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.Your claim must state all of the following: The specific reasons you paid too much tax. The amount of tax you overpaid. 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. Please download the form, complete each field and print. Include the form with your refund so we can properly apply the refund and record the receipt. Taxpayers use Form 843 to claim a refund (or abatement) of certain overpaid (or overassessed) taxes, interest, penalties, and additions to tax. Overpayments are subject to refund only if a claim is filed with the Office of Finance within one (1) year from the date of payment.