Note: You must complete a separate Form 3911 for each refund for which you are requesting information. Use Form 843 to claim a refund or request an abatement of certain taxes, interest, penalties, fees, and additions to tax.Applicant will receive a letter indicating that the claim is being transferred. • The claimant may request to schedule a hearing. You can find the CP or LTR number on the right corner of the letter. The primary letter we use to request information about a return is Form DTF948 or DTF948O, Request for Information (RFI). Most IRS letters and notices are about federal tax returns or tax accounts. If you meet the age exemption AND your employer withheld local income tax you may be eligible for a refund. Fill out the Form 10A to apply for a refund. Unless you receive a letter from us requesting additional information, your return is still being processed.