Use Form 843 to claim a refund or request an abatement of certain taxes, interest, penalties, fees, and additions to tax. We issue Notice CP12 when we correct one or more mistakes on your tax return, and: The overpayment is different from the one you expected.Use this page to find answers for topics related to the Middle Class Tax Refund (MCTR) payment. Using your debit card. The letter should explain why you are claiming the refund and the amount of money you are asking the IRS to return to you.