Overpayments. To receive important letters about overpayment recovery waivers, please ensure your mailing address is updated in your IDES account. If an overpayment is not discovered and one or more paydays have passed, the employer and employee shall agree on a repayment schedule.If an overpayment is not discovered until one or more paydays have passed, the employer and employee shall agree on a repayment schedule. Include all written documentation to support or defend that an overpayment occurred. In the notice, IDES will ask you to pay back the overpayment. You do not have to agree to do so. Write an email to your payroll department and tell them how much you were overpaid. Ask for direction on how to proceed. Use ACM to complete Form 2404, Referral of Overpayment, and Form 2404X, Notice of Overpayment. NOTE: All overpayments must be processed through ACM except:.