Texas Tax Code - TAX § 31.07. Certain Payments Accepted

(a) A person may pay the tax imposed on any one property without simultaneously paying taxes imposed on other property he owns.

(b) A collector shall accept payment of the tax imposed on a property by a taxing unit that has adopted the discounts under Section 31.05 of this code separately from taxes imposed on that property by other taxing units using the same collector, even if the taxes are included in the same bill.  The collector may adopt a policy of accepting separate payments in other circumstances.  If the tax paid is included in the same bill as other taxes that are not paid, the collector shall send a revised bill or receipt to reflect the tax payment, if a discount applies to the payment, and may send a revised bill or receipt to reflect the tax payment in other circumstances.  The sending of a revised bill does not affect the date on which the unpaid taxes become delinquent.

(c) A collector may adopt a policy of accepting partial payments of property taxes.  A payment option provided by Section 31.03 of this code or a discount adopted under Section 31.05 of this code does not apply to any portion of a partial payment.  If a collector accepts a partial payment on a tax bill that includes taxes for more than one taxing unit, the collector shall allocate the partial payment among all the taxing units included in the bill in proportion to the amount of tax included in the bill for each taxing unit, unless the collector under Subsection (b) has adopted a policy of accepting payments of a taxing unit's taxes separate from the taxes of other taxing units included in the same bill and the taxpayer directs that the partial payment be allocated in specific amounts to one or more specific taxing units. Acceptance of a partial payment does not affect the date that the tax becomes delinquent, but the penalties and interest provided by Section 33.01 of this code are incurred only by the portion of a tax that remains unpaid on the date the tax becomes delinquent.

(d) Notwithstanding Subsection (c), a collector shall accept a partial payment of property taxes on a tax bill that includes taxes for more than one taxing unit if one or more of the taxing units has adopted the discounts under Section 31.05 of this code, the taxpayer directs that the partial payment be allocated first to the payment of the taxes owed one or more of the taxing units that have adopted the discounts, and the amount of the payment is equal to or greater than the amount of the taxes owed the taxing units designated by the taxpayer.