Tex. Local Government Code § 141.008

(a) The governing body of a municipality with a population of more than 10,000 may deduct from a municipal employee's monthly salary or wages an amount requested in writing by the employee in payment of membership dues to a bona fide employees' association named by the employee.

(a-1) The governing body shall make the payroll deduction described by Subsection (a) if requested in writing by employees who are fire protection personnel as defined by Section 419.021, Government Code, if the municipality receives revenue from the state, and if the municipality permits deductions for purposes other than charity, health insurance, taxes, or other purposes for which the municipality is required by law to permit a deduction.

(a-2) The governing body shall make the payroll deduction described by Subsection (a) if:

(1) requested in writing by employees who:

(A) are peace officers as defined by Article 2A.001, Code of Criminal Procedure; and

(B) are not members of a police department covered by a collective bargaining agreement or meet-and-confer agreement entered into under this code; and

(2) the municipality permits deductions for purposes other than charity, health insurance, taxes, or other purposes for which the municipality is required by law to permit a deduction.

(b) Participation in the payroll deduction program by a municipal employee who is on active full-time duty is voluntary.

(c) An employee's written request must:

(1) be set out in a form prescribed and provided by the municipal treasurer or comptroller;

(2) state the amount to be deducted each month; and

(3) direct the municipal treasurer or comptroller to transfer the deducted funds to the designated employees' association.

(d) The amount deducted each month may not exceed the amount stated in the written request. However, the governing body of a municipality having a program under this section may impose and collect an administrative fee from each participating employee in addition to the membership dues that are withheld. The fee must be a reasonable amount to reimburse the municipality for the administrative costs of collecting, accounting for, and disbursing the membership dues.

(e) A request under this section remains in effect until the municipal treasurer or comptroller receives a written notice of revocation in a form prescribed and provided by the treasurer or comptroller and filed by the employee.