Your claim must state all of the following: The specific reasons you paid too much tax. The amount of tax you overpaid.A claim for refund is a request for reimbursement of amounts previously paid. Generally, if you have paid your balance in full you will file a formal claim. In this video we will show you how to file a claim for refund. If you believe you have overpaid an amount and you wish to receive a refund of the overpaid amount, you must file a claim for refund with the CDTFA. Blue Shield will request a refund of the overpayment within 365 days of the original payment date. If we have identified an overpayment and request a refund, please mail the check along with a copy of the overpayment request letter we sent you. Overpayments and repayments are two of the most common anomalies that could complicate yearend and W2 processing.