The answer depends on the nature of the conversation and whether an employee is nonexempt. Let’s assume we are talking only about nonexempt employees here in this article. A non-exempt employee is generally an employee that does not have a legal exemption for minimum wage or overtime for all hours worked. Consequently, employers must compensate these employees for all hours worked, which means the time during which an employee is subject to the control of an employer and includes all the time the employee is instructed to or permitted to work. What constitutes sufficient control by an employer is a question for the jury.
Employers probably may lawfully text an employee about information that is only incidental to the employee’s job duties without having to compensate the employee for the time spent engaging in the text conversation. For example, if an employer simply texts an employee on Sunday night at 6pm, outside regular scheduled working hours, asking what time the employee is going into work the next morning, then it would probably be unreasonable to conclude that the employee was under the control of the employer. Also, an employer can text with an employee about things unrelated to work without having to pay the employee for the time because that probably will not be construed as exercising control over the employee.
On the other hand, if an employer requires an employee to respond with an immediate action or perform regular job duties for the benefit of the employer, then sufficient control probably exists to require an employer to compensate the employee. For example, if a supervisor texts an employee on a Sunday night at 6pm, outside regular working hours, asking an employee to draft and send an agenda that night for a meeting scheduled the next day, then the employer must pay for all time worked, probably including the text messages discussing the assignment.
From the perspective of an employer, best practices are probably to limit discussing their employees’ work tasks to discussions during normal work hours, and to pay employees for all time worked regardless of schedule or location.
IWC Orders 1-16: Section 2; CA Division of Labor Standards Enforcement Policies and Interpretation Manual 46.1