Any person who willfully violates any of the provisions of section 215 of this title shall upon conviction thereof be subject to a fine of not more than $10,000, or to imprisonment for not more than six months, or both. No person shall be imprisoned under this subsection except for an offense committed after the conviction of such person for a prior offense under this subsection.
Any employer who violates the provisions of section 206 or section 207 of this title shall be liable to the employee or employees affected in the amount of their unpaid minimum wages, or their unpaid overtime compensation, as the case may be, and in an additional equal amount as liquidated damages. Any employer who violates the provisions of section 215(a)(3) or 218d of this title shall be liable for such legal or equitable relief as may be appropriate to effectuate the purposes of section 215(a)(3) or 218d of this title, including without limitation employment, reinstatement, promotion, and the payment of wages lost and an additional equal amount as liquidated damages. Any employer who violates section 203(m)(2)(B) of this title shall be liable to the employee or employees affected in the amount of the sum of any tip credit taken by the employer and all such tips unlawfully kept by the employer, and in an additional equal amount as liquidated damages. An action to recover the liability prescribed in the preceding sentences may be maintained against any employer (including a public agency) in any Federal or State court of competent jurisdiction by any one or more employees for and in behalf of himself or themselves and other employees similarly situated. No employee shall be a party plaintiff to any such action unless he gives his consent in writing to become such a party and such consent is filed in the court in which such action is brought. The court in such action shall, in addition to any judgment awarded to the plaintiff or plaintiffs, allow a reasonable attorney’s fee to be paid by the defendant, and costs of the action. The right provided by this subsection to bring an action by or on behalf of any employee, and the right of any employee to become a party plaintiff to any such action, shall terminate upon the filing of a complaint by the Secretary of Labor in an action under section 217 of this title in which (1) restraint is sought of any further delay in the payment of unpaid minimum wages, or the amount of unpaid overtime compensation, as the case may be, owing to such employee under section 206 or section 207 of this title by an employer liable therefor under the provisions of this subsection or (2) legal or equitable relief is sought as a result of alleged violations of section 215(a)(3) or 218d of this title.
The Secretary is authorized to supervise the payment of the unpaid minimum wages or the unpaid overtime compensation owing to any employee or employees under section 206 or section 207 of this title, and the agreement of any employee to accept such payment shall upon payment in full constitute a waiver by such employee of any right he may have under subsection (b) of this section to such unpaid minimum wages or unpaid overtime compensation and an additional equal amount as liquidated damages. The Secretary may bring an action in any court of competent jurisdiction to recover the amount of unpaid minimum wages or overtime compensation and an equal amount as liquidated damages. The right provided by subsection (b) to bring an action by or on behalf of any employee to recover the liability specified in the first sentence of such subsection and of any employee to become a party plaintiff to any such action shall terminate upon the filing of a complaint by the Secretary in an action under this subsection in which a recovery is sought of unpaid minimum wages or unpaid overtime compensation under sections 206 and 207 of this title or liquidated or other damages provided by this subsection owing to such employee by an employer liable under the provisions of subsection (b), unless such action is dismissed without prejudice on motion of the Secretary. Any sums thus recovered by the Secretary of Labor on behalf of an employee pursuant to this subsection shall be held in a special deposit account and shall be paid, on order of the Secretary of Labor, directly to the employee or employees affected. Any such sums not paid to an employee because of inability to do so within a period of three years shall be covered into the Treasury of the United States as miscellaneous receipts. In determining when an action is commenced by the Secretary of Labor under this subsection for the purposes of the statutes of limitations provided in section 6(a) of the Portal-to-Portal Act of 1947 [29 U.S.C. 255(a)], it shall be considered to be commenced in the case of any individual claimant on the date when the complaint is filed if he is specifically named as a party plaintiff in the complaint, or if his name did not so appear, on the subsequent date on which his name is added as a party plaintiff in such action. The authority and requirements described in this subsection shall apply with respect to a violation of section 203(m)(2)(B) of this title, as appropriate, and the employer shall be liable for the amount of the sum of any tip credit taken by the employer and all such tips unlawfully kept by the employer, and an additional equal amount as liquidated damages.
In any action or proceeding commenced prior to, on, or after August 8, 1956, no employer shall be subject to any liability or punishment under this chapter or the Portal-to-Portal Act of 1947 [29 U.S.C. 251 et seq.] on account of his failure to comply with any provision or provisions of this chapter or such Act (1) with respect to work heretofore or hereafter performed in a workplace to which the exemption in section 213(f) of this title is applicable, (2) with respect to work performed in Guam, the Canal Zone or Wake Island before the effective date of this amendment of subsection (d), or (3) with respect to work performed in a possession named in section 206(a)(3)  of this title at any time prior to the establishment by the Secretary, as provided therein, of a minimum wage rate applicable to such work.