Cal. Rev. & Tax. Code § 41128

The department shall enforce the provisions of this part and may prescribe, adopt, and enforce rules and regulations relating to the administration and enforcement of this part. The department shall not prescribe, adopt, or enforce any rule or regulation that has the effect, directly or indirectly, of altering the terms and conditions of service of a service supplier serving the general public, other than the imposition of the surcharges.