Complete your protest and mail it to the IRS address on the letter that explains your appeal rights. How to Write a Tax Protest Letter to the IRS Contesting an Issue.Sending an IRS audit reconsideration request? 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. Use Form 12203, Request for Appeals Review, or the form referenced in the letter to file your appeal, or prepare a brief written statement. I am writing to request an appeal of the dismissal decision. Fill out and submit this form. You can find the CP or LTR number on the right corner of the letter. Also send or give a copy to the auditor.