Common payroll errors that impact retroactive pay include; Failing to include the overtime rate Miscalculations due to shift differentials where an employer fails to pay an increased rate Delay in paying commissions Forgetting to pay the new rate after an employee receives an increase Supplemental wages may include bonuses, miscellaneous income, and cashed-out vacation. All of this income should be considered for retroactive pay. A union collective agreement includes a provision that workers are entitled to retroactive pay, and should highlight how far back these retroactive claims can go. Retroactive pay can also be court-ordered in the instance of an employer going to court for the following reasons; Discrimination Retaliation Breach of contract Minimum wage violations that contradict the Fair Labor Standards Act (FLSA)