assessed; and
(2) on which the taxes are delinquent on January 1 of the tax year for which the delinquent taxes were assessed.

(c) Except as provided by Subsection (c-1), an application for a refund must be made within three years after the date of the payment or the taxpayer waives the right to the refund. A taxpayer may apply for a refund by filing:
(1) an application on a form prescribed by the comptroller by rule; or
(2) a written request that includes information sufficient to enable the collector and the auditor for the taxing unit and, if applicable, the governing body of the taxing unit to determine whether the taxpayer is entitled to the refund.
(c-1) The governing body of the taxing unit may extend the deadline provided by Subsection (c) for a single period not to exceed two years on a showing of good cause by the taxpayer.
(d) The collector for a taxing unit shall provide a copy of the refund application form without charge on request of a taxpayer or a taxpayer’s representative.
(e) An application for a refund must:
(1) include an affirmation by the taxpayer that the information in the application is true and correct; and
(2) be signed by the taxpayer.
(f) This subsection applies only to a refund that is required to be approved by the governing body of a taxing unit. The presiding officer of the governing body of the taxing unit is not required to sign the application for the refund or any document accompanying the application to indicate the governing body’s approval or disapproval of the refund. The collector for the taxing unit shall indicate on the application whether the governing body approved or disapproved the refund and the date of the approval or disapproval.
(g) If a taxpayer submits a payment of taxes that exceeds by $5 or more the amount of taxes owed for a tax year to a taxing unit, the collector for the taxing unit, without charge, shall mail to the taxpayer or the taxpayer’s representative a written notice of the amount of the overpayment accompanied by a refund application form.
(h) This section does not apply to an overpayment caused by a change of exemption status or correction of a tax roll, including an overpayment received after a correction of a tax roll as a result of an appeal under Chapter 42. Such an overpayment is covered by § 26.15 or 42.43, as applicable.
(i) Notwithstanding the other provisions of this section, in the case of an overpayment or erroneous payment of taxes submitted by a taxpayer to a collector who collects taxes for one or more taxing units one of which is a county with a population of 2.5 million or more:
(1) a taxpayer is not required to apply to the collector for the refund to be entitled to receive the refund if the amount of the refund is at least $5 but does not exceed $5,000; and
(2) the collector is not required to comply with Subsection (g) unless the amount of the payment exceeds by more than $5,000 the amount of taxes owed for a tax year to a taxing unit for which the collector collects taxes.
(j) If the collector for a taxing unit does not respond to an application for a refund on or before the 90th day after the date the application is filed with the collector, the application is presumed to have been denied.
(k) Not later than the 60th day after the date the collector for a taxing unit denies an application for a refund, the taxpayer may file suit against the taxing unit in district court to compel the payment of the refund. If the collector collects taxes for more than one taxing unit, the taxpayer shall join in the suit each taxing unit on behalf of which the collector denied the refund. If the taxpayer prevails in the suit, the taxpayer may be awarded:
(1) costs of court; and
(2) reasonable attorney’s fees in an amount not to exceed the greater of:
(A) $1,500; or
(B) 30 percent of the total amount of the refund determined by the court to be due.