Wash. Rev. Code § 49.37.130
(1) If the employer has the information in the employer's records, the employer must provide to the exclusive bargaining representative the following information for each employee in an appropriate bargaining unit:
(b) The employee's contact information, including:
(2) The employer must provide the information to the exclusive bargaining representative in an editable digital file format:
[ 2025 c 106 s 13.]