Use Form 843 to claim a refund or request an abatement of certain taxes, interest, penalties, fees, and additions to tax. The primary letter we use to request information about a return is Form DTF948 or DTF948O, Request for Information (RFI).Use Form 843 to claim a refund or request an abatement of certain taxes, penalties, additions to tax, interest, and fees. In this video we'll be going over IRS form 843 claim for refund and request for abatement. Write the word "Amended" in bold letters in the upper right-hand corner of the return. You must submit the Employer Certification Letter as it appears in the template. Revenue will reject any requests with changes to the template. The instruction and template sheet includes a template form for your employer to copy, complete, and sign, on their letterhead. The IRS uses refund traces to track lost or stolen checks or verify whether a check was deposited. Request for Transcript of Tax Return.