Letters 525 and 915 outline your options should you not agree with the proposed adjustments. If you agree with the adjustments, you sign and return the agreement form. If you do not agree, respond to the IRS by the due date on the letter. This could include sending additional documentation or an explanation to support your position. If you need more time to submit your response, call the number on the letter before the due date to ask for additional time.

If the examiner still proposes a change to your tax return, you can request an informal conference with the examiner’s manager prior to the response date in the letter. If you still disagree, you can request a conference with the IRS Independent Office of Appeals (Appeals) prior to the date in the letter. Make this request in writing and include your reasons for disagreeing with the IRS. Generally, you must request an Appeals conference within 30 days from the date of your letter to be given consideration. Review the procedures for appealing an IRS determination as outlined in Publication 3498, The Examination Process, or Publication 3498-A, The Examination Process (Examinations by Mail), to ensure that your request for an Appeals conference meets any requirements specified.

The IRS may disallow what you claimed on your return and issue a Notice of Deficiency, Letter 3219 (if your audit was conducted by mail) or Letter 531 (if you had an in-person audit). This legal notice gives you 90 days to petition the United States Tax Court (you have 150 days if the notice is addressed to a person outside the United States).