The law basically states that an overpayment is treated as an advance that can be deducted from future paychecks. This model letter as a legally approved form for a client to use when informing an employee about correcting a wage overpayment.The salary overpayment resulted because . Section 18, Chapter. If you pay an employee more than they should have received in a pay period, you need to know how to correct a payroll overpayment. The Dallas County Administrative Code contains the employment policies and procedures for Dallas County.