Under The Fair Labor Standards Act, or FLSA (F-L-S-A), employers are legally allowed to require employees to be on-call. If companies choose to do so, FLSA regulations require that employees be properly compensated for their working time. Compensation for on-call time can include overtime pay or extra time off. Depending on the circumstances, however, employers don't have to compensate employees for all on-call time. For example, if an employee carries a pager or a cell phone and is free to do whatever he or she wants to do while on-call, an employer usually doesn't have to pay for it. In the same manner, if an employee is required to remain on-call on the employer's premises, he or she must be compensated for the on-call time. The factors which can affect whether on-call time is paid for include the length and flexibility of the on-call period, the frequency of calls, the geographic restrictions imposed, whether the employee has to perform a specific duty, and the employee's ability to engage in personal activities. Courts generally regulate on-call time in two ways. On-call time that an employee can control and use for personal enjoyment or benefit isn't counted as payable time. Conversely, on-call time which is controlled by the employer and restricts an employee's personal activities is considered payable time. Furthermore, as long as the employees are paid at least the minimum amount required under federal wage and hour regulations, employers are permitted to pay a different hourly rate for on-call time than they do for regular work time.