(a) A delinquent tax incurs a penalty of six percent of the amount of the tax for the first calendar month it is delinquent plus one percent for each additional month or portion of a month the tax remains unpaid prior to July 1 of the year in which it becomes delinquent. However, a tax delinquent on July 1 incurs a total penalty of twelve percent of the amount of the delinquent tax without regard to the number of months the tax has been delinquent. A delinquent tax continues to incur the penalty provided by this subsection as long as the tax remains unpaid, regardless of whether a judgment for the delinquent tax has been rendered.
(b) If a person who exercises the split-payment option provided by § 31.03 of this code fails to make the second payment before July 1, the second payment is delinquent and incurs a penalty of twelve percent of the amount of unpaid tax.

(c) A delinquent tax accrues interest at a rate of one percent for each month or portion of a month the tax remains unpaid. Interest payable under this section is to compensate the taxing unit for revenue lost because of the delinquency. A delinquent tax continues to accrue interest under this subsection as long as the tax remains unpaid, regardless of whether a judgment for the delinquent tax has been rendered.
(d) In lieu of the penalty imposed under Subsection (a), a delinquent tax incurs a penalty of 50 percent of the amount of the tax without regard to the number of months the tax has been delinquent if the tax is delinquent because the property owner received an exemption under:
(1) § 11.13 and the chief appraiser subsequently cancels the exemption because the residence was not the principal residence of the property owner and the property owner received an exemption for two or more additional residence homesteads for the tax year in which the tax was imposed;
(2) § 11.13(c) or (d) for a person who is 65 years of age or older and the chief appraiser subsequently cancels the exemption because the property owner was younger than 65 years of age; or
(3) § 11.13(q) and the chief appraiser subsequently cancels the exemption because the property owner was younger than 55 years of age when the property owner’s spouse died.
(e) A penalty imposed under Subsection (d) does not apply if:
(1) the exemption was granted by the appraisal district or board and not at the request or application of the property owner or the property owner’s agent; or
(2) at any time before the date the tax becomes delinquent, the property owner gives to the chief appraiser of the appraisal district in which the property is located written notice of circumstances that would disqualify the owner for the exemption.
(f) Notwithstanding the other provisions of this section, a delinquent tax for which a person defers payment under § 31.02(b) that is not paid on or before the date the deferral period prescribed by that subsection expires:
(1) accrues interest at a rate of six percent for each year or portion of a year the tax remains unpaid; and
(2) does not incur a penalty.