Tex. Agriculture Code § 12.023

The department by rule shall adopt a system under which registrations or licenses required by the department, including licenses issued under Chapter 1951, Occupations Code, expire on various dates during the year. The department may increase or decrease the term of an initial or renewal license or registration so that all licenses held by a person or a group of license holders expire on the same date. For the period in which the registration or license expiration date is changed, registration or license fees shall be prorated on a monthly basis so that each registrant or licensee pays only that portion of the fee that is allocable to the number of months during which the registration or license is valid. On the next renewal of the registration or license, the total renewal fee is payable.