Complete your protest and mail it to the IRS address on the letter that explains your appeal rights. This form is to be used to request an Appeals review upon completion of an examination (audit) if you do not agree with our proposed changes from the audit.A letter of appeal is more effective when it's written concisely and contains complete information that can help the IRS gauge the validity of your protest. Purpose of this form: You can use this form to appeal a Letter 4890 Notice of Denial or a Letter 5015 Notice of Revocation of your IRS-approved. Your letter should clearly state your disagreement with the IRS decision or notice and provide specific reasons for your appeal. This booklet is designed to help taxpayers and assessors understand the overall process of appealing a real estate tax assessment.