A discrepancy is a question to explain with relevant sources. Keep the IRS statement and your related evidence separately identifiable during the review discussion.
Describe what appears different
Identify the amount, period or description in the actual notice, then say what the other source shows. Keep complete context rather than only a cropped figure. A difference does not automatically establish its cause or the correct account treatment. Preserve uncertainty honestly, including missing confirmation or an unclear period relationship, so proposed help addresses the point instead of accepting a convenient explanation as already proved.
Select a useful next comparison
Ask which additional evidence could clarify the relationship and why it matters to the account concern. Understand the proposed task, charges and authority before proceeding. Keep a later explanation separately sourced and dated rather than change the originals to make them agree. The opening can make assistance useful while background remains incomplete, with formal account action and any IRS determination following their own applicable requirements separately.