(a) The state may bring a counterclaim in a suit under this subchapter if:
(1) the counterclaim relates to taxes imposed under the same statute and during the same period as the taxes that are the subject of the suit; and
(2) the counterclaim is filed not later than the 30th day before the date set for trial on the merits of the suit.
(b) The state is not required to make an assessment of the taxes subject to the counterclaim under any other statute, and the period of limitation applicable to an assessment of the taxes does not apply to a counterclaim brought under this section.
Official text of the Texas Tax Code as published by the Texas Legislative Council.