Texas Transportation Code - TRANSP § 451.416. Emissions Tax Year

(a) A motor vehicle emissions tax year begins on April 1 of each year and is divided into quarters.

(b) A tax accruing during the second quarter of the tax year is three-fourths of the amount of the annual tax. A tax accruing during the third quarter is one-half of the amount of the annual tax. A tax accruing during the fourth quarter is one-fourth of the amount of the annual tax.