POSTPONEMENT OF DELINQUENCY DATE.

(a) If a tax bill is mailed after January 10, the delinquency date provided by Section 31.02 of this code is postponed to the first day of the next month that will provide a period of at least 21 days after the date of mailing for payment of taxes before delinquent unless the taxing unit has adopted the discounts provided by Section 31.05(c) of this code, in which case the delinquency date is determined by Subsection (d) of this section.

(a-1) If a tax bill is mailed that includes taxes for one or more preceding tax years because the property was erroneously omitted from the tax roll in those tax years, the delinquency date provided by Section 31.02 is postponed to February 1 of the first year that will provide a period of at least 180 days after the date the tax bill is mailed in which to pay the taxes before they become delinquent.

(b) If the delinquency date is postponed as provided by this section, the assessor who mails the bills shall notify the governing body of each taxing unit whose taxes are included in the bills of the postponement.

(c) A discount adopted under Section 31.05(b) does not apply to taxes that are calculated too late for it to be available.

(d) If a taxing unit mails its tax bills after September 30 and adopts the discounts provided by Section 31.05(c) of this code, the delinquency date is postponed to the first day of the next month following the fourth full calendar month following the date the tax bills were mailed.

(e) If the delinquency date for a tax is postponed under Subsection (a) or (a-1), that postponed delinquency date is the date on which penalties and interest begin to be incurred on the tax as provided by Section 33.01.