California Code, Labor Code - LAB § 1409

(1) “Call center” means a facility or other operation where employees, as their primary function, receive telephone calls or other electronic communication for the purpose of providing customer service or other related functions.

(2) “Call center employer” means an employer of a covered establishment, as those terms are defined in Section 1400.5, who operates a call center.

(3) “Relocation of a call center” includes when the employer intends to move its call center, or one or more facilities or operating units within a call center comprising at least 30 percent of the call center's or operating unit's total volume when measured against the average call volume for the previous 12 months, or substantially similar operations to a foreign country.