The Fair Labor Standards Act requires the vast majority of employers in this country to pay overtime (one and one-half times a non-exempt employee's regular hourly rate of compensation) for any hours worked over 40 in any given workweek. For example, an employee with a regular rate of $20 per hour would be entitled to overtime compensation at the rate of $30 per hour. Very commonly, employers attempt to control costs by banning overtime altogether or by requiring non-exempt employees (i.e. entitled to overtime compensation) to obtain advance supervisory approval prior to working overtime. Such policies are certainly an effective way to regulate and maintain some degree of control over the hours worked by non-exempt employees and the corresponding overhead associated with paying overtime compensation.
Banning overtime or requiring advance approval does NOT relieve employers from the obligation to pay overtime compensation to non-exempt employees who work more than 40 hours per week in defiance of corporate policy. In other words, if a non-exempt employee works more than 40 hours in any given work week, the employee is entitled to receive overtime compensation for all such hours. Employers can discipline or even terminate policy offenders, but the obligation to pay overtime remains.