These FAQs outline how to respond to an overpayment letter and provide guidance on next steps. You can also reach out to our Phoenix team through the Contact Us form and select the option "Phoenix – Overpayments.We have identified the following overpayment and are in good faith voluntarily refunding all monies collected in error. The salary overpayment resulted because . In this article, we'll show you how to write a refund request letter template that not only grabs attention but also persuades companies to act in your favor. The IRS uses Letter 3286C to inform you that they believe you may have overpaid for a particular year and will refund you the difference. Make sure to fill out Annex B in your overpayment letter within the deadline provided even if you file a grievance.